aboutsummaryrefslogblamecommitdiffstats
path: root/erts/emulator/beam/bif.c
blob: b3325d635be865c772f70588e1cf2ade2083a8c3 (plain) (tree)
1
2
3
4
5
6
7
8
9
10
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280

                   
  
                                                        
  




                                                                      
  



                                                                         
  

































































































































































































































































































































































                                                                               











                                                            









































































































































































































































                                                                              
                                
                   
                        




                                                                         
                          























































































































































































                                                                               



                                        
                                                                           
                          





































                                                                             








                                                                               




































































































































































































































                                                                               


                                                                        
       









                                                                                




































                                                                        



























                                                                        






























































































































































































                                                                                


                                                
                                        










































































































































































                                                                                
















                                                             






























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































                                                                                                  

                                                                   



                                                            
                      













                                                                        
                                                                  









                                                  
                      
















































                                                                        
                                                                  




















































































































                                                                                  
                                                                


























                                                                                      
                 

                          
                                                           
                                                                                             
     

                          
                                                                                     
      








































































































                                                                            
                                   


                                            
                                                           



















































































































































































                                                                           

                                                                   


                                               
 


                                                                      



                                                         
                                               



















                                                                      



























































































                                                                         
                                      






































































                                                                                     
                                      
















































































































































                                                                                    
                                                                   














                                                                     

                                                                  













                                                                           









































































                                                                       
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 1996-2011. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <stddef.h> /* offsetof() */
#include "sys.h"
#include "erl_vm.h"
#include "erl_sys_driver.h"
#include "global.h"
#include "erl_process.h"
#include "error.h"
#include "bif.h"
#include "big.h"
#include "dist.h"
#include "erl_version.h"
#include "erl_binary.h"
#include "beam_bp.h"
#include "erl_db_util.h"
#include "register.h"

static Export* flush_monitor_message_trap = NULL;
static Export* set_cpu_topology_trap = NULL;
static Export* await_proc_exit_trap = NULL;
Export* erts_format_cpu_topology_trap = NULL;

#define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)

/*
 * The BIF's now follow, see the Erlang Manual for a description of what
 * each individual BIF does.
 */

BIF_RETTYPE spawn_3(BIF_ALIST_3)
{
    ErlSpawnOpts so;
    Eterm pid;

    so.flags = 0;
    pid = erl_create_process(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, &so);
    if (is_non_value(pid)) {
	BIF_ERROR(BIF_P, so.error_code);
    } else {
	if (ERTS_USE_MODIFIED_TIMING()) {
	    BIF_TRAP2(erts_delay_trap, BIF_P, pid, ERTS_MODIFIED_TIMING_DELAY);
	}
	BIF_RET(pid);
    }
}

/**********************************************************************/

/* Utility to add a new link between processes p and another internal
 * process (rpid). Process p must be the currently executing process.
 */
static int insert_internal_link(Process* p, Eterm rpid)
{
    Process *rp;
    ErtsProcLocks rp_locks = ERTS_PROC_LOCK_LINK;

    ASSERT(is_internal_pid(rpid));

#ifdef ERTS_SMP
    if (IS_TRACED(p) && (p->trace_flags & (F_TRACE_SOL|F_TRACE_SOL1)))
	rp_locks = ERTS_PROC_LOCKS_ALL;

    erts_smp_proc_lock(p, ERTS_PROC_LOCK_LINK);
#endif

    /* get a pointer to the process struct of the linked process */
    rp = erts_pid2proc_opt(p, ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
			   rpid, rp_locks,
			   ERTS_P2P_FLG_ALLOW_OTHER_X);

    if (!rp) {
	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	return 0;
    }

    if (p != rp) {
	erts_add_link(&(p->nlinks), LINK_PID, rp->id);
	erts_add_link(&(rp->nlinks), LINK_PID, p->id);

	ASSERT(is_nil(p->tracer_proc)
	       || is_internal_pid(p->tracer_proc)
	       || is_internal_port(p->tracer_proc));

	if (IS_TRACED(p)) {
	    if (p->trace_flags & (F_TRACE_SOL|F_TRACE_SOL1))  {
		rp->trace_flags |= (p->trace_flags & TRACEE_FLAGS);
		rp->tracer_proc = p->tracer_proc; /* maybe steal */

		if (p->trace_flags & F_TRACE_SOL1)  { /* maybe override */
		    rp->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
		    p->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
		}
	    }
	}
    }
    if (IS_TRACED_FL(rp, F_TRACE_PROCS))
	trace_proc(p, rp, am_getting_linked, p->id);

    if (p == rp)
	erts_smp_proc_unlock(p, rp_locks & ~ERTS_PROC_LOCK_MAIN);
    else {
	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	erts_smp_proc_unlock(rp, rp_locks);
    }

    return 1;
}


/* create a link to the process */
BIF_RETTYPE link_1(BIF_ALIST_1)
{
    DistEntry *dep;

    if (IS_TRACED_FL(BIF_P, F_TRACE_PROCS)) {
	trace_proc(BIF_P, BIF_P, am_link, BIF_ARG_1);
    }
    /* check that the pid or port which is our argument is OK */

    if (is_internal_pid(BIF_ARG_1)) {
	if (internal_pid_index(BIF_ARG_1) >= erts_max_processes) {
	    BIF_ERROR(BIF_P, BADARG);
	}

	if (insert_internal_link(BIF_P, BIF_ARG_1)) {
	    BIF_RET(am_true);
	}
	else {
	    goto res_no_proc;
	}
    }

    if (is_internal_port(BIF_ARG_1)) {
	Port *pt = erts_id2port(BIF_ARG_1, BIF_P, ERTS_PROC_LOCK_MAIN);
	if (!pt) {
	    goto res_no_proc;
	}

	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
	
	if (erts_add_link(&(BIF_P->nlinks), LINK_PID, BIF_ARG_1) >= 0)
	    erts_add_link(&(pt->nlinks), LINK_PID, BIF_P->id);
	/* else: already linked */

	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
	erts_smp_port_unlock(pt);
	BIF_RET(am_true);
    }
    else if (is_external_port(BIF_ARG_1)
	     && external_port_dist_entry(BIF_ARG_1) == erts_this_dist_entry) {
	goto res_no_proc;
    }

    if (is_external_pid(BIF_ARG_1)) {

	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);

	/* We may earn time by checking first that we're not linked already */
	if (erts_lookup_link(BIF_P->nlinks, BIF_ARG_1) != NULL) {
	    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
	    BIF_RET(am_true);
	}
	else {
	    ErtsLink *lnk;
	    int code;
	    ErtsDSigData dsd;
	    dep = external_pid_dist_entry(BIF_ARG_1);
	    if (dep == erts_this_dist_entry) {
		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
		goto res_no_proc;
	    }

	    code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_RLOCK, 0);
	    switch (code) {
	    case ERTS_DSIG_PREP_NOT_ALIVE:
		/* Let the dlink trap handle it */
	    case ERTS_DSIG_PREP_NOT_CONNECTED:
		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
		BIF_TRAP1(dlink_trap, BIF_P, BIF_ARG_1);

	    case ERTS_DSIG_PREP_CONNECTED:
		/* We are connected. Setup link and send link signal */

		erts_smp_de_links_lock(dep);

		erts_add_link(&(BIF_P->nlinks), LINK_PID, BIF_ARG_1);
		lnk = erts_add_or_lookup_link(&(dep->nlinks),
					      LINK_PID,
					      BIF_P->id);
		ASSERT(lnk != NULL);
		erts_add_link(&ERTS_LINK_ROOT(lnk), LINK_PID, BIF_ARG_1);

		erts_smp_de_links_unlock(dep);
		erts_smp_de_runlock(dep);
		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);

		code = erts_dsig_send_link(&dsd, BIF_P->id, BIF_ARG_1);
		if (code == ERTS_DSIG_SEND_YIELD)
		    ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
		BIF_RET(am_true);
	    default:
		ASSERT(! "Invalid dsig prepare result");
		BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
	    }
	}
    }

    BIF_ERROR(BIF_P, BADARG);

 res_no_proc:
    if (BIF_P->flags & F_TRAPEXIT) {
	ErtsProcLocks locks = ERTS_PROC_LOCK_MAIN;
	erts_deliver_exit_message(BIF_ARG_1, BIF_P, &locks, am_noproc, NIL);
	erts_smp_proc_unlock(BIF_P, ~ERTS_PROC_LOCK_MAIN & locks);
	BIF_RET(am_true);
    }
    else
	BIF_ERROR(BIF_P, EXC_NOPROC);
}

#define ERTS_DEMONITOR_FALSE		2
#define ERTS_DEMONITOR_TRUE		1
#define ERTS_DEMONITOR_BADARG		0
#define ERTS_DEMONITOR_YIELD_TRUE	-1
#define ERTS_DEMONITOR_INTERNAL_ERROR	-2

static int
remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
{
    ErtsDSigData dsd;
    ErtsMonitor *dmon;
    ErtsMonitor *mon;
    int code;
    int res;
#ifndef ERTS_SMP
    int stale_mon = 0;
#endif

    ERTS_SMP_LC_ASSERT((ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK)
		       == erts_proc_lc_my_proc_locks(c_p));

    code = erts_dsig_prepare(&dsd, dep, c_p, ERTS_DSP_RLOCK, 0);
    switch (code) {
    case ERTS_DSIG_PREP_NOT_ALIVE:
    case ERTS_DSIG_PREP_NOT_CONNECTED:
#ifndef ERTS_SMP
	/* XXX Is this possible? Shouldn't this link
	   previously have been removed if the node
	   had previously been disconnected. */
	ASSERT(0);
	stale_mon = 1;
#endif
	/*
	 * In the smp case this is possible if the node goes
	 * down just before the call to demonitor.
	 */
	if (dep) {
	    erts_smp_de_links_lock(dep);
	    dmon = erts_remove_monitor(&dep->monitors, ref);
	    erts_smp_de_links_unlock(dep);
	    if (dmon)
		erts_destroy_monitor(dmon);
	}
	mon = erts_remove_monitor(&c_p->monitors, ref);
	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_LINK);

	res = ERTS_DEMONITOR_TRUE;
	break;

    case ERTS_DSIG_PREP_CONNECTED:

	erts_smp_de_links_lock(dep);
	mon = erts_remove_monitor(&c_p->monitors, ref);
	dmon = erts_remove_monitor(&dep->monitors, ref);
	erts_smp_de_links_unlock(dep);
	erts_smp_de_runlock(dep);
	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_LINK);

	if (!dmon) {
#ifndef ERTS_SMP
	    /* XXX How is this possible? Shouldn't this link
	       previously have been removed when the distributed
	       end was removed. */
	    ASSERT(0);
	    stale_mon = 1;
#endif
	    /*
	     * This is possible when smp support is enabled.
	     * 'DOWN' message just arrived.
	     */
	    res = ERTS_DEMONITOR_TRUE;
	}
	else {
	    /*
	     * Soft (no force) send, use ->data in dist slot 
	     * monitor list since in case of monitor name 
	     * the atom is stored there. Yield if necessary.
	     */
	    code = erts_dsig_send_demonitor(&dsd,
					    c_p->id, 
					    (mon->name != NIL
					     ? mon->name
					     : mon->pid), 
					    ref,
					    0);
	    res = (code == ERTS_DSIG_SEND_YIELD
		   ? ERTS_DEMONITOR_YIELD_TRUE
		   : ERTS_DEMONITOR_TRUE);
	    erts_destroy_monitor(dmon);

	}
	break;
    default:
	ASSERT(! "Invalid dsig prepare result");
	res = ERTS_DEMONITOR_INTERNAL_ERROR;
	break;
    }

#ifndef ERTS_SMP
    if (stale_mon) {
	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
	erts_dsprintf(dsbufp, "Stale process monitor %T to ", ref);
	if (is_atom(to))
	    erts_dsprintf(dsbufp, "{%T, %T}", to, dep->sysname);
	else
	    erts_dsprintf(dsbufp, "%T", to);
	erts_dsprintf(dsbufp, " found\n");
	erts_send_error_to_logger(c_p->group_leader, dsbufp);
    }
#endif

    /*
     * We aren't allowed to destroy 'mon' until now, since 'to'
     * may refer into 'mon' (external pid).
     */
    ASSERT(mon); /* Since link lock wasn't released between
		    lookup and remove */
    erts_destroy_monitor(mon);

    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN == erts_proc_lc_my_proc_locks(c_p));
    return res;
}

static int demonitor(Process *c_p, Eterm ref)
{
   ErtsMonitor *mon = NULL;  /* The monitor entry to delete */
   Process  *rp;    /* Local target process */
   Eterm     to = NIL;    /* Monitor link traget */
   DistEntry *dep = NULL;  /* Target's distribution entry */
   int deref_de = 0;
   int res;
   int unlock_link = 1;


   erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_LINK);

   if (is_not_internal_ref(ref)) {
       res = ERTS_DEMONITOR_BADARG;
       goto done; /* Cannot be this monitor's ref */
   }

   mon = erts_lookup_monitor(c_p->monitors, ref);
   if (!mon) {
       res = ERTS_DEMONITOR_FALSE;
       goto done;
   }

   if (mon->type != MON_ORIGIN) {
       res = ERTS_DEMONITOR_BADARG;
       goto done;
   }
   to = mon->pid;

   if (is_atom(to)) {
       /* Monitoring a name at node to */
       ASSERT(is_node_name_atom(to));
       dep = erts_sysname_to_connected_dist_entry(to);
       ASSERT(dep != erts_this_dist_entry);
       if (dep)
	   deref_de = 1;
   } else {
       ASSERT(is_pid(to));
       dep = pid_dist_entry(to);
   }
   if (dep != erts_this_dist_entry) {
       res = remote_demonitor(c_p, dep, ref, to);
       /* remote_demonitor() unlocks link lock on c_p */
       unlock_link = 0;
   }
   else { /* Local monitor */
       if (deref_de) {
	   deref_de = 0;
	   erts_deref_dist_entry(dep);
       }
       dep = NULL;
       rp = erts_pid2proc_opt(c_p,
			      ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
			      to,
			      ERTS_PROC_LOCK_LINK,
			      ERTS_P2P_FLG_ALLOW_OTHER_X);
       mon = erts_remove_monitor(&c_p->monitors, ref);
#ifndef ERTS_SMP
       ASSERT(mon);
#else
       if (!mon)
	   res = ERTS_DEMONITOR_FALSE;
       else
#endif
       {
	   res = ERTS_DEMONITOR_TRUE;
	   erts_destroy_monitor(mon);
       }
       if (rp) {
	   ErtsMonitor *rmon;
	   rmon = erts_remove_monitor(&(rp->monitors), ref);
	   if (rp != c_p)
	       erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
	   if (rmon != NULL)
	       erts_destroy_monitor(rmon);
       }
       else {
	   ERTS_SMP_ASSERT_IS_NOT_EXITING(c_p);
       }

   }

 done:

   if (unlock_link)
       erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_LINK);

   if (deref_de) {
       ASSERT(dep);
       erts_deref_dist_entry(dep);
   }

   ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN == erts_proc_lc_my_proc_locks(c_p));
   return res;
}

BIF_RETTYPE demonitor_1(BIF_ALIST_1)
{
    switch (demonitor(BIF_P, BIF_ARG_1)) {
    case ERTS_DEMONITOR_FALSE:
    case ERTS_DEMONITOR_TRUE:
	BIF_RET(am_true);
    case ERTS_DEMONITOR_YIELD_TRUE:
	ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
    case ERTS_DEMONITOR_BADARG:
	BIF_ERROR(BIF_P, BADARG);
    case ERTS_DEMONITOR_INTERNAL_ERROR:
    default:
	ASSERT(! "demonitor(): internal error");
	BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
    }
}

BIF_RETTYPE demonitor_2(BIF_ALIST_2)
{
    Eterm res = am_true;
    int info = 0;
    int flush = 0;
    Eterm list = BIF_ARG_2;

    while (is_list(list)) {
	Eterm* consp = list_val(list);
	switch (CAR(consp)) {
	case am_flush:
	    flush = 1;
	    break;
	case am_info:
	    info = 1;
	    break;
	default:
	    goto badarg;
	}
	list = CDR(consp);	
    }

    if (is_not_nil(list))
	goto badarg;

    switch (demonitor(BIF_P, BIF_ARG_1)) {
    case ERTS_DEMONITOR_FALSE:
	if (info)
	    res = am_false;
	if (flush)
	    BIF_TRAP2(flush_monitor_message_trap, BIF_P, BIF_ARG_1, res);
    case ERTS_DEMONITOR_TRUE:
	BIF_RET(res);
    case ERTS_DEMONITOR_YIELD_TRUE:
	ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
    case ERTS_DEMONITOR_BADARG:
    badarg:
	BIF_ERROR(BIF_P, BADARG);
    case ERTS_DEMONITOR_INTERNAL_ERROR:
    default:
	ASSERT(! "demonitor(): internal error");
	BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
    }
}

/* Type must be atomic object! */
void
erts_queue_monitor_message(Process *p,
			   ErtsProcLocks *p_locksp,
			   Eterm ref,
			   Eterm type,
			   Eterm item,
			   Eterm reason)
{
    Eterm tup;
    Eterm* hp;
    Eterm reason_copy, ref_copy, item_copy;
    Uint reason_size, ref_size, item_size, heap_size;
    ErlOffHeap *ohp;
    ErlHeapFragment *bp;

    reason_size = IS_CONST(reason) ? 0 : size_object(reason);
    item_size   = IS_CONST(item) ? 0 : size_object(item);
    ref_size    = size_object(ref);

    heap_size = 6+reason_size+ref_size+item_size;

    hp = erts_alloc_message_heap(heap_size,
				 &bp,
				 &ohp,
				 p,
				 p_locksp);

    reason_copy = (IS_CONST(reason)
		   ? reason
		   : copy_struct(reason, reason_size, &hp, ohp));
    item_copy   = (IS_CONST(item)
		   ? item
		   : copy_struct(item, item_size, &hp, ohp));
    ref_copy    = copy_struct(ref, ref_size, &hp, ohp);

    tup = TUPLE5(hp, am_DOWN, ref_copy, type, item_copy, reason_copy);
    erts_queue_message(p, p_locksp, bp, tup, NIL);
}

static BIF_RETTYPE
local_pid_monitor(Process *p, Eterm target)
{
    BIF_RETTYPE ret;
    Eterm mon_ref;
    Process *rp;
    ErtsProcLocks p_locks = ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK;

    mon_ref = erts_make_ref(p);
    ERTS_BIF_PREP_RET(ret, mon_ref);
    if (target == p->id) {
	return ret;
    }

    erts_smp_proc_lock(p, ERTS_PROC_LOCK_LINK);
    rp = erts_pid2proc_opt(p, p_locks,
			   target, ERTS_PROC_LOCK_LINK,
			   ERTS_P2P_FLG_ALLOW_OTHER_X);
    if (!rp) {
	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	p_locks &= ~ERTS_PROC_LOCK_LINK;
	erts_queue_monitor_message(p, &p_locks,
				   mon_ref, am_process, target, am_noproc);
    }
    else {
	ASSERT(rp != p);

	erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, target, NIL);
	erts_add_monitor(&(rp->monitors), MON_TARGET, mon_ref, p->id, NIL);

	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
    }

    erts_smp_proc_unlock(p, p_locks & ~ERTS_PROC_LOCK_MAIN);

    return ret;
}

static BIF_RETTYPE
local_name_monitor(Process *p, Eterm target_name)
{
    BIF_RETTYPE ret;
    Eterm mon_ref;
    ErtsProcLocks p_locks = ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK;
    Process *rp;

    mon_ref = erts_make_ref(p);
    ERTS_BIF_PREP_RET(ret, mon_ref);
    erts_smp_proc_lock(p, ERTS_PROC_LOCK_LINK);
    rp = erts_whereis_process(p, p_locks, target_name, ERTS_PROC_LOCK_LINK,
			      ERTS_P2P_FLG_ALLOW_OTHER_X);
    if (!rp) {
	DeclareTmpHeap(lhp,3,p);
	Eterm item;
	UseTmpHeap(3,p);
	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	p_locks &= ~ERTS_PROC_LOCK_LINK;
	item = TUPLE2(lhp, target_name, erts_this_dist_entry->sysname);
	erts_queue_monitor_message(p, &p_locks,
				   mon_ref, am_process, item, am_noproc);
	UnUseTmpHeap(3,p);
    }
    else if (rp != p) {
	erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, rp->id,
			 target_name);
	erts_add_monitor(&(rp->monitors), MON_TARGET, mon_ref, p->id,
			 target_name);
	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
    }

    erts_smp_proc_unlock(p, p_locks & ~ERTS_PROC_LOCK_MAIN);

    return ret;
}

static BIF_RETTYPE
remote_monitor(Process *p, Eterm bifarg1, Eterm bifarg2,
	       DistEntry *dep, Eterm target, int byname)
{
    ErtsDSigData dsd;
    BIF_RETTYPE ret;
    int code;

    erts_smp_proc_lock(p, ERTS_PROC_LOCK_LINK);
    code = erts_dsig_prepare(&dsd, dep, p, ERTS_DSP_RLOCK, 0);
    switch (code) {
    case ERTS_DSIG_PREP_NOT_ALIVE:
	/* Let the dmonitor_p trap handle it */
    case ERTS_DSIG_PREP_NOT_CONNECTED:
	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	ERTS_BIF_PREP_TRAP2(ret, dmonitor_p_trap, p, bifarg1, bifarg2);
	break;
    case ERTS_DSIG_PREP_CONNECTED:
	if (!(dep->flags & DFLAG_DIST_MONITOR)
	    || (byname && !(dep->flags & DFLAG_DIST_MONITOR_NAME))) {
	    erts_smp_de_runlock(dep);
	    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
	    ERTS_BIF_PREP_ERROR(ret, p, BADARG);
	}
	else {
	    Eterm p_trgt, p_name, d_name, mon_ref;

	    mon_ref = erts_make_ref(p);

	    if (byname) {
		p_trgt = dep->sysname;
		p_name = target;
		d_name = target;
	    }
	    else {
		p_trgt = target;
		p_name = NIL;
		d_name = NIL;
	    }

	    erts_smp_de_links_lock(dep);

	    erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, p_trgt,
			     p_name);
	    erts_add_monitor(&(dep->monitors), MON_TARGET, mon_ref, p->id,
			     d_name);

	    erts_smp_de_links_unlock(dep);
	    erts_smp_de_runlock(dep);
	    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);

	    code = erts_dsig_send_monitor(&dsd, p->id, target, mon_ref);
	    if (code == ERTS_DSIG_SEND_YIELD)
		ERTS_BIF_PREP_YIELD_RETURN(ret, p, mon_ref);
	    else
		ERTS_BIF_PREP_RET(ret, mon_ref);
	}
	break;
    default:
	ASSERT(! "Invalid dsig prepare result");
	ERTS_BIF_PREP_ERROR(ret, p, EXC_INTERNAL_ERROR);
	break;
    }

    return ret;
}
	
BIF_RETTYPE monitor_2(BIF_ALIST_2)
{
    Eterm target = BIF_ARG_2;
    BIF_RETTYPE ret;
    DistEntry  *dep = NULL; 
    int deref_de = 0;

    /* Only process monitors are implemented */
    if (BIF_ARG_1 != am_process) {
	goto error;
    }

    if (is_internal_pid(target)) {
    local_pid:
	ret = local_pid_monitor(BIF_P, target);
    } else if (is_external_pid(target)) {
	dep = external_pid_dist_entry(target);
	if (dep == erts_this_dist_entry)
	    goto local_pid;
	ret = remote_monitor(BIF_P, BIF_ARG_1, BIF_ARG_2, dep, target, 0);
    } else if (is_atom(target)) {
	ret = local_name_monitor(BIF_P, target);
    } else if (is_tuple(target)) {
	Eterm *tp = tuple_val(target);
	Eterm remote_node;
	Eterm name;
	if (arityval(*tp) != 2) 
	    goto error;
	remote_node = tp[2];
	name = tp[1];
	if (!is_atom(remote_node) || !is_atom(name)) {
	    goto error;
	}
	if (!erts_is_alive && remote_node != am_Noname) {
	    goto error; /* Remote monitor from (this) undistributed node */
	}
	dep = erts_sysname_to_connected_dist_entry(remote_node);
	if (dep == erts_this_dist_entry) {
	    deref_de = 1;
	    ret = local_name_monitor(BIF_P, name);
	} else {
	    if (dep)
		deref_de = 1;
	    ret = remote_monitor(BIF_P, BIF_ARG_1, BIF_ARG_2, dep, name, 1);
	}
    } else {
    error:
	ERTS_BIF_PREP_ERROR(ret, BIF_P, BADARG);
    }
    if (deref_de) {
	deref_de = 0;
	erts_deref_dist_entry(dep);
    }

    return ret;
}


/**********************************************************************/
/* this is a combination of the spawn and link BIFs */

BIF_RETTYPE spawn_link_3(BIF_ALIST_3)
{
    ErlSpawnOpts so;
    Eterm pid;

    so.flags = SPO_LINK;
    pid = erl_create_process(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, &so);
    if (is_non_value(pid)) {
	BIF_ERROR(BIF_P, so.error_code);
    } else {
	if (ERTS_USE_MODIFIED_TIMING()) {
	    BIF_TRAP2(erts_delay_trap, BIF_P, pid, ERTS_MODIFIED_TIMING_DELAY);
	}
	BIF_RET(pid);
    }
}

/**********************************************************************/

BIF_RETTYPE spawn_opt_1(BIF_ALIST_1)
{
    ErlSpawnOpts so;
    Eterm pid;
    Eterm* tp;
    Eterm ap;
    Eterm arg;
    Eterm res;

    /*
     * Check that the first argument is a tuple of four elements.
     */
    if (is_not_tuple(BIF_ARG_1)) {
    error:
	BIF_ERROR(BIF_P, BADARG);
    }
    tp = tuple_val(BIF_ARG_1);
    if (*tp != make_arityval(4))
	goto error;

    /*
     * Store default values for options.
     */
    so.flags          = SPO_USE_ARGS;
    so.min_heap_size  = H_MIN_SIZE;
    so.min_vheap_size = BIN_VH_MIN_SIZE;
    so.priority       = PRIORITY_NORMAL;
    so.max_gen_gcs    = (Uint16) erts_smp_atomic32_read(&erts_max_gen_gcs);
    so.scheduler      = 0;

    /*
     * Walk through the option list.
     */
    ap = tp[4];
    while (is_list(ap)) {
	arg = CAR(list_val(ap));
	if (arg == am_link) {
	    so.flags |= SPO_LINK;
	} else if (arg == am_monitor) {
	    so.flags |= SPO_MONITOR;
	} else if (is_tuple(arg)) {
	    Eterm* tp2 = tuple_val(arg);
	    Eterm val;
	    if (*tp2 != make_arityval(2))
		goto error;
	    arg = tp2[1];
	    val = tp2[2];
	    if (arg == am_priority) {
		if (val == am_max)
		    so.priority = PRIORITY_MAX;
		else if (val == am_high)
		    so.priority = PRIORITY_HIGH;
		else if (val == am_normal)
		    so.priority = PRIORITY_NORMAL;
		else if (val == am_low)
		    so.priority = PRIORITY_LOW;
		else
		    goto error;
	    } else if (arg == am_min_heap_size && is_small(val)) {
		Sint min_heap_size = signed_val(val);
		if (min_heap_size < 0) {
		    goto error;
		} else if (min_heap_size < H_MIN_SIZE) {
		    so.min_heap_size = H_MIN_SIZE;
		} else {
		    so.min_heap_size = erts_next_heap_size(min_heap_size, 0);
		}
	    } else if (arg == am_min_bin_vheap_size && is_small(val)) {
		Sint min_vheap_size = signed_val(val);
		if (min_vheap_size < 0) {
		    goto error;
		} else if (min_vheap_size < BIN_VH_MIN_SIZE) {
		    so.min_vheap_size = BIN_VH_MIN_SIZE;
		} else {
		    so.min_vheap_size = erts_next_heap_size(min_vheap_size, 0);
		}
	    } else if (arg == am_fullsweep_after && is_small(val)) {
		Sint max_gen_gcs = signed_val(val);
		if (max_gen_gcs < 0) {
		    goto error;
		} else {
		    so.max_gen_gcs = max_gen_gcs;
		}
	    } else if (arg == am_scheduler && is_small(val)) {
		Sint scheduler = signed_val(val);
		if (erts_common_run_queue && erts_no_schedulers > 1)
		    goto error;
		if (scheduler < 0 || erts_no_schedulers < scheduler)
		    goto error;
		so.scheduler = (int) scheduler;
	    } else {
		goto error;
	    }
	} else {
	    goto error;
	}
	ap = CDR(list_val(ap));
    }
    if (is_not_nil(ap)) {
	goto error;
    }

    /*
     * Spawn the process.
     */
    pid = erl_create_process(BIF_P, tp[1], tp[2], tp[3], &so);
    if (is_non_value(pid)) {
	BIF_ERROR(BIF_P, so.error_code);
    } else if (so.flags & SPO_MONITOR) {
	Eterm* hp = HAlloc(BIF_P, 3);
	res = TUPLE2(hp, pid, so.mref);
    } else {
	res = pid;
    }

    if (ERTS_USE_MODIFIED_TIMING()) {
	BIF_TRAP2(erts_delay_trap, BIF_P, res, ERTS_MODIFIED_TIMING_DELAY);
    }
    else {
	BIF_RET(res);
    }
}

  
/**********************************************************************/
/* remove a link from a process */
BIF_RETTYPE unlink_1(BIF_ALIST_1)
{
    Process *rp;
    DistEntry *dep;
    ErtsLink *l = NULL, *rl = NULL;

    /*
     * SMP specific note concerning incoming exit signals:
     *   We have to have at least the status lock during removal of
     *   the link half on current process, and check for and handle
     *   a present pending exit while the status lock is held. This
     *   in order to ensure that we wont be exited by a link after
     *   it has been removed.
     *
     *   (We also have to have the link lock, of course, in order to
     *    be allowed to remove the link...)
     */

    if (IS_TRACED_FL(BIF_P, F_TRACE_PROCS)) {
	trace_proc(BIF_P, BIF_P, am_unlink, BIF_ARG_1);
    }

    if (is_internal_port(BIF_ARG_1)) {
	Port *pt = erts_id2port_sflgs(BIF_ARG_1,
				      BIF_P,
				      ERTS_PROC_LOCK_MAIN,
				      ERTS_PORT_SFLGS_DEAD);

	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
#ifdef ERTS_SMP
	if (ERTS_PROC_PENDING_EXIT(BIF_P)) {
	    if (pt)
		erts_smp_port_unlock(pt);
	    goto handle_pending_exit;
	}
#endif

	l = erts_remove_link(&BIF_P->nlinks, BIF_ARG_1);

	ASSERT(pt || !l);

	if (pt) {
	    rl = erts_remove_link(&pt->nlinks, BIF_P->id);
	    erts_smp_port_unlock(pt);
	    if (rl)
		erts_destroy_link(rl);
	}

	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);

	if (l)
	    erts_destroy_link(l);

	BIF_RET(am_true);
    }
    else if (is_external_port(BIF_ARG_1)
	     && external_port_dist_entry(BIF_ARG_1) == erts_this_dist_entry) {
	BIF_RET(am_true);
    }

    if (is_not_pid(BIF_ARG_1))
	BIF_ERROR(BIF_P, BADARG);

    if (is_external_pid(BIF_ARG_1)) {
	ErtsDistLinkData dld;
	int code;
	ErtsDSigData dsd;
	/* Blind removal, we might have trapped or anything, this leaves
	   us in a state where monitors might be inconsistent, but the dist
	   code should take care of it. */
	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
#ifdef ERTS_SMP
	if (ERTS_PROC_PENDING_EXIT(BIF_P))
	    goto handle_pending_exit;
#endif
	l = erts_remove_link(&BIF_P->nlinks,BIF_ARG_1);

	erts_smp_proc_unlock(BIF_P,
			     ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);

	if (l)
	    erts_destroy_link(l);

	dep = external_pid_dist_entry(BIF_ARG_1);
	if (dep == erts_this_dist_entry) {
	    BIF_RET(am_true);
	}

	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
	switch (code) {
	case ERTS_DSIG_PREP_NOT_ALIVE:
	case ERTS_DSIG_PREP_NOT_CONNECTED:
#if 1
	    BIF_RET(am_true);
#else
	    /*
	     * This is how we used to do it, but the link is obviously not
	     * active, so I see no point in setting up a connection.
	     * /Rickard
	     */
	    BIF_TRAP1(dunlink_trap, BIF_P, BIF_ARG_1);
#endif

	case ERTS_DSIG_PREP_CONNECTED:
	    erts_remove_dist_link(&dld, BIF_P->id, BIF_ARG_1, dep);
	    code = erts_dsig_send_unlink(&dsd, BIF_P->id, BIF_ARG_1);
	    erts_destroy_dist_link(&dld);
	    if (code == ERTS_DSIG_SEND_YIELD)
		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
	    BIF_RET(am_true);

	default:
	    ASSERT(! "Invalid dsig prepare result");
	    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
	}
    }

    /* Internal pid... */

     /* process ok ? */
    if (internal_pid_index(BIF_ARG_1) >= erts_max_processes)
	BIF_ERROR(BIF_P, BADARG);

    erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);

    /* get process struct */
    rp = erts_pid2proc_opt(BIF_P, (ERTS_PROC_LOCK_MAIN
				   | ERTS_PROC_LOCK_LINK
				   | ERTS_PROC_LOCK_STATUS),
			   BIF_ARG_1, ERTS_PROC_LOCK_LINK,
			   ERTS_P2P_FLG_ALLOW_OTHER_X);

#ifdef ERTS_SMP
    if (ERTS_PROC_PENDING_EXIT(BIF_P)) {
	if (rp && rp != BIF_P)
	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
	goto handle_pending_exit;
    }
#endif

    /* unlink and ignore errors */
    l = erts_remove_link(&BIF_P->nlinks,BIF_ARG_1);
    if (l != NULL)
	erts_destroy_link(l);

    if (!rp) {
	ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
    }
    else {
	rl = erts_remove_link(&(rp->nlinks),BIF_P->id);
	if (rl != NULL)
	    erts_destroy_link(rl);

	if (IS_TRACED_FL(rp, F_TRACE_PROCS) && rl != NULL) {
	    trace_proc(BIF_P, rp, am_getting_unlinked, BIF_P->id);
	}

	if (rp != BIF_P)
	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
    }
 
    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);

    BIF_RET(am_true);

#ifdef ERTS_SMP
 handle_pending_exit:
    erts_handle_pending_exit(BIF_P, (ERTS_PROC_LOCK_MAIN
				     | ERTS_PROC_LOCK_LINK
				     | ERTS_PROC_LOCK_STATUS));
    ASSERT(ERTS_PROC_IS_EXITING(BIF_P)); 
    erts_smp_proc_unlock(BIF_P,	ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
    ERTS_BIF_EXITED(BIF_P);
#endif
}

BIF_RETTYPE hibernate_3(BIF_ALIST_3)
{
    /*
     * hibernate/3 is usually translated to an instruction; therefore
     * this function is only called from HiPE or when the call could not
     * be translated.
     */
    Eterm reg[3];

    if (erts_hibernate(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, reg)) {
        /*
         * If hibernate succeeded, TRAP. The process will be suspended
         * if status is P_WAITING or continue (if any message was in the queue).
         */
        BIF_TRAP_CODE_PTR_(BIF_P, BIF_P->i);
    }
    return THE_NON_VALUE;
}

/**********************************************************************/

BIF_RETTYPE get_stacktrace_0(Process* p)
{
    Eterm t = build_stacktrace(p, p->ftrace);
    BIF_RET(t);
}

/**********************************************************************/
/*
 * This is like exit/1, except that errors are logged if they terminate
 * the process, and the final error value will be {Term,StackTrace}.
 */

BIF_RETTYPE error_1(Process* p, Eterm term)
{
    p->fvalue = term;
    BIF_ERROR(p, EXC_ERROR);
}

/**********************************************************************/
/*
 * This is like error/1, except that the given 'args' will be included
 * in the stacktrace.
 */

BIF_RETTYPE error_2(Process* p, Eterm value, Eterm args)
{
    Eterm* hp = HAlloc(p, 3);

    p->fvalue = TUPLE2(hp, value, args);
    BIF_ERROR(p, EXC_ERROR_2);
}

/**********************************************************************/
/*
 * This is like exactly like error/1. The only difference is
 * that Dialyzer thinks that it it will return an arbitrary term.
 * It is useful in stub functions for NIFs.
 */

BIF_RETTYPE nif_error_1(Process* p, Eterm term)
{
    p->fvalue = term;
    BIF_ERROR(p, EXC_ERROR);
}

/**********************************************************************/
/*
 * This is like exactly like error/2. The only difference is
 * that Dialyzer thinks that it it will return an arbitrary term.
 * It is useful in stub functions for NIFs.
 */

BIF_RETTYPE nif_error_2(Process* p, Eterm value, Eterm args)
{
    Eterm* hp = HAlloc(p, 3);

    p->fvalue = TUPLE2(hp, value, args);
    BIF_ERROR(p, EXC_ERROR_2);
}

/**********************************************************************/
/* this is like throw/1 except that we set freason to EXC_EXIT */

BIF_RETTYPE exit_1(BIF_ALIST_1)
{
    BIF_P->fvalue = BIF_ARG_1;  /* exit value */
    BIF_ERROR(BIF_P, EXC_EXIT);
}


/**********************************************************************/
/* raise an exception of given class, value and stacktrace.
 *
 * If there is an error in the argument format, 
 * return the atom 'badarg' instead.
 */
Eterm 
raise_3(Process *c_p, Eterm class, Eterm value, Eterm stacktrace) {
    Eterm reason;
    Eterm l, *hp, *hp_end, *tp;
    int depth, cnt;
    size_t sz;
    struct StackTrace *s;
    
    if (class == am_error) {
	c_p->fvalue = value;
	reason = EXC_ERROR;
    } else if (class == am_exit) {
	c_p->fvalue = value;
	reason = EXC_EXIT;
    } else if (class == am_throw) {
	c_p->fvalue = value;
	reason = EXC_THROWN;
    } else goto error;
    reason &= ~EXF_SAVETRACE;
    
    /* Check syntax of stacktrace, and count depth.
     * Accept anything that can be returned from erlang:get_stacktrace/0,
     * as well as a 2-tuple with a fun as first element that the
     * error_handler may need to give us.
     */
    for (l = stacktrace, depth = 0;  
	 is_list(l);  
	 l = CDR(list_val(l)), depth++) {
	Eterm t = CAR(list_val(l));
	int arity;
	if (is_not_tuple(t)) goto error;
	tp = tuple_val(t);
	arity = arityval(tp[0]);
	if ((arity == 3) && is_atom(tp[1]) && is_atom(tp[2])) continue;
	if ((arity == 2) && is_fun(tp[1])) continue;
	goto error;
    }
    if (is_not_nil(l)) goto error;
    
    /* Create stacktrace and store */
    if (depth <= erts_backtrace_depth) {
	cnt = 0;
	c_p->ftrace = stacktrace;
    } else {
	cnt = depth = erts_backtrace_depth;
	c_p->ftrace = NIL;
    }
    tp = &c_p->ftrace;
    sz = (offsetof(struct StackTrace, trace) + sizeof(Eterm) - 1) 
	/ sizeof(Eterm);
    hp = HAlloc(c_p, sz + 2*(cnt + 1));
    hp_end = hp + sz + 2*(cnt + 1);
    s = (struct StackTrace *) hp;
    s->header = make_neg_bignum_header(sz - 1);
    s->freason = reason;
    s->pc = NULL;
    s->current = NULL;
    s->depth = 0;
    hp += sz;
    if (cnt > 0) {
	/* Copy list up to depth */
	for (cnt = 0, l = stacktrace;
	     cnt < depth;
	     cnt++, l = CDR(list_val(l))) {
	    ASSERT(*tp == NIL);
	    *tp = CONS(hp, CAR(list_val(l)), *tp);
	    tp = &CDR(list_val(*tp));
	    hp += 2;
	}
    }
    c_p->ftrace = CONS(hp, c_p->ftrace, make_big((Eterm *) s));
    hp += 2;
    ASSERT(hp <= hp_end);
    
    BIF_ERROR(c_p, reason);
    
 error:
    return am_badarg;
}

/**********************************************************************/
/* send an exit message to another process (if trapping exits) or
   exit the other process */

BIF_RETTYPE exit_2(BIF_ALIST_2)
{
     Process *rp;

     /*
      * If the first argument is not a pid, or a local port it is an error.
      */

     if (is_internal_port(BIF_ARG_1)) {
	 Port *prt;
	 erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	 prt = erts_id2port(BIF_ARG_1, NULL, 0);
	 if (prt) {
	     erts_do_exit_port(prt, BIF_P->id, BIF_ARG_2);
	     erts_port_release(prt);
	 }
	 erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
	 ERTS_BIF_CHK_EXITED(BIF_P);
	 BIF_RET(am_true);
     }
     else if(is_external_port(BIF_ARG_1)
	     && external_port_dist_entry(BIF_ARG_1) == erts_this_dist_entry)
	 BIF_RET(am_true);
     
     /*
      * If it is a remote pid, send a signal to the remote node.
      */

     if (is_external_pid(BIF_ARG_1)) {
	 int code;
	 ErtsDSigData dsd;
	 DistEntry *dep;

	 dep = external_pid_dist_entry(BIF_ARG_1);
	 if(dep == erts_this_dist_entry)
	     BIF_RET(am_true);

	 code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
	 switch (code) {
	 case ERTS_DSIG_PREP_NOT_ALIVE:
	 case ERTS_DSIG_PREP_NOT_CONNECTED:
	     BIF_TRAP2(dexit_trap, BIF_P, BIF_ARG_1, BIF_ARG_2);
	 case ERTS_DSIG_PREP_CONNECTED:
	     code = erts_dsig_send_exit2(&dsd, BIF_P->id, BIF_ARG_1, BIF_ARG_2);
	     if (code == ERTS_DSIG_SEND_YIELD)
		 ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
	     BIF_RET(am_true);
	 default:
	     ASSERT(! "Invalid dsig prepare result");
	     BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
	 }
     }
     else if (is_not_internal_pid(BIF_ARG_1)) {
       BIF_ERROR(BIF_P, BADARG);
     }
     else {
	 /*
	  * The pid is internal.  Verify that it refers to an existing process.
	  */
	 ErtsProcLocks rp_locks;

	 if (internal_pid_index(BIF_ARG_1) >= erts_max_processes)
	     BIF_ERROR(BIF_P, BADARG);
	 if (BIF_ARG_1 == BIF_P->id) {
	     rp_locks = ERTS_PROC_LOCKS_ALL;
	     rp = BIF_P;
	     erts_smp_proc_lock(rp, ERTS_PROC_LOCKS_ALL_MINOR);
	 }
	 else {
	     rp_locks = ERTS_PROC_LOCKS_XSIG_SEND;
	     rp = erts_pid2proc_opt(BIF_P, ERTS_PROC_LOCK_MAIN,
				    BIF_ARG_1, rp_locks,
				    ERTS_P2P_FLG_SMP_INC_REFC);
	     if (!rp) {
		 BIF_RET(am_true);
	     }
	 }

	 /*
	  * Send an exit signal.
	  */
	 erts_send_exit_signal(BIF_P,
			       BIF_P->id,
			       rp,
			       &rp_locks,
			       BIF_ARG_2,
			       NIL,
			       NULL,
			       BIF_P == rp ? ERTS_XSIG_FLG_NO_IGN_NORMAL : 0);
#ifdef ERTS_SMP
	 if (rp == BIF_P)
	     rp_locks &= ~ERTS_PROC_LOCK_MAIN;
	 if (rp_locks)
	     erts_smp_proc_unlock(rp, rp_locks);
	 if (rp != BIF_P)
	     erts_smp_proc_dec_refc(rp);
#endif
	 /*
	  * We may have exited ourselves and may have to take action.
	  */
	 ERTS_BIF_CHK_EXITED(BIF_P);
	 BIF_RET(am_true);
     }
}

/**********************************************************************/
/* this sets some process info- trapping exits or the error handler */


/* Handle flags common to both process_flag_2 and process_flag_3. */
static BIF_RETTYPE process_flag_aux(Process *BIF_P,
				    Process *rp,
				    Eterm flag,
				    Eterm val)
{
   Eterm old_value = NIL;	/* shut up warning about use before set */
   Sint i;
   if (flag == am_save_calls) {
       struct saved_calls *scb;
       if (!is_small(val))
	   goto error;
       i = signed_val(val);
       if (i < 0 || i > 10000)
	   goto error;

       if (i == 0)
	   scb = NULL;
       else {
	   Uint sz = sizeof(*scb) + (i-1) * sizeof(scb->ct[0]);
	   scb = erts_alloc(ERTS_ALC_T_CALLS_BUF, sz);
	   scb->len = i;
	   scb->cur = 0;
	   scb->n = 0;
       }

       scb = ERTS_PROC_SET_SAVED_CALLS_BUF(rp, ERTS_PROC_LOCK_MAIN, scb);

       if (!scb)
	   old_value = make_small(0);
       else {
	   old_value = make_small(scb->len);
	   erts_free(ERTS_ALC_T_CALLS_BUF, (void *) scb);
       }

       /* Make sure the process in question is rescheduled
	  immediately, if it's us, so the call saving takes effect. */
       if (rp == BIF_P)
	   BIF_RET2(old_value, CONTEXT_REDS);
       else
	   BIF_RET(old_value);
   }

 error:
   BIF_ERROR(BIF_P, BADARG);
}

BIF_RETTYPE process_flag_2(BIF_ALIST_2)
{
   Eterm old_value;
   if (BIF_ARG_1 == am_error_handler) {
      if (is_not_atom(BIF_ARG_2)) {
	 goto error;
      }
      old_value = erts_proc_set_error_handler(BIF_P,
					      ERTS_PROC_LOCK_MAIN,
					      BIF_ARG_2);
      BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_priority) {
       erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_STATUS);
       old_value = erts_set_process_priority(BIF_P, BIF_ARG_2);
       erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_STATUS);
       if (old_value == THE_NON_VALUE)
	   goto error;
       BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_trap_exit) {
       Uint trap_exit;
       if (BIF_ARG_2 == am_true) {
	   trap_exit = 1;
       } else if (BIF_ARG_2 == am_false) {
	   trap_exit = 0;
       } else {
	   goto error;
       }
       /*
	* NOTE: It is important that we check for pending exit signals
	*       and handle them before flag trap_exit is set to true.
	*       For more info, see implementation of erts_send_exit_signal().
	*/
       erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_STATUS);
       ERTS_SMP_BIF_CHK_PENDING_EXIT(BIF_P,
				     ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS);
       old_value = ERTS_PROC_IS_TRAPPING_EXITS(BIF_P) ? am_true : am_false;
       if (trap_exit) {
	   ERTS_PROC_SET_TRAP_EXIT(BIF_P);
       } else {
	   ERTS_PROC_UNSET_TRAP_EXIT(BIF_P);
       }
       erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_STATUS);
       BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_scheduler) {
       int yield;
       ErtsRunQueue *old;
       ErtsRunQueue *new;
       Sint sched;
       if (erts_common_run_queue && erts_no_schedulers > 1)
	   goto error;
       if (!is_small(BIF_ARG_2))
	   goto error;
       sched = signed_val(BIF_ARG_2);
       if (sched < 0 || erts_no_schedulers < sched)
	   goto error;
       erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_STATUS);
       old = BIF_P->bound_runq;
#ifdef ERTS_SMP
       ASSERT(!old || old == BIF_P->run_queue);
#endif
       new = !sched ? NULL : erts_schedid2runq(sched);
#ifndef ERTS_SMP
       yield = 0;
#else
       if (new == old)
	   yield = 0;
       else {
	   ErtsRunQueue *curr = BIF_P->run_queue;
	   if (!new)
	       erts_smp_runq_lock(curr);
	   else
	       erts_smp_runqs_lock(curr, new);
	   yield = new && BIF_P->run_queue != new;
#endif
	   BIF_P->bound_runq = new;
#ifdef ERTS_SMP
	   if (new)
	       BIF_P->run_queue = new;
	   if (!new)
	       erts_smp_runq_unlock(curr);
	   else
	       erts_smp_runqs_unlock(curr, new);
       }
#endif
       erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_STATUS);
       old_value = old ? make_small(old->ix+1) : make_small(0);
       if (yield)
	   ERTS_BIF_YIELD_RETURN_X(BIF_P, old_value, am_scheduler);
       else
	   BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_min_heap_size) {
       Sint i;
       if (!is_small(BIF_ARG_2)) {
	   goto error;
       }
       i = signed_val(BIF_ARG_2);
       if (i < 0) {
	   goto error;
       }
       old_value = make_small(BIF_P->min_heap_size);
       if (i < H_MIN_SIZE) {
	   BIF_P->min_heap_size = H_MIN_SIZE;
       } else {
	   BIF_P->min_heap_size = erts_next_heap_size(i, 0);
       }
       BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_min_bin_vheap_size) {
       Sint i;
       if (!is_small(BIF_ARG_2)) {
	   goto error;
       }
       i = signed_val(BIF_ARG_2);
       if (i < 0) {
	   goto error;
       }
       old_value = make_small(BIF_P->min_vheap_size);
       if (i < BIN_VH_MIN_SIZE) {
	   BIF_P->min_vheap_size = BIN_VH_MIN_SIZE;
       } else {
	   BIF_P->min_vheap_size = erts_next_heap_size(i, 0);
       }
       BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_sensitive) {
       Uint is_sensitive;
       if (BIF_ARG_2 == am_true) {
	   is_sensitive = 1;
       } else if (BIF_ARG_2 == am_false) {
	   is_sensitive = 0;
       } else {
	   goto error;
       }
       erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
       old_value = BIF_P->trace_flags & F_SENSITIVE ? am_true : am_false;
       if (is_sensitive) {
	   BIF_P->trace_flags |= F_SENSITIVE;
       } else {
	   BIF_P->trace_flags &= ~F_SENSITIVE;
       }
       erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
       BIF_RET(old_value);
   }
   else if (BIF_ARG_1 == am_monitor_nodes) {
       /*
	* This argument is intentionally *not* documented. It is intended
	* to be used by net_kernel:monitor_nodes/1.
	*/
       old_value = erts_monitor_nodes(BIF_P, BIF_ARG_2, NIL);
       if (old_value == THE_NON_VALUE)
	   goto error;
       BIF_RET(old_value);
   }
   else if (is_tuple(BIF_ARG_1)) {
       /*
	* This argument is intentionally *not* documented. It is intended
	* to be used by net_kernel:monitor_nodes/2.
	*/
       Eterm *tp = tuple_val(BIF_ARG_1);
       if (arityval(tp[0]) == 2) {
	   if (tp[1] == am_monitor_nodes) {
	       old_value = erts_monitor_nodes(BIF_P, BIF_ARG_2, tp[2]);
	       if (old_value == THE_NON_VALUE)
		   goto error;
	       BIF_RET(old_value);
	   }
       }
       /* Fall through and try process_flag_aux() ... */
   }

   BIF_RET(process_flag_aux(BIF_P, BIF_P, BIF_ARG_1, BIF_ARG_2));
 error:
   BIF_ERROR(BIF_P, BADARG);
}

BIF_RETTYPE process_flag_3(BIF_ALIST_3)
{
   Process *rp;
   Eterm res;

   if ((rp = erts_pid2proc(BIF_P, ERTS_PROC_LOCK_MAIN,
			   BIF_ARG_1, ERTS_PROC_LOCK_MAIN)) == NULL) {
       BIF_ERROR(BIF_P, BADARG);
   }

   res = process_flag_aux(BIF_P, rp, BIF_ARG_2, BIF_ARG_3);

   if (rp != BIF_P)
       erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_MAIN);

   return res;
}

/**********************************************************************/

/* register(atom, Process|Port) registers a global process or port
   (for this node) */

BIF_RETTYPE register_2(BIF_ALIST_2)   /* (Atom, Pid|Port)   */
{
    if (erts_register_name(BIF_P, BIF_ARG_1, BIF_ARG_2))
	BIF_RET(am_true);
    else {
	BIF_ERROR(BIF_P, BADARG);
    }
}


/**********************************************************************/

/* removes the registration of a process or port */

BIF_RETTYPE unregister_1(BIF_ALIST_1)
{
    int res;
    if (is_not_atom(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    res = erts_unregister_name(BIF_P, ERTS_PROC_LOCK_MAIN, NULL, BIF_ARG_1);
    if (res == 0) {
	BIF_ERROR(BIF_P, BADARG);
    }
    BIF_RET(am_true);
}

/**********************************************************************/

/* find out the pid of a registered process */
/* this is a rather unsafe BIF as it allows users to do nasty things. */

BIF_RETTYPE whereis_1(BIF_ALIST_1)
{
    Eterm res;

    if (is_not_atom(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    res = erts_whereis_name_to_id(BIF_P, BIF_ARG_1);
    BIF_RET(res);
}

/**********************************************************************/

/*
 * erlang:'!'/2
 */

Eterm
ebif_bang_2(Process* p, Eterm To, Eterm Message)
{
    return send_2(p, To, Message);
}


/*
 * Send a message to Process, Port or Registered Process.
 * Returns non-negative reduction bump or negative result code.
 */
#define SEND_TRAP		(-1)
#define SEND_YIELD		(-2)
#define SEND_YIELD_RETURN	(-3)
#define SEND_BADARG		(-4)
#define SEND_USER_ERROR		(-5)
#define SEND_INTERNAL_ERROR	(-6)

Sint do_send(Process *p, Eterm to, Eterm msg, int suspend);

static Sint remote_send(Process *p, DistEntry *dep,
			Eterm to, Eterm full_to, Eterm msg, int suspend)
{
    Sint res;
    int code;
    ErtsDSigData dsd;

    ASSERT(is_atom(to) || is_external_pid(to));

    code = erts_dsig_prepare(&dsd, dep, p, ERTS_DSP_NO_LOCK, !suspend);
    switch (code) {
    case ERTS_DSIG_PREP_NOT_ALIVE:
    case ERTS_DSIG_PREP_NOT_CONNECTED:
	res = SEND_TRAP;
	break;
    case ERTS_DSIG_PREP_WOULD_SUSPEND:
	ASSERT(!suspend);
	res = SEND_YIELD;
	break;
    case ERTS_DSIG_PREP_CONNECTED: {

	if (is_atom(to))
	    code = erts_dsig_send_reg_msg(&dsd, to, msg);
	else
	    code = erts_dsig_send_msg(&dsd, to, msg);
	/*
	 * Note that reductions have been bumped on calling
	 * process by erts_dsig_send_reg_msg() or
	 * erts_dsig_send_msg().
	 */
	if (code == ERTS_DSIG_SEND_YIELD)
	    res = SEND_YIELD_RETURN;
	else
	    res = 0;
	break;
    }
    default:
	ASSERT(! "Invalid dsig prepare result");
	res = SEND_INTERNAL_ERROR;
    }

    if (res >= 0) {
	if (IS_TRACED(p))
	    trace_send(p, full_to, msg);
	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
	    save_calls(p, &exp_send);
    }

    return res;
}

Sint
do_send(Process *p, Eterm to, Eterm msg, int suspend) {
    Eterm portid;
    Port *pt;
    Process* rp;
    DistEntry *dep;
    Eterm* tp;

    if (is_internal_pid(to)) {
	if (IS_TRACED(p))
	    trace_send(p, to, msg);
	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
	    save_calls(p, &exp_send);
	
	if (internal_pid_index(to) >= erts_max_processes)
	    return SEND_BADARG;

	rp = erts_pid2proc_opt(p, ERTS_PROC_LOCK_MAIN,
			       to, 0, ERTS_P2P_FLG_SMP_INC_REFC);
	
	if (!rp) {
	    ERTS_SMP_ASSERT_IS_NOT_EXITING(p);
	    return 0;
	}
    } else if (is_external_pid(to)) {
	dep = external_pid_dist_entry(to);
	if(dep == erts_this_dist_entry) {
	    erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
	    erts_dsprintf(dsbufp,
			  "Discarding message %T from %T to %T in an old "
			  "incarnation (%d) of this node (%d)\n",
			  msg,
			  p->id,
			  to,
			  external_pid_creation(to),
			  erts_this_node->creation);
	    erts_send_error_to_logger(p->group_leader, dsbufp);
	    return 0;
	}
	return remote_send(p, dep, to, to, msg, suspend);
    } else if (is_atom(to)) {
	
	/* Need to virtual schedule out sending process
	 * because of lock wait. This is only necessary
	 * for internal port calling but the lock is bundled
	 * with name lookup.
	 */
	    
	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    trace_virtual_sched(p, am_out);
	}
	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    profile_runnable_proc(p, am_inactive);
	}
	erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
			  to,
			  &rp, 0, ERTS_P2P_FLG_SMP_INC_REFC,
			  &pt);

	if (pt) {
	    portid = pt->id;
	    goto port_common;
	}
	
	/* Not a port virtually schedule the process back in */
	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    trace_virtual_sched(p, am_in);
	}
	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    profile_runnable_proc(p, am_active);
	}

	if (IS_TRACED(p))
	    trace_send(p, to, msg);
	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
	    save_calls(p, &exp_send);
	
	if (!rp) {
	    return SEND_BADARG;
	}
    } else if (is_external_port(to)
	       && (external_port_dist_entry(to)
		   == erts_this_dist_entry)) {
	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
	erts_dsprintf(dsbufp,
		      "Discarding message %T from %T to %T in an old "
		      "incarnation (%d) of this node (%d)\n",
		      msg,
		      p->id,
		      to,
		      external_port_creation(to),
		      erts_this_node->creation);
	erts_send_error_to_logger(p->group_leader, dsbufp);
	return 0;
    } else if (is_internal_port(to)) {
	portid = to;
	/* schedule out calling process, waiting for lock*/
	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    trace_virtual_sched(p, am_out);
	}
	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    profile_runnable_proc(p, am_inactive);
	}
	pt = erts_id2port(to, p, ERTS_PROC_LOCK_MAIN);
      port_common:
	ERTS_SMP_LC_ASSERT(!pt || erts_lc_is_port_locked(pt));
        
	/* We have waited for locks, trace schedule ports */
	if (pt && IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
	    trace_sched_ports_where(pt, am_in, am_command);
	}
	if (pt && erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
	    profile_runnable_port(pt, am_active);
	}
	
	/* XXX let port_command handle the busy stuff !!! */
	if (pt && (pt->status & ERTS_PORT_SFLG_PORT_BUSY)) {
	    if (suspend) {
		erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
		if (erts_system_monitor_flags.busy_port) {
		    monitor_generic(p, am_busy_port, portid);
		}
	    }
	    /* Virtually schedule out the port before releasing */
	    if (IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
	    	trace_sched_ports_where(pt, am_out, am_command);
	    }
	    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
	    	profile_runnable_port(pt, am_inactive);
	    }
	    erts_port_release(pt);
	    return SEND_YIELD;
	}
	
	if (IS_TRACED(p)) 	/* trace once only !! */
	    trace_send(p, portid, msg);
	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
	    save_calls(p, &exp_send);
	
	if (SEQ_TRACE_TOKEN(p) != NIL) {
	    seq_trace_update_send(p);
	    seq_trace_output(SEQ_TRACE_TOKEN(p), msg, 
			     SEQ_TRACE_SEND, portid, p);
	}	    
	
	/* XXX NO GC in port command */
	erts_port_command(p, p->id, pt, msg);
	if (pt) {
	    /* Virtually schedule out the port before releasing */
	    if (IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
	    	trace_sched_ports_where(pt, am_out, am_command);
	    }
	    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
	    	profile_runnable_port(pt, am_inactive);
	    }
	    erts_port_release(pt);
	}
	/* Virtually schedule in process */
	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    trace_virtual_sched(p, am_in);
	}
	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    profile_runnable_proc(p, am_active);
	}
	if (ERTS_PROC_IS_EXITING(p)) {
	    KILL_CATCHES(p); /* Must exit */
	    return SEND_USER_ERROR;
	}
	return 0;
    } else if (is_tuple(to)) { /* Remote send */
	int ret;
	tp = tuple_val(to);
	if (*tp != make_arityval(2))
	    return SEND_BADARG;
	if (is_not_atom(tp[1]) || is_not_atom(tp[2]))
	    return SEND_BADARG;
	
	/* sysname_to_connected_dist_entry will return NULL if there
	   is no dist_entry or the dist_entry has no port,
	   but remote_send() will handle that. */

	dep = erts_sysname_to_connected_dist_entry(tp[2]);

	if (dep == erts_this_dist_entry) {
	    erts_deref_dist_entry(dep);
	    if (IS_TRACED(p))
		trace_send(p, to, msg);
	    if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
		save_calls(p, &exp_send);
	    
	    /* Need to virtual schedule out sending process
	     * because of lock wait. This is only necessary
	     * for internal port calling but the lock is bundled.
	     */
	    
	    if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    	trace_virtual_sched(p, am_out);
	    }
	    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    	profile_runnable_proc(p, am_inactive);
	    }

	    erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
			      tp[1],
			      &rp, 0, ERTS_P2P_FLG_SMP_INC_REFC,
			      &pt);
	    if (pt) {
		portid = pt->id;
		goto port_common;
	    }
	    /* Port lookup failed, virtually schedule the process
	     * back in.
	     */

	    if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
	    	trace_virtual_sched(p, am_in);
	    }
	    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
	    	profile_runnable_proc(p, am_active);
	    }

	    if (!rp) {
		return 0;
	    }
	    goto send_message;
	}

	ret = remote_send(p, dep, tp[1], to, msg, suspend);
	if (dep)
	    erts_deref_dist_entry(dep);
	return ret;
    } else {
	if (IS_TRACED(p)) /* XXX Is this really neccessary ??? */
	    trace_send(p, to, msg);
	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
	    save_calls(p, &exp_send);
	return SEND_BADARG;
    }
    
 send_message: {
	ErtsProcLocks rp_locks = 0;
	Sint res;
#ifdef ERTS_SMP
	if (p == rp)
	    rp_locks |= ERTS_PROC_LOCK_MAIN;
#endif
	/* send to local process */
	erts_send_message(p, rp, &rp_locks, msg, 0);
	if (!erts_use_sender_punish)
	    res = 0;
	else {
#ifdef ERTS_SMP
	    res = rp->msg_inq.len*4;
	    if (ERTS_PROC_LOCK_MAIN & rp_locks)
		res += rp->msg.len*4;
#else
	    res = rp->msg.len*4;
#endif
	}
	erts_smp_proc_unlock(rp,
			     p == rp
			     ? (rp_locks & ~ERTS_PROC_LOCK_MAIN)
			     : rp_locks);
	erts_smp_proc_dec_refc(rp);
	return res;
    }
}


Eterm
send_3(Process *p, Eterm to, Eterm msg, Eterm opts) {
    int connect = !0;
    int suspend = !0;
    Eterm l = opts;
    Sint result;
    
    while (is_list(l)) {
	if (CAR(list_val(l)) == am_noconnect) {
	    connect = 0;
	} else if (CAR(list_val(l)) == am_nosuspend) {
	    suspend = 0;
	} else {
	    BIF_ERROR(p, BADARG);
	}
	l = CDR(list_val(l));
    }
    if(!is_nil(l)) {
	BIF_ERROR(p, BADARG);
    }
    
    result = do_send(p, to, msg, suspend);
    if (result > 0) {
	ERTS_VBUMP_REDS(p, result);
	BIF_RET(am_ok);
    } else switch (result) {
    case 0:
	BIF_RET(am_ok); 
	break;
    case SEND_TRAP:
	if (connect) {
	    BIF_TRAP3(dsend3_trap, p, to, msg, opts); 
	} else {
	    BIF_RET(am_noconnect);
	}
	break;
    case SEND_YIELD:
	if (suspend) {
	    ERTS_BIF_YIELD3(bif_export[BIF_send_3], p, to, msg, opts);
	} else {
	    BIF_RET(am_nosuspend);
	}
	break;
    case SEND_YIELD_RETURN:
	if (suspend)
	    ERTS_BIF_YIELD_RETURN(p, am_ok);
	else
	    BIF_RET(am_nosuspend);
    case SEND_BADARG:
	BIF_ERROR(p, BADARG); 
	break;
    case SEND_USER_ERROR:
	BIF_ERROR(p, EXC_ERROR); 
	break;
    case SEND_INTERNAL_ERROR:
	BIF_ERROR(p, EXC_INTERNAL_ERROR);
	break;
    default:
	ASSERT(! "Illegal send result"); 
	break;
    }
    ASSERT(! "Can not arrive here");
    BIF_ERROR(p, BADARG);
}

Eterm
send_2(Process *p, Eterm to, Eterm msg) {
    Sint result = do_send(p, to, msg, !0);
    
    if (result > 0) {
	ERTS_VBUMP_REDS(p, result);
	BIF_RET(msg);
    } else switch (result) {
    case 0:
	BIF_RET(msg); 
	break;
    case SEND_TRAP:
	BIF_TRAP2(dsend2_trap, p, to, msg); 
	break;
    case SEND_YIELD:
	ERTS_BIF_YIELD2(bif_export[BIF_send_2], p, to, msg);
	break;
    case SEND_YIELD_RETURN:
	ERTS_BIF_YIELD_RETURN(p, msg);
    case SEND_BADARG:
	BIF_ERROR(p, BADARG); 
	break;
    case SEND_USER_ERROR:
	BIF_ERROR(p, EXC_ERROR); 
	break;
    case SEND_INTERNAL_ERROR:
	BIF_ERROR(p, EXC_INTERNAL_ERROR);
	break;
    default:
	ASSERT(! "Illegal send result"); 
	break;
    }
    ASSERT(! "Can not arrive here");
    BIF_ERROR(p, BADARG);
}

/**********************************************************************/
/*
 * apply/3 is implemented as an instruction and as erlang code in the
 * erlang module.
 *
 * There is only one reason that apply/3 is included in the BIF table:
 * The error handling code in the beam emulator passes the pointer to
 * this function to the error handling code if the apply instruction
 * fails.  The error handling use the function pointer to lookup
 * erlang:apply/3 in the BIF table.
 *
 * This function will never be called.  (It could be if init did something
 * like this:  apply(erlang, apply, [M, F, A]). Not recommended.)
 */

BIF_RETTYPE apply_3(BIF_ALIST_3)
{
    BIF_ERROR(BIF_P, BADARG);
}


/**********************************************************************/

/* integer to float */

/**********************************************************************/

/* returns the head of a list - this function is unecessary
   and is only here to keep Robert happy (Even more, since it's OP as well) */
BIF_RETTYPE hd_1(BIF_ALIST_1)
{
     if (is_not_list(BIF_ARG_1)) {
	 BIF_ERROR(BIF_P, BADARG);
     }
     BIF_RET(CAR(list_val(BIF_ARG_1)));
}

/**********************************************************************/

/* returns the tails of a list - same comment as above */

BIF_RETTYPE tl_1(BIF_ALIST_1)
{
    if (is_not_list(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    BIF_RET(CDR(list_val(BIF_ARG_1)));
}


/**********************************************************************/
/* return the size of an I/O list */

BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
{
    Sint size = io_list_len(BIF_ARG_1);

    if (size == -1) {
	BIF_ERROR(BIF_P, BADARG);
    } else if (IS_USMALL(0, (Uint) size)) {
	BIF_RET(make_small(size));
    } else {
	Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
	BIF_RET(uint_to_big(size, hp));
    }
}


/**********************************************************************/

/* return the N'th element of a tuple */

BIF_RETTYPE element_2(BIF_ALIST_2)
{
    if (is_not_small(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    if (is_tuple(BIF_ARG_2)) {
	Eterm* tuple_ptr = tuple_val(BIF_ARG_2);
	Sint ix = signed_val(BIF_ARG_1);

	if ((ix >= 1) && (ix <= arityval(*tuple_ptr)))
	    BIF_RET(tuple_ptr[ix]);
    }
    BIF_ERROR(BIF_P, BADARG);
}

/**********************************************************************/

/* return the arity of a tuple */

BIF_RETTYPE tuple_size_1(BIF_ALIST_1)
{
    if (is_tuple(BIF_ARG_1)) {
	return make_small(arityval(*tuple_val(BIF_ARG_1)));
    }
    BIF_ERROR(BIF_P, BADARG);
}

/**********************************************************************/

/* set the n'th element in a tuple */

BIF_RETTYPE setelement_3(BIF_ALIST_3)
{
    Eterm* ptr;
    Eterm* hp;
    Eterm* resp;
    Uint ix;
    Uint size;

    if (is_not_small(BIF_ARG_1) || is_not_tuple(BIF_ARG_2)) {
    error:
	BIF_ERROR(BIF_P, BADARG);
    }
    ptr = tuple_val(BIF_ARG_2);
    ix = signed_val(BIF_ARG_1);
    size = arityval(*ptr) + 1;   /* include arity */
    if ((ix < 1) || (ix >= size)) {
	goto error;
    }

    hp = HAlloc(BIF_P, size);

    /* copy the tuple */
    resp = hp;
    while (size--) {		/* XXX use memcpy? */
	*hp++ = *ptr++;
    }
    resp[ix] = BIF_ARG_3;
    BIF_RET(make_tuple(resp));
}

/**********************************************************************/

BIF_RETTYPE make_tuple_2(BIF_ALIST_2)
{
    Sint n;
    Eterm* hp;
    Eterm res;

    if (is_not_small(BIF_ARG_1) || (n = signed_val(BIF_ARG_1)) < 0) {
	BIF_ERROR(BIF_P, BADARG);
    }
    hp = HAlloc(BIF_P, n+1);
    res = make_tuple(hp);
    *hp++ = make_arityval(n);
    while (n--) {
	*hp++ = BIF_ARG_2;
    }
    BIF_RET(res);
}

BIF_RETTYPE make_tuple_3(BIF_ALIST_3)
{
    Sint n;
    Uint limit;
    Eterm* hp;
    Eterm res;
    Eterm list = BIF_ARG_3;
    Eterm* tup;

    if (is_not_small(BIF_ARG_1) || (n = signed_val(BIF_ARG_1)) < 0) {
    error:
	BIF_ERROR(BIF_P, BADARG);
    }
    limit = (Uint) n;
    hp = HAlloc(BIF_P, n+1);
    res = make_tuple(hp);
    *hp++ = make_arityval(n);
    tup = hp;
    while (n--) {
	*hp++ = BIF_ARG_2;
    }
    while(is_list(list)) {
	Eterm* cons;
	Eterm hd;
	Eterm* tp;
	Eterm index;
	Uint index_val;

	cons = list_val(list);
	hd = CAR(cons);
	list = CDR(cons);
	if (is_not_tuple_arity(hd, 2)) {
	    goto error;
	}
	tp = tuple_val(hd);
	if (is_not_small(index = tp[1])) {
	    goto error;
	}
	if ((index_val = unsigned_val(index) - 1) < limit) {
	    tup[index_val] = tp[2];
	} else {
	    goto error;
	}
    }
    if (is_not_nil(list)) {
	goto error;
    }
    BIF_RET(res);
}


/**********************************************************************/

BIF_RETTYPE append_element_2(BIF_ALIST_2)
{
    Eterm* ptr;
    Eterm* hp;
    Uint arity;
    Eterm res;

    if (is_not_tuple(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    ptr = tuple_val(BIF_ARG_1);
    arity = arityval(*ptr);
    hp = HAlloc(BIF_P, arity + 2);
    res = make_tuple(hp);
    *hp = make_arityval(arity+1);
    while (arity--) {
	*++hp = *++ptr;
    }
    *++hp = BIF_ARG_2;
    BIF_RET(res);
}

/**********************************************************************/

/* convert an atom to a list of ascii integer */

BIF_RETTYPE atom_to_list_1(BIF_ALIST_1)
{
    Uint need;
    Eterm* hp;
    Atom* ap;

    if (is_not_atom(BIF_ARG_1))
	BIF_ERROR(BIF_P, BADARG);
     
    /* read data from atom table */
    ap = atom_tab(atom_val(BIF_ARG_1));
    if (ap->len == 0)
	BIF_RET(NIL);	/* the empty atom */
    need = ap->len*2;
    hp = HAlloc(BIF_P, need);
    BIF_RET(buf_to_intlist(&hp,(char*)ap->name,ap->len, NIL));
}

/**********************************************************************/

/* convert a list of ascii integers to an atom */
 
BIF_RETTYPE list_to_atom_1(BIF_ALIST_1)
{
    Eterm res;
    char *buf = (char *) erts_alloc(ERTS_ALC_T_TMP, MAX_ATOM_LENGTH);
    int i = intlist_to_buf(BIF_ARG_1, buf, MAX_ATOM_LENGTH);

    if (i < 0) {
	erts_free(ERTS_ALC_T_TMP, (void *) buf);
	i = list_length(BIF_ARG_1);
	if (i > MAX_ATOM_LENGTH) {
	    BIF_ERROR(BIF_P, SYSTEM_LIMIT);
	}
	BIF_ERROR(BIF_P, BADARG);
    }
    res = am_atom_put(buf, i);
    erts_free(ERTS_ALC_T_TMP, (void *) buf);
    BIF_RET(res);
}

/* conditionally convert a list of ascii integers to an atom */
 
BIF_RETTYPE list_to_existing_atom_1(BIF_ALIST_1)
{
    int i;
    char *buf = (char *) erts_alloc(ERTS_ALC_T_TMP, MAX_ATOM_LENGTH);

    if ((i = intlist_to_buf(BIF_ARG_1, buf, MAX_ATOM_LENGTH)) < 0) {
    error:
	erts_free(ERTS_ALC_T_TMP, (void *) buf);
	BIF_ERROR(BIF_P, BADARG);
    } else {
	Eterm a;
	
	if (erts_atom_get(buf, i, &a)) {
	    erts_free(ERTS_ALC_T_TMP, (void *) buf);
	    BIF_RET(a);
	} else {
	    goto error;
	}
    }
}


/**********************************************************************/

/* convert an integer to a list of ascii integers */

BIF_RETTYPE integer_to_list_1(BIF_ALIST_1)
{
    Eterm* hp;
    Uint need;

    if (is_not_integer(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }

    if (is_small(BIF_ARG_1)) {
	char *c;
	int n;
	struct Sint_buf ibuf;

	c = Sint_to_buf(signed_val(BIF_ARG_1), &ibuf);
	n = sys_strlen(c);
	need = 2*n;
	hp = HAlloc(BIF_P, need);
	BIF_RET(buf_to_intlist(&hp, c, n, NIL));
    }
    else {
	int n = big_decimal_estimate(BIF_ARG_1);
	Eterm res;
        Eterm* hp_end;

	need = 2*n;
	hp = HAlloc(BIF_P, need);
        hp_end = hp + need;
	res = erts_big_to_list(BIF_ARG_1, &hp);
        HRelease(BIF_P,hp_end,hp);
	BIF_RET(res);
    }
}

/**********************************************************************/

/* convert a list of ascii ascii integer value to an integer */


#define LTI_BAD_STRUCTURE 0
#define LTI_NO_INTEGER 1
#define LTI_SOME_INTEGER 2
#define LTI_ALL_INTEGER 3

static int do_list_to_integer(Process *p, Eterm orig_list, 
			      Eterm *integer, Eterm *rest)
{
     Sint i = 0;
     int skip = 0;
     int neg = 0;
     int n = 0;
     int m;
     int lg2;
     Eterm res;
     Eterm* hp;
     Eterm *hp_end;
     Eterm lst = orig_list;
     Eterm tail = lst;
     int error_res = LTI_BAD_STRUCTURE;

     if (is_nil(lst)) {
       error_res = LTI_NO_INTEGER;
     error:
	 *rest = tail;
	 *integer = make_small(0);
	 return error_res;
     }       
     if (is_not_list(lst))
       goto error;

     /* if first char is a '-' then it is a negative integer */
     if (CAR(list_val(lst)) == make_small('-')) {
	  neg = 1;
	  skip = 1;
	  lst = CDR(list_val(lst));
	  if (is_not_list(lst)) {
	      tail = lst;
	      error_res = LTI_NO_INTEGER;
	      goto error;
	  }
     } else if (CAR(list_val(lst)) == make_small('+')) {
	 /* ignore plus */
	 skip = 1;
	 lst = CDR(list_val(lst));
	 if (is_not_list(lst)) {
	     tail = lst;
	     error_res = LTI_NO_INTEGER;
	     goto error;
	 }
     }

     /* Calculate size and do type check */

     while(1) {
	 if (is_not_small(CAR(list_val(lst)))) {
	     break;
	 }
	 if (unsigned_val(CAR(list_val(lst))) < '0' ||
	     unsigned_val(CAR(list_val(lst))) > '9') {
	     break;
	 }
	 i = i * 10;
	 i = i + unsigned_val(CAR(list_val(lst))) - '0';
	 n++;
	 lst = CDR(list_val(lst));
	 if (is_nil(lst)) {
	     break;
	 }
	 if (is_not_list(lst)) {
	     break;
	 }
     }

     tail = lst;
     if (!n) {
	 error_res = LTI_NO_INTEGER;
	 goto error;
     } 

	 
      /* If n <= 8 then we know it's a small int 
      ** since 2^27 = 134217728. If n > 8 then we must
      ** construct a bignum and let that routine do the checking
      */

     if (n <= SMALL_DIGITS) {  /* It must be small */
	 if (neg) i = -i;
	 res = make_small(i);
     } else {
	 lg2 =  (n+1)*230/69+1;
	 m  = (lg2+D_EXP-1)/D_EXP; /* number of digits */
	 m  = BIG_NEED_SIZE(m);    /* number of words + thing */

	 hp = HAlloc(p, m);
	 hp_end = hp + m;
	 
	 lst = orig_list;
	 if (skip)
	     lst = CDR(list_val(lst));
	 
	 /* load first digits (at least one digit) */
	 if ((i = (n % D_DECIMAL_EXP)) == 0)
	     i = D_DECIMAL_EXP;
	 n -= i;
	 m = 0;
	 while(i--) {
	     m = 10*m + (unsigned_val(CAR(list_val(lst))) - '0');
	     lst = CDR(list_val(lst));
	 }
	 res = small_to_big(m, hp);  /* load first digits */
	 
	 while(n) {
	     i = D_DECIMAL_EXP;
	     n -= D_DECIMAL_EXP;
	     m = 0;
	     while(i--) {
		 m = 10*m + (unsigned_val(CAR(list_val(lst))) - '0');
		 lst = CDR(list_val(lst));
	     }
	     if (is_small(res))
		 res = small_to_big(signed_val(res), hp);
	     res = big_times_small(res, D_DECIMAL_BASE, hp);
	     if (is_small(res))
		 res = small_to_big(signed_val(res), hp);
	     res = big_plus_small(res, m, hp);
	 }

	 if (is_big(res))  /* check if small */
	     res = big_plus_small(res, 0, hp); /* includes conversion to small */
	 
	 if (neg) {
	     if (is_small(res))
		 res = make_small(-signed_val(res));
	     else {
		 Uint *big = big_val(res); /* point to thing */
		 *big = bignum_header_neg(*big);
	     }
	 }

	 if (is_big(res)) {
	     hp += (big_arity(res)+1);
	 }
	 HRelease(p,hp_end,hp);
     }
     *integer = res;
     *rest = tail;
     if (tail != NIL) {
	 return LTI_SOME_INTEGER;
     }
     return LTI_ALL_INTEGER;
}
BIF_RETTYPE string_to_integer_1(BIF_ALIST_1)
{
     Eterm res;
     Eterm tail;
     Eterm *hp;
     /* must be a list */
     switch (do_list_to_integer(BIF_P,BIF_ARG_1,&res,&tail)) {
	 /* HAlloc after do_list_to_integer as it 
	    might HAlloc itself (bignum) */
     case LTI_BAD_STRUCTURE:
	 hp = HAlloc(BIF_P,3);
	 BIF_RET(TUPLE2(hp, am_error, am_not_a_list));
     case LTI_NO_INTEGER:
	 hp = HAlloc(BIF_P,3);
	 BIF_RET(TUPLE2(hp, am_error, am_no_integer));
     default:
	 hp = HAlloc(BIF_P,3);
	 BIF_RET(TUPLE2(hp, res, tail));
     }
}
								 

BIF_RETTYPE list_to_integer_1(BIF_ALIST_1)
{
     Eterm res;
     Eterm dummy;
     /* must be a list */
     
     if (do_list_to_integer(BIF_P,BIF_ARG_1,&res,&dummy) != LTI_ALL_INTEGER) {
	 BIF_ERROR(BIF_P,BADARG);
     }
     BIF_RET(res);
 }

/**********************************************************************/

/* convert a float to a list of ascii characters */

BIF_RETTYPE float_to_list_1(BIF_ALIST_1)
{
     int i;
     Uint need;
     Eterm* hp;
     FloatDef f;
     char fbuf[30];
     
     /* check the arguments */
     if (is_not_float(BIF_ARG_1))
	 BIF_ERROR(BIF_P, BADARG);
     GET_DOUBLE(BIF_ARG_1, f);
     if ((i = sys_double_to_chars(f.fd, fbuf)) <= 0)
	 BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
     need = i*2;
     hp = HAlloc(BIF_P, need);
     BIF_RET(buf_to_intlist(&hp, fbuf, i, NIL));
 }

/**********************************************************************/

/* convert a list of ascii  integer values e's +'s and -'s to a float */


#define SIGN      0
#define INT       1
#define FRAC      2
#define EXP_SIGN  3
#define EXP0      4
#define EXP1      5
#define END       6

#define IS_DOT(x) (unsigned_val((x)) == '.' || unsigned_val((x)) == ',')
#define IS_E(x) (unsigned_val((x)) == 'e' || unsigned_val((x)) == 'E')
#define IS_DIGIT(x) (unsigned_val((x)) >= '0' && unsigned_val((x)) <= '9')
#define SAVE_E(xi,xim,xl,xlm) ((xim)=(xi), (xlm)=(xl))
#define LOAD_E(xi,xim,xl,xlm) ((xi)=(xim), (xl)=(xlm))

#define STRING_TO_FLOAT_BUF_INC_SZ (128)
BIF_RETTYPE string_to_float_1(BIF_ALIST_1)
{
    Eterm orig = BIF_ARG_1;
    Eterm list = orig;
    Eterm list_mem = list;
    int i = 0;
    int i_mem = 0;
    Eterm* hp;
    Eterm error_res = NIL;
    int part = SIGN;	/* expect a + or - (or a digit) first */
    FloatDef f;
    Eterm tup;
    byte *buf = NULL;
    Uint bufsz = STRING_TO_FLOAT_BUF_INC_SZ;

    /* check it's a valid list to start with */
    if (is_nil(list)) {
	error_res = am_no_float;
    error:
	if (buf)
	    erts_free(ERTS_ALC_T_TMP, (void *) buf);
	hp = HAlloc(BIF_P, 3);    
	BIF_RET(TUPLE2(hp, am_error, error_res));
    }
    if (is_not_list(list)) {
	error_res = am_not_a_list;
	goto error;
    }

    buf = (byte *) erts_alloc(ERTS_ALC_T_TMP, bufsz);

    /*
       The float might start with a SIGN (+ | -). It must contain an integer 
       part, INT, followed by a delimiter (. | ,) and a fractional, FRAC, 
       part. The float might also contain an exponent. If e or E indicates 
       this we will look for a possible EXP_SIGN (+ | -) followed by the
       exponential number, EXP. (EXP0 is the first digit and EXP1 the rest).

       When we encounter an expected e or E, we can't tell if it's part of
       the float or the rest of the string. We save the current position 
       with SAVE_E. If we later find out it was not part of the float, we
       restore the position (end of the float) with LOAD_E.
    */
    while(1) {
	if (is_not_small(CAR(list_val(list)))) 
	    goto back_to_e;
	if (CAR(list_val(list)) == make_small('-')) {
	    switch (part) {
	    case SIGN:		/* expect integer part next */
		part = INT;		
		break;
	    case EXP_SIGN:	/* expect first digit in exp */
		part = EXP0;
		break;
	    case EXP0:		/* example: "2.3e--" */
		LOAD_E(i, i_mem, list, list_mem);
	    default:		/* unexpected - done */
		part = END;
	    }
	} else if (CAR(list_val(list)) == make_small('+')) {
	    switch (part) {
	    case SIGN:		/* expect integer part next */
		part = INT;
		goto skip;
	    case EXP_SIGN:	/* expect first digit in exp */
		part = EXP0;
		break;
	    case EXP0:		/* example: "2.3e++" */
		LOAD_E(i, i_mem, list, list_mem);
	    default:		/* unexpected - done */
		part = END;
	    }
	} else if (IS_DOT(CAR(list_val(list)))) { /* . or , */
	    switch (part) {
	    case INT:		/* expect fractional part next */
		part = FRAC;
		break;
	    case EXP_SIGN:	/* example: "2.3e." */
		LOAD_E(i, i_mem, list, list_mem);
	    case EXP0:		/* example: "2.3e+." */
		LOAD_E(i, i_mem, list, list_mem);
	    default:		/* unexpected - done */
		part = END;
	    }
	} else if (IS_E(CAR(list_val(list)))) {	/* e or E */
	    switch (part) {
	    case FRAC:		/* expect a + or - (or a digit) next */
		/* 
		   remember the position of e in case we find out later
		   that it was not part of the float, e.g. "2.3eh?" 
		*/
		SAVE_E(i, i_mem, list, list_mem);
		part = EXP_SIGN;
		break;
	    case EXP0:		/* example: "2.3e+e" */
	    case EXP_SIGN:	/* example: "2.3ee" */
		LOAD_E(i, i_mem, list, list_mem);
	    case INT:		/* would like this to be ok, example "2e2",
				   but it's not compatible with list_to_float */
	    default:		/* unexpected - done */
		part = END;
	    }
	} else if (IS_DIGIT(CAR(list_val(list)))) { /* digit */
	    switch (part) {
	    case SIGN:		/* got initial digit in integer part */
		part = INT;	/* expect more digits to follow */
		break;
	    case EXP_SIGN:	/* expect exponential part */
	    case EXP0:		/* expect rest of exponential */
		part = EXP1;
		break;
	    }
	} else			/* character not part of float - done */
	    goto back_to_e;
	
	if (part == END) {
	    if (i < 3) {	/* we require a fractional part */
		error_res = am_no_float;
		goto error;
	    }
	    break;
	}

	buf[i++] = unsigned_val(CAR(list_val(list)));

	if (i == bufsz - 1)
	    buf = (byte *) erts_realloc(ERTS_ALC_T_TMP,
					(void *) buf,
					bufsz += STRING_TO_FLOAT_BUF_INC_SZ);
    skip:
	list = CDR(list_val(list)); /* next element */

	if (is_nil(list))
	    goto back_to_e;

	if (is_not_list(list)) {
	back_to_e:
	    if (part == EXP_SIGN || part == EXP0) {
		LOAD_E(i, i_mem, list, list_mem);
	    }
	    break;
	}
    }
      
    if (i == 0) {		/* no float first in list */
	error_res = am_no_float;
	goto error;
    }

    buf[i] = '\0';		/* null terminal */
    ASSERT(bufsz >= i + 1);
    if (sys_chars_to_double((char*) buf, &f.fd) != 0) {
	error_res = am_no_float;
	goto error;
    }
    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT + 3);
    tup = TUPLE2(hp+FLOAT_SIZE_OBJECT, make_float(hp), list);
    PUT_DOUBLE(f, hp);
    erts_free(ERTS_ALC_T_TMP, (void *) buf);
    BIF_RET(tup);
}


BIF_RETTYPE list_to_float_1(BIF_ALIST_1)
{
    int i;
    FloatDef f;
    Eterm res;
    Eterm* hp;
    char *buf = NULL;

    i = list_length(BIF_ARG_1);
    if (i < 0) {
    badarg:
	if (buf)
	    erts_free(ERTS_ALC_T_TMP, (void *) buf);
	BIF_ERROR(BIF_P, BADARG);
    }

    buf = (char *) erts_alloc(ERTS_ALC_T_TMP, i + 1);
    
    if (intlist_to_buf(BIF_ARG_1, buf, i) < 0)
	goto badarg;
    buf[i] = '\0';		/* null terminal */

    if (sys_chars_to_double(buf, &f.fd) != 0)
	goto badarg;
    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
    res = make_float(hp);
    PUT_DOUBLE(f, hp);
    erts_free(ERTS_ALC_T_TMP, (void *) buf);
    BIF_RET(res);
}

/**********************************************************************/

/* convert a tuple to a list */

BIF_RETTYPE tuple_to_list_1(BIF_ALIST_1)
{
    Uint n;
    Eterm *tupleptr;
    Eterm list = NIL;
    Eterm* hp;

    if (is_not_tuple(BIF_ARG_1))  {
	BIF_ERROR(BIF_P, BADARG);
    }

    tupleptr = tuple_val(BIF_ARG_1);
    n = arityval(*tupleptr);
    hp = HAlloc(BIF_P, 2 * n);
    tupleptr++;

    while(n--) {
	list = CONS(hp, tupleptr[n], list);
	hp += 2;
    }
    BIF_RET(list);
}

/**********************************************************************/

/* convert a list to a tuple */

BIF_RETTYPE list_to_tuple_1(BIF_ALIST_1)
{
    Eterm list = BIF_ARG_1;
    Eterm* cons;
    Eterm res;
    Eterm* hp;
    int len;

    if ((len = list_length(list)) < 0) {
	BIF_ERROR(BIF_P, BADARG);
    }

    hp = HAlloc(BIF_P, len+1);
    res = make_tuple(hp);
    *hp++ = make_arityval(len);
    while(is_list(list)) {
	cons = list_val(list);
	*hp++ = CAR(cons);
	list = CDR(cons);
    }
    BIF_RET(res);
}

/**********************************************************************/

/* return the pid of our own process, in most cases this has been replaced by
   a machine instruction */

BIF_RETTYPE self_0(BIF_ALIST_0)
{
     BIF_RET(BIF_P->id);
}

/**********************************************************************/

/*
   New representation of refs in R9, see erl_term.h

   In the first data word, only the usual 18 bits are used. Ordinarily,
   in "long refs" all words are used (in other words, practically never
   wrap around), but for compatibility with older nodes, "short refs"
   exist. Short refs come into being by being converted from the old
   external format for refs (tag REFERENCE_EXT). Short refs are
   converted back to the old external format.

   When converting a long ref to the external format in the case of
   preparing for sending to an older node, the ref is truncated by only
   using the first word (with 18 significant bits), and using the old tag
   REFERENCE_EXT.

   When comparing refs or different size, only the parts up to the length
   of the shorter operand are used. This has the desirable effect that a
   long ref sent to an old node and back will be treated as equal to
   the original, although some of the bits have been lost.

   The hash value for a ref always considers only the first word, since
   in the above scenario, the original and the copy should have the same
   hash value.
*/

static Uint32 reference0; /* Initialized in erts_init_bif */
static Uint32 reference1;
static Uint32 reference2;
static erts_smp_spinlock_t make_ref_lock;
static erts_smp_mtx_t ports_snapshot_mtx;
erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */

Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
{
    Eterm* hp = buffer;
    Uint32 ref0, ref1, ref2;

    erts_smp_spin_lock(&make_ref_lock);

    reference0++;
    if (reference0 >= MAX_REFERENCE) {
	reference0 = 0;
	reference1++;
	if (reference1 == 0) {
	    reference2++;
	}
    }

    ref0 = reference0;
    ref1 = reference1;
    ref2 = reference2;

    erts_smp_spin_unlock(&make_ref_lock);

    write_ref_thing(hp, ref0, ref1, ref2);
    return make_internal_ref(hp);
}

Eterm erts_make_ref(Process *p)
{
    Eterm* hp;

    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p));

    hp = HAlloc(p, REF_THING_SIZE);
    return erts_make_ref_in_buffer(hp);
}

BIF_RETTYPE make_ref_0(BIF_ALIST_0)
{
    return erts_make_ref(BIF_P);
}

/**********************************************************************/

/* return the time of day */

BIF_RETTYPE time_0(BIF_ALIST_0)
{
     int hour, minute, second;
     Eterm* hp;

     get_time(&hour, &minute, &second);
     hp = HAlloc(BIF_P, 4);	/* {hour, minute, second}  + arity */
     BIF_RET(TUPLE3(hp, make_small(hour), make_small(minute),
		    make_small(second)));
}
/**********************************************************************/

/* return the date */

BIF_RETTYPE date_0(BIF_ALIST_0)
{
     int year, month, day;
     Eterm* hp;
     
     get_date(&year, &month, &day);
     hp = HAlloc(BIF_P, 4);	/* {year, month, day}  + arity */
     BIF_RET(TUPLE3(hp, make_small(year), make_small(month), make_small(day)));
}

/**********************************************************************/

/* return the universal time */

BIF_RETTYPE universaltime_0(BIF_ALIST_0)
{
     int year, month, day;
     int hour, minute, second;
     Eterm res1, res2;
     Eterm* hp;

     /* read the clock */
     get_universaltime(&year, &month, &day, &hour, &minute, &second);

     hp = HAlloc(BIF_P, 4+4+3);

     /* and return the tuple */
     res1 = TUPLE3(hp,make_small(year),make_small(month),make_small(day));
     hp += 4;
     res2 = TUPLE3(hp,make_small(hour),make_small(minute),make_small(second));
     hp += 4;
     BIF_RET(TUPLE2(hp, res1, res2));
 }

/**********************************************************************/

/* return the universal time */

BIF_RETTYPE localtime_0(BIF_ALIST_0)
{
     int year, month, day;
     int hour, minute, second;
     Eterm res1, res2;
     Eterm* hp;

     /* read the clock */
     get_localtime(&year, &month, &day, &hour, &minute, &second);

     hp = HAlloc(BIF_P, 4+4+3);

     /* and return the tuple */
     res1 = TUPLE3(hp,make_small(year),make_small(month),make_small(day));
     hp += 4;
     res2 = TUPLE3(hp,make_small(hour),make_small(minute),make_small(second));
     hp += 4;
     BIF_RET(TUPLE2(hp, res1, res2));
}
/**********************************************************************/

/* type check and extract components from a tuple on form: {{Y,M,D},{H,M,S}} */
static int 
time_to_parts(Eterm date, Sint* year, Sint* month, Sint* day,
	      Sint* hour, Sint* minute, Sint* second)
{
    Eterm* t1;
    Eterm* t2;

    if (is_not_tuple(date)) {
	return 0;
    }
    t1 = tuple_val(date);
    if (arityval(t1[0]) !=2 || 
	is_not_tuple(t1[1]) || is_not_tuple(t1[2]))
	return 0;
    t2 = tuple_val(t1[1]);
    t1 = tuple_val(t1[2]);
    if (arityval(t2[0]) != 3 || 
	is_not_small(t2[1]) || is_not_small(t2[2]) || is_not_small(t2[3]))
	return 0;
    *year  = signed_val(t2[1]);
    *month = signed_val(t2[2]);
    *day   = signed_val(t2[3]);
    if (arityval(t1[0]) != 3 || 
	is_not_small(t1[1]) || is_not_small(t1[2]) || is_not_small(t1[3]))
	return 0;
    *hour   = signed_val(t1[1]);
    *minute = signed_val(t1[2]);
    *second = signed_val(t1[3]);
    return 1;
}


/* return the universal time */

BIF_RETTYPE 
localtime_to_universaltime_2(Process *p, Eterm localtime, Eterm dst)
{
    Sint year, month, day;
    Sint hour, minute, second;
    int isdst;
    Eterm res1, res2;
    Eterm* hp;
    
    if (dst == am_true) isdst = 1;
    else if (dst == am_false) isdst = 0;
    else if (dst == am_undefined) isdst = -1;
    else goto error;
    
    if (!time_to_parts(localtime, &year, &month, &day, 
		       &hour, &minute, &second)) goto error;
    if (!local_to_univ(&year, &month, &day, 
		       &hour, &minute, &second, isdst)) goto error;
    
    hp = HAlloc(p, 4+4+3);
    res1 = TUPLE3(hp,make_small(year),make_small(month),
		  make_small(day));
    hp += 4;
    res2 = TUPLE3(hp,make_small(hour),make_small(minute),
		  make_small(second));
    hp += 4;
    BIF_RET(TUPLE2(hp, res1, res2));
 error:
    BIF_ERROR(p, BADARG);
 }
	 

/**********************************************************************/

/* return the universal time */

BIF_RETTYPE universaltime_to_localtime_1(BIF_ALIST_1)
{
    Sint year, month, day;
    Sint hour, minute, second;
    Eterm res1, res2;
    Eterm* hp;

    if (!time_to_parts(BIF_ARG_1, &year, &month, &day, 
		       &hour, &minute, &second))
	BIF_ERROR(BIF_P, BADARG);
    if (!univ_to_local(&year, &month, &day, 
		       &hour, &minute, &second))
	BIF_ERROR(BIF_P, BADARG);
    
    hp = HAlloc(BIF_P, 4+4+3);
    res1 = TUPLE3(hp,make_small(year),make_small(month),
		  make_small(day));
    hp += 4;
    res2 = TUPLE3(hp,make_small(hour),make_small(minute),
		  make_small(second));
    hp += 4;
    BIF_RET(TUPLE2(hp, res1, res2));
}

/**********************************************************************/


 /* return a timestamp */
BIF_RETTYPE now_0(BIF_ALIST_0)
{
    Uint megasec, sec, microsec;
    Eterm* hp;

    get_now(&megasec, &sec, &microsec);
    hp = HAlloc(BIF_P, 4);
    BIF_RET(TUPLE3(hp, make_small(megasec), make_small(sec),
		   make_small(microsec)));
}

/**********************************************************************/

BIF_RETTYPE garbage_collect_1(BIF_ALIST_1)
{
    int reds;
    Process *rp;

    if (is_not_pid(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }

    rp = erts_pid2proc_not_running(BIF_P, ERTS_PROC_LOCK_MAIN,
				   BIF_ARG_1, ERTS_PROC_LOCK_MAIN);
    if (!rp)
	BIF_RET(am_false);
    if (rp == ERTS_PROC_LOCK_BUSY)
	ERTS_BIF_YIELD1(bif_export[BIF_garbage_collect_1], BIF_P, BIF_ARG_1);

    /* The GC cost is taken for the process executing this BIF. */

    FLAGS(rp) |= F_NEED_FULLSWEEP;
    reds = erts_garbage_collect(rp, 0, rp->arg_reg, rp->arity);

    if (BIF_P != rp)
	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_MAIN);

    BIF_RET2(am_true, reds);
}

BIF_RETTYPE garbage_collect_0(BIF_ALIST_0)
{
    int reds;

    FLAGS(BIF_P) |= F_NEED_FULLSWEEP;
    reds = erts_garbage_collect(BIF_P, 0, NULL, 0);
    BIF_RET2(am_true, reds);
}

/**********************************************************************/
/* Perform garbage collection of the message area */

BIF_RETTYPE garbage_collect_message_area_0(BIF_ALIST_0)
{
#if defined(HYBRID) && !defined(INCREMENTAL)
    int reds = 0;

    FLAGS(BIF_P) |= F_NEED_FULLSWEEP;
    reds = erts_global_garbage_collect(BIF_P, 0, NULL, 0);
    BIF_RET2(am_true, reds);
#else
    BIF_RET(am_false);
#endif
}

/**********************************************************************/
/* Return a list of active ports */

BIF_RETTYPE ports_0(BIF_ALIST_0)
{
    Eterm res = NIL;
    Eterm* port_buf = erts_alloc(ERTS_ALC_T_TMP,
				 sizeof(Eterm)*erts_max_ports);
    Eterm* pp = port_buf;
    Eterm* dead_ports;
    int alive, dead;
    Uint32 next_ss;

    /* To get a consistent snapshot... 
     * We add alive ports from start of the buffer
     * while dying ports are added from the other end by the killing threads.
     */

    erts_smp_mtx_lock(&ports_snapshot_mtx); /* One snapshot at a time */

    erts_smp_atomic_set(&erts_dead_ports_ptr,
			(erts_aint_t) (port_buf + erts_max_ports));

    next_ss = erts_smp_atomic_inctest(&erts_ports_snapshot);

    if (erts_smp_atomic_read(&erts_ports_alive) > 0) {
	erts_aint_t i;
	for (i = erts_max_ports-1; i >= 0; i--) {
	    Port* prt = &erts_port[i];
	    erts_smp_port_state_lock(prt);
	    if (!(prt->status & ERTS_PORT_SFLGS_DEAD)
		&& prt->snapshot != next_ss) {
		ASSERT(prt->snapshot == next_ss - 1);
		*pp++ = prt->id;		
		prt->snapshot = next_ss; /* Consumed by this snapshot */
	    }
	    erts_smp_port_state_unlock(prt);
	}
    }

    dead_ports = (Eterm*)erts_smp_atomic_xchg(&erts_dead_ports_ptr,
					      (erts_aint_t) NULL);
    erts_smp_mtx_unlock(&ports_snapshot_mtx);

    ASSERT(pp <= dead_ports);

    alive = pp - port_buf;
    dead = port_buf + erts_max_ports - dead_ports;

    ASSERT((alive+dead) <= erts_max_ports);

    if (alive+dead > 0) {
	erts_aint_t i;
	Eterm *hp = HAlloc(BIF_P, (alive+dead)*2);

	for (i = 0; i < alive; i++) {
	    res = CONS(hp, port_buf[i], res);	    
	    hp += 2;
	}
	for (i = 0; i < dead; i++) {
	    res = CONS(hp, dead_ports[i], res);
	    hp += 2;
	}
    }

    erts_free(ERTS_ALC_T_TMP, port_buf);

    BIF_RET(res);
}

/**********************************************************************/

BIF_RETTYPE throw_1(BIF_ALIST_1)
{
    BIF_P->fvalue = BIF_ARG_1;
    BIF_ERROR(BIF_P, EXC_THROWN);
}

/**********************************************************************/


/* 
 * Non-standard, undocumented, dirty BIF, meant for debugging.
 *
 */
BIF_RETTYPE display_1(BIF_ALIST_1)
{
    erts_printf("%.*T\n", INT_MAX, BIF_ARG_1);
    BIF_RET(am_true);
}

/*
 * erts_debug:display/1 is for debugging erlang:display/1
 */
BIF_RETTYPE erts_debug_display_1(BIF_ALIST_1)
{
    int pres;
    Eterm res;
    Eterm *hp;
    erts_dsprintf_buf_t *dsbufp = erts_create_tmp_dsbuf(64);       
    pres = erts_dsprintf(dsbufp, "%.*T\n", INT_MAX, BIF_ARG_1);
    if (pres < 0)
	erl_exit(1, "Failed to convert term to string: %d (%s)\n",
		 -pres, erl_errno_id(-pres));
    hp = HAlloc(BIF_P, 2*dsbufp->str_len); /* we need length * 2 heap words */
    res = buf_to_intlist(&hp, dsbufp->str, dsbufp->str_len, NIL);
    erts_printf("%s", dsbufp->str);
    erts_destroy_tmp_dsbuf(dsbufp);
    BIF_RET(res);
}


Eterm
display_string_1(Process* p, Eterm string)
{
    int len = is_string(string);
    char *str;

    if (len <= 0) {
	BIF_ERROR(p, BADARG);
    }
    str = (char *) erts_alloc(ERTS_ALC_T_TMP, sizeof(char)*(len + 1));
    if (intlist_to_buf(string, str, len) != len)
	erl_exit(1, "%s:%d: Internal error\n", __FILE__, __LINE__);
    str[len] = '\0';
    erts_fprintf(stderr, "%s", str);
    erts_free(ERTS_ALC_T_TMP, (void *) str);
    BIF_RET(am_true);
}

Eterm
display_nl_0(Process* p)
{
    erts_fprintf(stderr, "\n");
    BIF_RET(am_true);
}

/**********************************************************************/

/* stop the system */
/* ARGSUSED */
BIF_RETTYPE halt_0(BIF_ALIST_0)
{
    VERBOSE(DEBUG_SYSTEM,("System halted by BIF halt/0\n"));
    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
    erl_exit(0, "");
    return NIL;  /* Pedantic (lint does not know about erl_exit) */
}

/**********************************************************************/

#define MSG_SIZE	200

/* stop the system with exit code */
/* ARGSUSED */
BIF_RETTYPE halt_1(BIF_ALIST_1)
{
    Sint code;
    static char msg[MSG_SIZE];
    int i;
    
    if (is_small(BIF_ARG_1) && (code = signed_val(BIF_ARG_1)) >= 0) {
	VERBOSE(DEBUG_SYSTEM,("System halted by BIF halt(%d)\n", code));
	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erl_exit(-code, "");
    } else if (is_string(BIF_ARG_1) || BIF_ARG_1 == NIL) {
	if ((i = intlist_to_buf(BIF_ARG_1, msg, MSG_SIZE-1)) < 0) {
	    goto error;
	}
	msg[i] = '\0';
	VERBOSE(DEBUG_SYSTEM,("System halted by BIF halt(%s)\n", msg));
	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erl_exit(ERTS_DUMP_EXIT, "%s\n", msg);
    } else {
    error:
	BIF_ERROR(BIF_P, BADARG);
    }
    return NIL;  /* Pedantic (lint does not know about erl_exit) */
}

BIF_RETTYPE function_exported_3(BIF_ALIST_3)
{
    if (is_not_atom(BIF_ARG_1) ||
	is_not_atom(BIF_ARG_2) || 
	is_not_small(BIF_ARG_3)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    if (erts_find_function(BIF_ARG_1, BIF_ARG_2, signed_val(BIF_ARG_3)) == NULL) {
	BIF_RET(am_false);
    }
    BIF_RET(am_true);
}

/**********************************************************************/    

BIF_RETTYPE is_builtin_3(Process* p, Eterm Mod, Eterm Name, Eterm Arity)
{
    if (is_not_atom(Mod) || is_not_atom(Name) || is_not_small(Arity)) {
	BIF_ERROR(p, BADARG);
    }
    BIF_RET(erts_is_builtin(Mod, Name, signed_val(Arity)) ?
	    am_true : am_false);
}

/**********************************************************************/    

/* NOTE: Cannot be used in all *_to_list() bifs. erts_dsprintf() prints
 *       some terms on other formats than what is desired as results
 *       from *_to_list() bifs.
 */

static Eterm
term2list_dsprintf(Process *p, Eterm term)
{
    int pres;
    Eterm res;
    Eterm *hp;
    erts_dsprintf_buf_t *dsbufp = erts_create_tmp_dsbuf(64);       
    pres = erts_dsprintf(dsbufp, "%T", term);
    if (pres < 0)
	erl_exit(1, "Failed to convert term to list: %d (%s)\n",
		 -pres, erl_errno_id(-pres));
    hp = HAlloc(p, 2*dsbufp->str_len); /* we need length * 2 heap words */
    res = buf_to_intlist(&hp, dsbufp->str, dsbufp->str_len, NIL);
    erts_destroy_tmp_dsbuf(dsbufp);
    return res;
}

BIF_RETTYPE ref_to_list_1(BIF_ALIST_1)
{
    if (is_not_ref(BIF_ARG_1))
	BIF_ERROR(BIF_P, BADARG);
    BIF_RET(term2list_dsprintf(BIF_P, BIF_ARG_1));
}

BIF_RETTYPE make_fun_3(BIF_ALIST_3)
{
    Eterm* hp;
    Sint arity;

    if (is_not_atom(BIF_ARG_1) || is_not_atom(BIF_ARG_2) || is_not_small(BIF_ARG_3)) {
    error:
	BIF_ERROR(BIF_P, BADARG);
    }
    arity = signed_val(BIF_ARG_3);
    if (arity < 0) {
	goto error;
    }
#if HALFWORD_HEAP
    hp = HAlloc(BIF_P, 3);
    hp[0] = HEADER_EXPORT;
    /* Yes, May be misaligned, but X86_64 will fix it... */
    *((Export **) (hp+1)) = erts_export_get_or_make_stub(BIF_ARG_1, BIF_ARG_2, (Uint) arity);
#else
    hp = HAlloc(BIF_P, 2);
    hp[0] = HEADER_EXPORT;
    hp[1] = (Eterm) erts_export_get_or_make_stub(BIF_ARG_1, BIF_ARG_2, (Uint) arity);
#endif
    BIF_RET(make_export(hp));
}

Eterm
fun_to_list_1(Process* p, Eterm fun)
{
    if (is_not_any_fun(fun))
	BIF_ERROR(p, BADARG);
    BIF_RET(term2list_dsprintf(p, fun));
}

/**********************************************************************/    

/* convert a pid to an erlang list (for the linked cons cells) of the form
   <node.number.serial> to a PID
 */

BIF_RETTYPE pid_to_list_1(BIF_ALIST_1)
{
    if (is_not_pid(BIF_ARG_1))
	BIF_ERROR(BIF_P, BADARG);
    BIF_RET(term2list_dsprintf(BIF_P, BIF_ARG_1));
}

BIF_RETTYPE port_to_list_1(BIF_ALIST_1)
{
    if (is_not_port(BIF_ARG_1))
	BIF_ERROR(BIF_P, BADARG);
    BIF_RET(term2list_dsprintf(BIF_P, BIF_ARG_1));
}

/**********************************************************************/

/* convert a list of ascii characeters of the form
   <node.number.serial> to a PID
*/

BIF_RETTYPE list_to_pid_1(BIF_ALIST_1)
{
    Uint a = 0, b = 0, c = 0;
    char* cp;
    int i;
    DistEntry *dep = NULL;
    char *buf = (char *) erts_alloc(ERTS_ALC_T_TMP, 65);
    /*
     * Max 'Uint64' has 20 decimal digits. If X, Y, Z in <X.Y.Z>
     * are 'Uint64's. Max chars are 1 + 20 + 1 + 20 + 1 + 20 + 1 = 64,
     * i.e, if the input list is longer than 64 it does not represent
     * a pid.
     */

    /* walk down the list and create a C string */
    if ((i = intlist_to_buf(BIF_ARG_1, buf, 64)) < 0)
	goto bad;

    buf[i] = '\0';		/* null terminal */

    cp = buf;
    if (*cp++ != '<') goto bad;
    
    if (*cp < '0' || *cp > '9') goto bad;
    while(*cp >= '0' && *cp <= '9') { a = 10*a + (*cp - '0'); cp++; }

    if (*cp++ != '.') goto bad;

    if (*cp < '0' || *cp > '9') goto bad;
    while(*cp >= '0' && *cp <= '9') { b = 10*b + (*cp - '0'); cp++; }

    if (*cp++ != '.') goto bad;

    if (*cp < '0' || *cp > '9') goto bad;
    while(*cp >= '0' && *cp <= '9') { c = 10*c + (*cp - '0'); cp++; }

    if (*cp++ != '>') goto bad;
    if (*cp != '\0') goto bad;

    erts_free(ERTS_ALC_T_TMP, (void *) buf);
    buf = NULL;

    /* <a.b.c> a = node, b = process number, c = serial */

    dep = erts_channel_no_to_dist_entry(a);

    if (!dep)
	goto bad;


    if (c > ERTS_MAX_PID_SERIAL || b > ERTS_MAX_PID_NUMBER)
	goto bad;

    if(dep == erts_this_dist_entry) {
	erts_deref_dist_entry(dep);
	BIF_RET(make_internal_pid(make_pid_data(c, b)));
    }
    else {
      ExternalThing *etp;
      ErlNode *enp;

      if (is_nil(dep->cid))
	  goto bad;
      
      enp = erts_find_or_insert_node(dep->sysname, dep->creation);

      etp = (ExternalThing *) HAlloc(BIF_P, EXTERNAL_THING_HEAD_SIZE + 1);
      etp->header = make_external_pid_header(1);
      etp->next = MSO(BIF_P).first;
      etp->node = enp;
      etp->data.ui[0] = make_pid_data(c, b);

      MSO(BIF_P).first = (struct erl_off_heap_header*) etp;
      erts_deref_dist_entry(dep);
      BIF_RET(make_external_pid(etp));
    }

 bad:
    if (dep)
	erts_deref_dist_entry(dep);
    if (buf)
	erts_free(ERTS_ALC_T_TMP, (void *) buf);
    BIF_ERROR(BIF_P, BADARG);
}

/**********************************************************************/

BIF_RETTYPE group_leader_0(BIF_ALIST_0)
{
    BIF_RET(BIF_P->group_leader);
}

/**********************************************************************/
/* arg1 == leader, arg2 == new member */

BIF_RETTYPE group_leader_2(BIF_ALIST_2)
{
    Process* new_member;

    if (is_not_pid(BIF_ARG_1)) {
	BIF_ERROR(BIF_P, BADARG);
    }

    if (is_external_pid(BIF_ARG_2)) {
	DistEntry *dep;
	int code;
	ErtsDSigData dsd;
	dep = external_pid_dist_entry(BIF_ARG_2);
	if(dep == erts_this_dist_entry)
	    BIF_ERROR(BIF_P, BADARG);

	code = erts_dsig_prepare(&dsd, dep, BIF_P, ERTS_DSP_NO_LOCK, 0);
	switch (code) {
	case ERTS_DSIG_PREP_NOT_ALIVE:
	    BIF_RET(am_true);
	case ERTS_DSIG_PREP_NOT_CONNECTED:
	    BIF_TRAP2(dgroup_leader_trap, BIF_P, BIF_ARG_1, BIF_ARG_2);
	case ERTS_DSIG_PREP_CONNECTED:
	    code = erts_dsig_send_group_leader(&dsd, BIF_ARG_1, BIF_ARG_2);
	    if (code == ERTS_DSIG_SEND_YIELD)
		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
	    BIF_RET(am_true);
	default:
	    ASSERT(! "Invalid dsig prepare result");
	    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
	}
    }
    else if (is_internal_pid(BIF_ARG_2)) {
	int await_x;
	ErtsProcLocks locks = ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS;
	new_member = erts_pid2proc_nropt(BIF_P, ERTS_PROC_LOCK_MAIN,
					 BIF_ARG_2, locks);
	if (!new_member)
	    BIF_ERROR(BIF_P, BADARG);

	if (new_member == ERTS_PROC_LOCK_BUSY)
	    ERTS_BIF_YIELD2(bif_export[BIF_group_leader_2], BIF_P,
			    BIF_ARG_1, BIF_ARG_2);

	await_x = (new_member != BIF_P
		   && ERTS_PROC_PENDING_EXIT(new_member));
	if (!await_x) {
	    if (is_immed(BIF_ARG_1))
		new_member->group_leader = BIF_ARG_1;
	    else {
		locks &= ~ERTS_PROC_LOCK_STATUS;
		erts_smp_proc_unlock(new_member, ERTS_PROC_LOCK_STATUS);
		new_member->group_leader = STORE_NC_IN_PROC(new_member,
							    BIF_ARG_1);
	    }
	}

	if (new_member == BIF_P)
	    locks &= ~ERTS_PROC_LOCK_MAIN;
	if (locks)
	    erts_smp_proc_unlock(new_member, locks);

	if (await_x) {
	    /* Wait for new_member to terminate; then badarg */
	    Eterm args[2] = {BIF_ARG_1, BIF_ARG_2};
	    ERTS_BIF_AWAIT_X_APPLY_TRAP(BIF_P,
					BIF_ARG_2,
					am_erlang,
					am_group_leader,
					args,
					2);
	}

	BIF_RET(am_true);
    }
    else {
	BIF_ERROR(BIF_P, BADARG);
    }
}
    
BIF_RETTYPE system_flag_2(BIF_ALIST_2)    
{
    Sint n;

    if (BIF_ARG_1 == am_multi_scheduling) {
	if (BIF_ARG_2 == am_block || BIF_ARG_2 == am_unblock) {
#ifndef ERTS_SMP
	    BIF_RET(am_disabled);
#else
	    if (erts_no_schedulers == 1)
		BIF_RET(am_disabled);
	    else {
		switch (erts_block_multi_scheduling(BIF_P,
						    ERTS_PROC_LOCK_MAIN,
						    BIF_ARG_2 == am_block,
						    0)) {
		case ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED:
		    BIF_RET(am_blocked);
		case ERTS_SCHDLR_SSPND_YIELD_DONE_MSCHED_BLOCKED:
		    ERTS_BIF_YIELD_RETURN_X(BIF_P, am_blocked,
					    am_multi_scheduling);
		case ERTS_SCHDLR_SSPND_DONE:
		    BIF_RET(am_enabled);
		case ERTS_SCHDLR_SSPND_YIELD_RESTART:
		    ERTS_VBUMP_ALL_REDS(BIF_P);
		    BIF_TRAP2(bif_export[BIF_system_flag_2],
			      BIF_P, BIF_ARG_1, BIF_ARG_2);
		case ERTS_SCHDLR_SSPND_YIELD_DONE:
		    ERTS_BIF_YIELD_RETURN_X(BIF_P, am_enabled,
					    am_multi_scheduling);
		case ERTS_SCHDLR_SSPND_EINVAL:
		    goto error;
		default:
		    ASSERT(0);
		    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
		    break;
		}
	    }
#endif
	}
    } else if (BIF_ARG_1 == am_schedulers_online) {
#ifndef ERTS_SMP
	if (BIF_ARG_2 != make_small(1))
	    goto error;
	else
	    BIF_RET(make_small(1));
#else
	Sint old_no;
	if (!is_small(BIF_ARG_2))
	    goto error;
	switch (erts_set_schedulers_online(BIF_P,
					   ERTS_PROC_LOCK_MAIN,
					   signed_val(BIF_ARG_2),
					   &old_no)) {
	case ERTS_SCHDLR_SSPND_DONE:
	    BIF_RET(make_small(old_no));
	case ERTS_SCHDLR_SSPND_YIELD_RESTART:
	    ERTS_VBUMP_ALL_REDS(BIF_P);
	    BIF_TRAP2(bif_export[BIF_system_flag_2],
		      BIF_P, BIF_ARG_1, BIF_ARG_2);
	case ERTS_SCHDLR_SSPND_YIELD_DONE:
	    ERTS_BIF_YIELD_RETURN_X(BIF_P, make_small(old_no),
				    am_schedulers_online);
	case ERTS_SCHDLR_SSPND_EINVAL:
	    goto error;
	default:
	    ASSERT(0);
	    BIF_ERROR(BIF_P, EXC_INTERNAL_ERROR);
	    break;
	}
#endif
    } else if (BIF_ARG_1 == am_fullsweep_after) {
	Uint16 nval;
	Uint oval;
	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
	    goto error;
	}
	nval = (n > (Sint) ((Uint16) -1)) ? ((Uint16) -1) : ((Uint16) n);
	oval = (Uint) erts_smp_atomic32_xchg(&erts_max_gen_gcs,
					     (erts_aint32_t) nval);
	BIF_RET(make_small(oval));
    } else if (BIF_ARG_1 == am_min_heap_size) {
	int oval = H_MIN_SIZE;

	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
	    goto error;
	}

	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erts_smp_block_system(0);

	H_MIN_SIZE = erts_next_heap_size(n, 0);

	erts_smp_release_system();
	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);

	BIF_RET(make_small(oval));
    } else if (BIF_ARG_1 == am_min_bin_vheap_size) {
	int oval = BIN_VH_MIN_SIZE;

	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
	    goto error;
	}

	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erts_smp_block_system(0);

	BIN_VH_MIN_SIZE = erts_next_heap_size(n, 0);

	erts_smp_release_system();
	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);

	BIF_RET(make_small(oval));
    } else if (BIF_ARG_1 == am_display_items) {
	int oval = display_items;
	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
	    goto error;
	}
	display_items = n < 32 ? 32 : n;
	BIF_RET(make_small(oval));
    } else if (BIF_ARG_1 == am_debug_flags) {
	BIF_RET(am_true);
    } else if (BIF_ARG_1 == am_backtrace_depth) {
	int oval = erts_backtrace_depth;
	if (!is_small(BIF_ARG_2) || (n = signed_val(BIF_ARG_2)) < 0) {
	    goto error;
	}
	if (n > MAX_BACKTRACE_SIZE) n = MAX_BACKTRACE_SIZE;
	erts_backtrace_depth = n;
	BIF_RET(make_small(oval));
    } else if (BIF_ARG_1 == am_trace_control_word) {
	BIF_RET(db_set_trace_control_word_1(BIF_P, BIF_ARG_2));
    } else if (BIF_ARG_1 == am_sequential_tracer) {
        Eterm old_value = erts_set_system_seq_tracer(BIF_P,
						     ERTS_PROC_LOCK_MAIN,
						     BIF_ARG_2);
	if (old_value != THE_NON_VALUE) {
	    BIF_RET(old_value);
	}
    } else if (BIF_ARG_1 == make_small(1)) {
	Uint i;
	ErlMessage* mp;
	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erts_smp_block_system(0);

	for (i = 0; i < erts_max_processes; i++) {
	    if (process_tab[i] != (Process*) 0) {
		Process* p = process_tab[i];
		p->seq_trace_token = NIL;
		p->seq_trace_clock = 0;
		p->seq_trace_lastcnt = 0;
		ERTS_SMP_MSGQ_MV_INQ2PRIVQ(p);
		mp = p->msg.first;
		while(mp != NULL) {
		    ERL_MESSAGE_TOKEN(mp) = NIL;
		    mp = mp->next;
		}
	    }
	}

	erts_smp_release_system();
	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);

	BIF_RET(am_true);
    } else if (ERTS_IS_ATOM_STR("scheduling_statistics", BIF_ARG_1)) {
	int what;
	if (ERTS_IS_ATOM_STR("disable", BIF_ARG_2))
	    what = ERTS_SCHED_STAT_MODIFY_DISABLE;
	else if (ERTS_IS_ATOM_STR("enable", BIF_ARG_2))
	    what = ERTS_SCHED_STAT_MODIFY_ENABLE;
	else if (ERTS_IS_ATOM_STR("clear", BIF_ARG_2))
	    what = ERTS_SCHED_STAT_MODIFY_CLEAR;
	else
	    goto error;
	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
	erts_sched_stat_modify(what);
	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
	BIF_RET(am_true);
    } else if (ERTS_IS_ATOM_STR("internal_cpu_topology", BIF_ARG_1)) {
	Eterm res = erts_set_cpu_topology(BIF_P, BIF_ARG_2);
	if (is_value(res))
	    BIF_RET(res);
    } else if (ERTS_IS_ATOM_STR("cpu_topology", BIF_ARG_1)) {
	BIF_TRAP1(set_cpu_topology_trap, BIF_P, BIF_ARG_2);
    } else if (ERTS_IS_ATOM_STR("scheduler_bind_type", BIF_ARG_1)) {
	return erts_bind_schedulers(BIF_P, BIF_ARG_2);
    }
    error:
    BIF_ERROR(BIF_P, BADARG);
}

/**********************************************************************/

BIF_RETTYPE hash_2(BIF_ALIST_2)
{
    Uint32 hash;
    Sint range;

    if (is_not_small(BIF_ARG_2)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    if ((range = signed_val(BIF_ARG_2)) <= 0) {  /* [1..MAX_SMALL] */
	BIF_ERROR(BIF_P, BADARG);
    }
#if defined(ARCH_64) && !HALFWORD_HEAP
    if (range > ((1L << 27) - 1))
	BIF_ERROR(BIF_P, BADARG);
#endif
    hash = make_broken_hash(BIF_ARG_1);
    BIF_RET(make_small(1 + (hash % range)));   /* [1..range] */
}

BIF_RETTYPE phash_2(BIF_ALIST_2)
{
    Uint32 hash;
    Uint32 final_hash;
    Uint32 range;

    /* Check for special case 2^32 */
    if (term_equals_2pow32(BIF_ARG_2)) {
	range = 0;
    } else {
	Uint u;
	if (!term_to_Uint(BIF_ARG_2, &u) || ((u >> 16) >> 16) != 0 || !u) {
	    BIF_ERROR(BIF_P, BADARG);
	}
	range = (Uint32) u;
    }
    hash = make_hash(BIF_ARG_1);
    if (range) {
	final_hash = 1 + (hash % range); /* [1..range] */
    } else if ((final_hash = hash + 1) == 0) {
	/*
	 * XXX In this case, there will still be a ArithAlloc() in erts_mixed_plus().
	 */
	BIF_RET(erts_mixed_plus(BIF_P,
				erts_make_integer(hash, BIF_P),
				make_small(1)));
    }

    BIF_RET(erts_make_integer(final_hash, BIF_P));
}

BIF_RETTYPE phash2_1(BIF_ALIST_1)
{
    Uint32 hash;

    hash = make_hash2(BIF_ARG_1);
    BIF_RET(make_small(hash & ((1L << 27) - 1)));
}

BIF_RETTYPE phash2_2(BIF_ALIST_2)
{
    Uint32 hash;
    Uint32 final_hash;
    Uint32 range;

    /* Check for special case 2^32 */
    if (term_equals_2pow32(BIF_ARG_2)) {
	range = 0;
    } else {
	Uint u;
	if (!term_to_Uint(BIF_ARG_2, &u) || ((u >> 16) >> 16) != 0 || !u) {
	    BIF_ERROR(BIF_P, BADARG);
	}
	range = (Uint32) u;
    }
    hash = make_hash2(BIF_ARG_1);
    if (range) {
	final_hash = hash % range; /* [0..range-1] */
    } else {
	final_hash = hash;
    }
    /*
     * Return either a small or a big. Use the heap for bigs if there is room.
     */
#if defined(ARCH_64) && !HALFWORD_HEAP
    BIF_RET(make_small(final_hash));
#else
    if (IS_USMALL(0, final_hash)) {
	BIF_RET(make_small(final_hash));
    } else {
	Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
	BIF_RET(uint_to_big(final_hash, hp));
    }
#endif
}

BIF_RETTYPE bump_reductions_1(BIF_ALIST_1)
{
    Sint reds;
	
    if (is_not_small(BIF_ARG_1) || ((reds = signed_val(BIF_ARG_1)) < 0)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    
    if (reds > CONTEXT_REDS) {
        reds = CONTEXT_REDS;
    }
    BIF_RET2(am_true, reds);
}

/*
 * Processes doing yield on return in a bif ends up in bif_return_trap().
 */
static BIF_RETTYPE bif_return_trap(
#ifdef DEBUG
    BIF_ALIST_2
#else
    BIF_ALIST_1
#endif
    )
{
#ifdef DEBUG
    switch (BIF_ARG_2) {
    case am_multi_scheduling:
#ifdef ERTS_SMP
	erts_dbg_multi_scheduling_return_trap(BIF_P, BIF_ARG_1);
#endif
	break;
    case am_schedulers_online:
	break;
    default:
	break;
    }
#endif

    BIF_RET(BIF_ARG_1);
}

/*
 * NOTE: The erts_bif_prep_await_proc_exit_*() functions are
 * tightly coupled with the implementation of erlang:await_proc_exit/3.
 * The erts_bif_prep_await_proc_exit_*() functions can safely call
 * skip_current_msgq() since they know that erlang:await_proc_exit/3
 * unconditionally will do a monitor and then unconditionally will
 * wait for the corresponding 'DOWN' message in a receive, and no other
 * receive is done before this receive. This optimization removes an
 * unnecessary scan of the currently existing message queue (which
 * can be large). If the erlang:await_proc_exit/3 implementation
 * is changed so that the above isn't true, nasty bugs in later
 * receives, etc, may appear.
 */

static ERTS_INLINE int
skip_current_msgq(Process *c_p)
{
    int res;
#if defined(ERTS_ENABLE_LOCK_CHECK) && defined(ERTS_SMP)
    erts_proc_lc_chk_only_proc_main(c_p);
#endif

    erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE);
    if (ERTS_PROC_PENDING_EXIT(c_p)) {
	KILL_CATCHES(c_p);
	c_p->freason = EXC_EXIT;
	res = 0;
    }
    else {
	ERTS_SMP_MSGQ_MV_INQ2PRIVQ(c_p);
	c_p->msg.save = c_p->msg.last;
	res = 1;
    }
    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE);
    return res;
}

void
erts_bif_prep_await_proc_exit_data_trap(Process *c_p, Eterm pid, Eterm ret)
{
    if (skip_current_msgq(c_p)) {
	Eterm unused;
	ERTS_BIF_PREP_TRAP3(unused, await_proc_exit_trap, c_p, pid, am_data, ret);
    }
}

void
erts_bif_prep_await_proc_exit_reason_trap(Process *c_p, Eterm pid)
{
    if (skip_current_msgq(c_p)) {
	Eterm unused;
	ERTS_BIF_PREP_TRAP3(unused, await_proc_exit_trap, c_p,
			    pid, am_reason, am_undefined);
    }
}

void
erts_bif_prep_await_proc_exit_apply_trap(Process *c_p,
					 Eterm pid,
					 Eterm module,
					 Eterm function,
					 Eterm args[],
					 int nargs)
{
    ASSERT(is_atom(module) && is_atom(function));
    if (skip_current_msgq(c_p)) {
	Eterm unused;
	Eterm term;
	Eterm *hp;
	int i;

	hp = HAlloc(c_p, 4+2*nargs);
	term = NIL;
	for (i = nargs-1; i >= 0; i--) {
	    term = CONS(hp, args[i], term);
	    hp += 2;
	}
	term = TUPLE3(hp, module, function, term);
	ERTS_BIF_PREP_TRAP3(unused, await_proc_exit_trap, c_p, pid, am_apply, term);
    }
}

Export bif_return_trap_export;

void erts_init_bif(void)
{
    reference0 = 0;
    reference1 = 0;
    reference2 = 0;

    erts_smp_spinlock_init(&make_ref_lock, "make_ref");
    erts_smp_mtx_init(&ports_snapshot_mtx, "ports_snapshot");
    erts_smp_atomic_init(&erts_dead_ports_ptr, (erts_aint_t) NULL);

    /*
     * bif_return_trap/1 is a hidden BIF that bifs that need to
     * yield the calling process traps to. The only thing it does:
     * return the value passed as argument.
     */
    sys_memset((void *) &bif_return_trap_export, 0, sizeof(Export));
    bif_return_trap_export.address = &bif_return_trap_export.code[3];
    bif_return_trap_export.code[0] = am_erlang;
    bif_return_trap_export.code[1] = am_bif_return_trap;
#ifdef DEBUG
    bif_return_trap_export.code[2] = 2;
#else
    bif_return_trap_export.code[2] = 1;
#endif
    bif_return_trap_export.code[3] = (BeamInstr) em_apply_bif;
    bif_return_trap_export.code[4] = (BeamInstr) &bif_return_trap;

    flush_monitor_message_trap = erts_export_put(am_erlang,
						 am_flush_monitor_message,
						 2);

    set_cpu_topology_trap = erts_export_put(am_erlang,
					    am_set_cpu_topology,
					    1);
    erts_format_cpu_topology_trap = erts_export_put(am_erlang,
						    am_format_cpu_topology,
						    1);
    await_proc_exit_trap = erts_export_put(am_erlang,am_await_proc_exit,3);
}

#ifdef HARDDEBUG
/*
You'll need this line in bif.tab to be able to use this debug bif

bif erlang:send_to_logger/2

*/
BIF_RETTYPE send_to_logger_2(BIF_ALIST_2)
{
    byte *buf;
    int len;
    if (!is_atom(BIF_ARG_1) || !(is_list(BIF_ARG_2) ||
				 is_nil(BIF_ARG_1))) {
	BIF_ERROR(BIF_P,BADARG);
    }
    len = io_list_len(BIF_ARG_2);
    if (len < 0)
	BIF_ERROR(BIF_P,BADARG);
    else if (len == 0)
	buf = "";
    else {
#ifdef DEBUG
	int len2;
#endif
	buf = (byte *) erts_alloc(ERTS_ALC_T_TMP, len+1);
#ifdef DEBUG
	len2 =
#else
	(void)
#endif
	    io_list_to_buf(BIF_ARG_2, buf, len);
	ASSERT(len2 == len);
	buf[len] = '\0';
	switch (BIF_ARG_1) {
	case am_info:
	    erts_send_info_to_logger(BIF_P->group_leader, buf, len);
	    break;
	case am_warning:
	    erts_send_warning_to_logger(BIF_P->group_leader, buf, len);
	    break;
	case am_error:
	    erts_send_error_to_logger(BIF_P->group_leader, buf, len);
	    break;
	default:
	{
	    BIF_ERROR(BIF_P,BADARG);
	}
	}
	erts_free(ERTS_ALC_T_TMP, (void *) buf);
    }
    BIF_RET(am_true);
}
#endif /* HARDDEBUG */

BIF_RETTYPE get_module_info_1(BIF_ALIST_1)
{
    Eterm ret = erts_module_info_0(BIF_P, BIF_ARG_1);

    if (is_non_value(ret)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    BIF_RET(ret);
}


BIF_RETTYPE get_module_info_2(BIF_ALIST_2)
{
    Eterm ret = erts_module_info_1(BIF_P, BIF_ARG_1, BIF_ARG_2);

    if (is_non_value(ret)) {
	BIF_ERROR(BIF_P, BADARG);
    }
    BIF_RET(ret);
}