Rewrite ethread library

Large parts of the ethread library have been rewritten. The
ethread library is an Erlang runtime system internal, portable
thread library used by the runtime system itself.

Most notable improvement is a reader optimized rwlock
implementation which dramatically improve the performance of
read-lock/read-unlock operations on multi processor systems by
avoiding ping-ponging of the rwlock cache lines. The reader
optimized rwlock implementation is used by miscellaneous
rwlocks in the runtime system that are known to be read-locked
frequently, and can be enabled on ETS tables by passing the
`{read_concurrency, true}' option upon table creation. See the
documentation of `ets:new/2' for more information.

The ethread library can now also use the libatomic_ops library
for atomic memory accesses. This makes it possible for the
Erlang runtime system to utilize optimized atomic operations
on more platforms than before. Use the
`--with-libatomic_ops=PATH' configure command line argument
when specifying where the libatomic_ops installation is
located. The libatomic_ops library can be downloaded from:
http://www.hpl.hp.com/research/linux/atomic_ops/

The changed API of the ethread library has also caused
modifications in the Erlang runtime system. Preparations for
the to come "delayed deallocation" feature has also been done
since it depends on the ethread library.

Note: When building for x86, the ethread library will now use
instructions that first appeared on the pentium 4 processor. If
you want the runtime system to be compatible with older
processors (back to 486) you need to pass the
`--enable-ethread-pre-pentium4-compatibility' configure command
line argument when configuring the system.

1 files changed, 163 insertions, 11 deletions

diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 16ae643ed9..87503af7d5 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -64,6 +64,14 @@
 
 #ifdef DEBUG
 static Uint install_debug_functions(void);
+#if 0
+#define HARD_DEBUG
+#ifdef __GNUC__
+#warning "* * * * * * * * * * * * * *"
+#warning "* HARD DEBUG IS ENABLED!  *"
+#warning "* * * * * * * * * * * * * *"
+#endif
+#endif
 #endif
 extern void elib_ensure_initialized(void);
 
@@ -391,6 +399,10 @@ refuse_af_strategy(struct au_init *init)
 
 static void init_thr_ix(int static_ixs);
 
+#ifdef HARD_DEBUG
+static void hdbg_init(void);
+#endif
+
 void
 erts_alloc_init(int *argc, char **argv, ErtsAllocInitOpts *eaiop)
 {
@@ -406,6 +418,10 @@ erts_alloc_init(int *argc, char **argv, ErtsAllocInitOpts *eaiop)
 	ERTS_DEFAULT_ALCU_INIT
     };
 
+#ifdef HARD_DEBUG
+    hdbg_init();
+#endif
+
     erts_sys_alloc_init();
     init_thr_ix(erts_no_schedulers);
     erts_init_utils_mem();
@@ -2862,12 +2878,10 @@ unsigned long erts_alc_test(unsigned long op,
 	    break;
 	}
 	case 0xf0a:
-	    if (ethr_mutex_lock((ethr_mutex *) a1) != 0)
-		ERTS_ALC_TEST_ABORT;
+	    ethr_mutex_lock((ethr_mutex *) a1);
 	    break;
 	case 0xf0b:
-	    if (ethr_mutex_unlock((ethr_mutex *) a1) != 0)
-		ERTS_ALC_TEST_ABORT;
+	    ethr_mutex_unlock((ethr_mutex *) a1);
 	    break;
 	case 0xf0c: {
 	    ethr_cond *cnd = erts_alloc(ERTS_ALC_T_UNDEF, sizeof(ethr_cond));
@@ -2883,16 +2897,13 @@ unsigned long erts_alc_test(unsigned long op,
 	    break;
 	}
 	case 0xf0e:
-	    if (ethr_cond_broadcast((ethr_cond *) a1) != 0)
-		ERTS_ALC_TEST_ABORT;
+	    ethr_cond_broadcast((ethr_cond *) a1);
 	    break;
 	case 0xf0f: {
 	    int res;
 	    do {
 		res = ethr_cond_wait((ethr_cond *) a1, (ethr_mutex *) a2);
 	    } while (res == EINTR);
-	    if (res != 0)
-		ERTS_ALC_TEST_ABORT;
 	    break;
 	}
 	case 0xf10: {
@@ -2939,8 +2950,11 @@ unsigned long erts_alc_test(unsigned long op,
 #undef PRINT_OPS
 #endif
 
-
+#ifdef HARD_DEBUG
+#define FENCE_SZ		(4*sizeof(UWord))
+#else
 #define FENCE_SZ		(3*sizeof(UWord))
+#endif
 
 #if defined(ARCH_64)
 #define FENCE_PATTERN 0xABCDEF97ABCDEF97
@@ -2962,6 +2976,104 @@ unsigned long erts_alc_test(unsigned long op,
 #define GET_TYPE_OF_PATTERN(P) \
   (((P) >> TYPE_PATTERN_SHIFT) & TYPE_PATTERN_MASK)
 
+#ifdef HARD_DEBUG
+
+#define ERL_ALC_HDBG_MAX_MBLK 100000
+#define ERTS_ALC_O_CHECK -1
+
+typedef struct hdbg_mblk_ hdbg_mblk;
+struct hdbg_mblk_ {
+    hdbg_mblk *next;
+    hdbg_mblk *prev;
+    void *p;
+    Uint s;
+    ErtsAlcType_t n;
+};
+
+static hdbg_mblk hdbg_mblks[ERL_ALC_HDBG_MAX_MBLK];
+
+static hdbg_mblk *free_hdbg_mblks;
+static hdbg_mblk *used_hdbg_mblks;
+static erts_mtx_t hdbg_mblk_mtx;
+
+static void
+hdbg_init(void)
+{
+    int i;
+    for (i = 0; i < ERL_ALC_HDBG_MAX_MBLK-1; i++)
+	hdbg_mblks[i].next = &hdbg_mblks[i+1];
+    hdbg_mblks[ERL_ALC_HDBG_MAX_MBLK-1].next = NULL;
+    free_hdbg_mblks = &hdbg_mblks[0];
+    used_hdbg_mblks = NULL;
+    erts_mtx_init(&hdbg_mblk_mtx, "erts_alloc_hard_debug");
+}
+
+static void *check_memory_fence(void *ptr,
+				Uint *size,
+				ErtsAlcType_t n,
+				int func);
+void erts_hdbg_chk_blks(void);
+
+void
+erts_hdbg_chk_blks(void)
+{
+    hdbg_mblk *mblk;
+
+    erts_mtx_lock(&hdbg_mblk_mtx);
+    for (mblk = used_hdbg_mblks; mblk; mblk = mblk->next) {
+	Uint sz;
+	check_memory_fence(mblk->p, &sz, mblk->n, ERTS_ALC_O_CHECK);
+	ASSERT(sz == mblk->s);
+    }
+    erts_mtx_unlock(&hdbg_mblk_mtx);
+}
+
+static hdbg_mblk *
+hdbg_alloc(void *p, Uint s, ErtsAlcType_t n)
+{
+    hdbg_mblk *mblk;
+
+    erts_mtx_lock(&hdbg_mblk_mtx);
+    mblk = free_hdbg_mblks;
+    if (!mblk) {
+	erts_fprintf(stderr,
+		     "Ran out of debug blocks; please increase "
+		     "ERL_ALC_HDBG_MAX_MBLK=%d and recompile!\n",
+		     ERL_ALC_HDBG_MAX_MBLK);
+	abort();
+    }
+    free_hdbg_mblks = mblk->next;
+
+    mblk->p = p;
+    mblk->s = s;
+    mblk->n = n;
+
+    mblk->next = used_hdbg_mblks;
+    mblk->prev = NULL;
+    if (used_hdbg_mblks)
+	used_hdbg_mblks->prev = mblk;
+    used_hdbg_mblks = mblk;
+    erts_mtx_unlock(&hdbg_mblk_mtx);
+    return (void *) mblk;
+}
+
+static void
+hdbg_free(hdbg_mblk *mblk)
+{
+    erts_mtx_lock(&hdbg_mblk_mtx);
+    if (mblk->next)
+	mblk->next->prev = mblk->prev;
+    if (mblk->prev)
+	mblk->prev->next = mblk->next;
+    else
+	used_hdbg_mblks = mblk->next;
+
+    mblk->next = free_hdbg_mblks;
+    free_hdbg_mblks = mblk;
+    erts_mtx_unlock(&hdbg_mblk_mtx);
+}
+
+#endif
 
 #ifdef  ERTS_ALLOC_UTIL_HARD_DEBUG
 static void *check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func);
@@ -3007,17 +3119,28 @@ set_memory_fence(void *ptr, Uint sz, ErtsAlcType_t n)
 {
     UWord *ui_ptr;
     UWord pattern;
+#ifdef HARD_DEBUG
+    hdbg_mblk **mblkpp;
+#endif
 
     if (!ptr)
 	return NULL;
 
     ui_ptr = (UWord *) ptr;
     pattern = MK_PATTERN(n);
-    
+
+#ifdef HARD_DEBUG
+    mblkpp = (hdbg_mblk **) ui_ptr++;
+#endif
+
     *(ui_ptr++) = sz;
     *(ui_ptr++) = pattern;
     memcpy((void *) (((char *) ui_ptr)+sz), (void *) &pattern, sizeof(UWord));
 
+#ifdef HARD_DEBUG
+    *mblkpp = hdbg_alloc((void *) ui_ptr, sz, n);
+#endif
+
     return (void *) ui_ptr;
 }
 
@@ -3029,6 +3152,9 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
     UWord pre_pattern;
     UWord post_pattern;
     UWord *ui_ptr;
+#ifdef HARD_DEBUG
+    hdbg_mblk *mblk;
+#endif
 
     if (!ptr)
 	return NULL;
@@ -3036,6 +3162,9 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
     ui_ptr = (UWord *) ptr;
     pre_pattern = *(--ui_ptr);
     *size = sz = *(--ui_ptr);
+#ifdef HARD_DEBUG
+    mblk = (hdbg_mblk *) *(--ui_ptr);
+#endif
 
     found_type = GET_TYPE_OF_PATTERN(pre_pattern);
     if (pre_pattern != MK_PATTERN(n)) {
@@ -3091,6 +3220,17 @@ check_memory_fence(void *ptr, Uint *size, ErtsAlcType_t n, int func)
 		 (unsigned long) ptr, (unsigned long) sz, ftype, op_str, otype);
     }
 
+#ifdef HARD_DEBUG
+    switch (func) {
+    case ERTS_ALC_O_REALLOC:
+    case ERTS_ALC_O_FREE:
+	hdbg_free(mblk);
+	break;
+    default:
+	break;
+    }
+#endif
+
     return (void *) ui_ptr;
 }
 
@@ -3103,6 +3243,10 @@ debug_alloc(ErtsAlcType_t n, void *extra, Uint size)
     Uint dsize;
     void *res;
 
+#ifdef HARD_DEBUG
+    erts_hdbg_chk_blks();
+#endif
+
     ASSERT(ERTS_ALC_N_MIN <= n && n <= ERTS_ALC_N_MAX);
     dsize = size + FENCE_SZ;
     res = (*real_af->alloc)(n, real_af->extra, dsize);
@@ -3132,13 +3276,17 @@ debug_realloc(ErtsAlcType_t n, void *extra, void *ptr, Uint size)
     dsize = size + FENCE_SZ;
     dptr = check_memory_fence(ptr, &old_size, n, ERTS_ALC_O_REALLOC);
 
+#ifdef HARD_DEBUG
+    erts_hdbg_chk_blks();
+#endif
+
     if (old_size > size)
 	sys_memset((void *) (((char *) ptr) + size),
 		   0xf,
 		   sizeof(Uint) + old_size - size);
 
     res = (*real_af->realloc)(n, real_af->extra, dptr, dsize);
-    
+
     res = set_memory_fence(res, size, n);
 
 #ifdef PRINT_OPS
@@ -3168,6 +3316,10 @@ debug_free(ErtsAlcType_t n, void *extra, void *ptr)
     fprintf(stderr, "free(%s, 0x%lx)\r\n", ERTS_ALC_N2TD(n), (Uint) ptr);
 #endif
 
+#ifdef HARD_DEBUG
+    erts_hdbg_chk_blks();
+#endif
+
 }
 
 static Uint