/* * %CopyrightBegin% * * Copyright Ericsson AB 2002-2014. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * %CopyrightEnd% */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #define ERL_WANT_GC_INTERNALS__ #include "sys.h" #include "erl_vm.h" #include "global.h" #include "erl_process.h" #include "erl_db.h" #include "beam_catches.h" #include "erl_binary.h" #include "erl_bits.h" #include "erl_map.h" #include "error.h" #include "big.h" #include "erl_gc.h" #if HIPE #include "hipe_stack.h" #include "hipe_mode_switch.h" #endif #include "dtrace-wrapper.h" #include "erl_bif_unique.h" #define ERTS_INACT_WR_PB_LEAVE_MUCH_LIMIT 1 #define ERTS_INACT_WR_PB_LEAVE_MUCH_PERCENTAGE 20 #define ERTS_INACT_WR_PB_LEAVE_LIMIT 10 #define ERTS_INACT_WR_PB_LEAVE_PERCENTAGE 10 #if defined(DEBUG) || 0 #define ERTS_GC_DEBUG #else #undef ERTS_GC_DEBUG #endif #ifdef ERTS_GC_DEBUG # define ERTS_GC_ASSERT ASSERT #else # define ERTS_GC_ASSERT(B) ((void) 1) #endif /* * Returns number of elements in an array. */ #define ALENGTH(a) (sizeof(a)/sizeof(a[0])) # define STACK_SZ_ON_HEAP(p) ((p)->hend - (p)->stop) # define OverRunCheck(P) \ if ((P)->stop < (P)->htop) { \ erts_fprintf(stderr, "hend=%p\n", (p)->hend); \ erts_fprintf(stderr, "stop=%p\n", (p)->stop); \ erts_fprintf(stderr, "htop=%p\n", (p)->htop); \ erts_fprintf(stderr, "heap=%p\n", (p)->heap); \ erl_exit(ERTS_ABORT_EXIT, "%s, line %d: %T: Overrun stack and heap\n", \ __FILE__,__LINE__,(P)->common.id); \ } #ifdef DEBUG #define ErtsGcQuickSanityCheck(P) \ do { \ ASSERT((P)->heap < (P)->hend); \ ASSERT((p)->abandoned_heap || (P)->heap_sz == (P)->hend - (P)->heap); \ ASSERT((P)->heap <= (P)->htop && (P)->htop <= (P)->hend); \ ASSERT((P)->heap <= (P)->stop && (P)->stop <= (P)->hend); \ ASSERT((p)->abandoned_heap || ((P)->heap <= (P)->high_water && (P)->high_water <= (P)->hend)); \ OverRunCheck((P)); \ } while (0) #else #define ErtsGcQuickSanityCheck(P) \ do { \ OverRunCheck((P)); \ } while (0) #endif /* * This structure describes the rootset for the GC. */ typedef struct roots { Eterm* v; /* Pointers to vectors with terms to GC * (e.g. the stack). */ Uint sz; /* Size of each vector. */ } Roots; typedef struct { Roots def[32]; /* Default storage. */ Roots* roots; /* Pointer to root set array. */ Uint size; /* Storage size. */ int num_roots; /* Number of root arrays. */ } Rootset; static Uint setup_rootset(Process*, Eterm*, int, Rootset*); static void cleanup_rootset(Rootset *rootset); static void remove_message_buffers(Process* p); static Eterm *full_sweep_heaps(Process *p, int hibernate, Eterm *n_heap, Eterm* n_htop, char *oh, Uint oh_size, Eterm *objv, int nobj); static int garbage_collect(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj); static int major_collection(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj, Uint *recl); static int minor_collection(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj, Uint *recl); static void do_minor(Process *p, ErlHeapFragment *live_hf_end, char *mature, Uint mature_size, Uint new_sz, Eterm* objv, int nobj); static Eterm *sweep_new_heap(Eterm *n_hp, Eterm *n_htop, char* old_heap, Uint old_heap_size); static Eterm *sweep_heaps(Eterm *n_hp, Eterm *n_htop, char* old_heap, Uint old_heap_size); static Eterm* sweep_literal_area(Eterm* n_hp, Eterm* n_htop, char* old_heap, Uint old_heap_size, char* src, Uint src_size); static Eterm* sweep_literals_to_old_heap(Eterm* heap_ptr, Eterm* heap_end, Eterm* htop, char* src, Uint src_size); static Eterm* collect_live_heap_frags(Process* p, ErlHeapFragment *live_hf_end, Eterm* heap, Eterm* htop, Eterm* objv, int nobj); static void adjust_after_fullsweep(Process *p, int need, Eterm *objv, int nobj); static void shrink_new_heap(Process *p, Uint new_sz, Eterm *objv, int nobj); static void grow_new_heap(Process *p, Uint new_sz, Eterm* objv, int nobj); static void sweep_off_heap(Process *p, int fullsweep); static void offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size); static void offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size); static void offset_rootset(Process *p, Sint offs, char* area, Uint area_size, Eterm* objv, int nobj); static void offset_off_heap(Process* p, Sint offs, char* area, Uint area_size); static void offset_mqueue(Process *p, Sint offs, char* area, Uint area_size); static void init_gc_info(ErtsGCInfo *gcip); #ifdef HARDDEBUG static void disallow_heap_frag_ref_in_heap(Process* p); static void disallow_heap_frag_ref_in_old_heap(Process* p); #endif #if defined(ARCH_64) # define MAX_HEAP_SIZES 154 #else # define MAX_HEAP_SIZES 59 #endif static Sint heap_sizes[MAX_HEAP_SIZES]; /* Suitable heap sizes. */ static int num_heap_sizes; /* Number of heap sizes. */ Uint erts_test_long_gc_sleep; /* Only used for testing... */ typedef struct { Process *proc; Eterm ref; Eterm ref_heap[REF_THING_SIZE]; Uint req_sched; erts_smp_atomic32_t refc; } ErtsGCInfoReq; ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(gcireq, ErtsGCInfoReq, 5, ERTS_ALC_T_GC_INFO_REQ) /* * Initialize GC global data. */ void erts_init_gc(void) { int i = 0, ix; Sint max_heap_size = 0; ERTS_CT_ASSERT(offsetof(ProcBin,thing_word) == offsetof(struct erl_off_heap_header,thing_word)); ERTS_CT_ASSERT(offsetof(ProcBin,thing_word) == offsetof(ErlFunThing,thing_word)); ERTS_CT_ASSERT(offsetof(ProcBin,thing_word) == offsetof(ExternalThing,header)); ERTS_CT_ASSERT(offsetof(ProcBin,size) == offsetof(struct erl_off_heap_header,size)); ERTS_CT_ASSERT(offsetof(ProcBin,size) == offsetof(ErlSubBin,size)); ERTS_CT_ASSERT(offsetof(ProcBin,size) == offsetof(ErlHeapBin,size)); ERTS_CT_ASSERT(offsetof(ProcBin,next) == offsetof(struct erl_off_heap_header,next)); ERTS_CT_ASSERT(offsetof(ProcBin,next) == offsetof(ErlFunThing,next)); ERTS_CT_ASSERT(offsetof(ProcBin,next) == offsetof(ExternalThing,next)); erts_test_long_gc_sleep = 0; /* * Heap sizes start growing in a Fibonacci sequence. * * Fib growth is not really ok for really large heaps, for * example is fib(35) == 14meg, whereas fib(36) == 24meg; * we really don't want that growth when the heaps are that big. */ /* Growth stage 1 - Fibonacci + 1*/ /* 12,38 will hit size 233, the old default */ heap_sizes[0] = 12; heap_sizes[1] = 38; for(i = 2; i < 23; i++) { /* one extra word for block header */ heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-2] + 1; } /* for 32 bit we want max_heap_size to be MAX(32bit) / 4 [words] * for 64 bit we want max_heap_size to be MAX(52bit) / 8 [words] */ max_heap_size = sizeof(Eterm) < 8 ? (Sint)((~(Uint)0)/(sizeof(Eterm))) : (Sint)(((Uint64)1 << 53)/sizeof(Eterm)); /* Growth stage 2 - 20% growth */ /* At 1.3 mega words heap, we start to slow down. */ for (i = 23; i < ALENGTH(heap_sizes); i++) { heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-1]/5; if ((heap_sizes[i] < 0) || heap_sizes[i] > max_heap_size) { /* Size turned negative. Discard this last size. */ i--; break; } } num_heap_sizes = i; for (ix = 0; ix < erts_no_schedulers; ix++) { ErtsSchedulerData *esdp = ERTS_SCHEDULER_IX(ix); init_gc_info(&esdp->gc_info); } init_gcireq_alloc(); } /* * Find the next heap size equal to or greater than the given size (if offset == 0). * * If offset is 1, the next higher heap size is returned (always greater than size). */ Uint erts_next_heap_size(Uint size, Uint offset) { if (size < heap_sizes[0]) { return heap_sizes[0]; } else { Sint* low = heap_sizes; Sint* high = heap_sizes + num_heap_sizes; Sint* mid; while (low < high) { mid = low + (high-low) / 2; if (size < mid[0]) { high = mid; } else if (size == mid[0]) { ASSERT(mid+offset-heap_sizes < num_heap_sizes); return mid[offset]; } else if (size < mid[1]) { ASSERT(mid[0] < size && size <= mid[1]); ASSERT(mid+offset-heap_sizes < num_heap_sizes); return mid[offset+1]; } else { low = mid + 1; } } erl_exit(1, "no next heap size found: %beu, offset %beu\n", size, offset); } return 0; } /* * Return the next heap size to use. Make sure we never return * a smaller heap size than the minimum heap size for the process. * (Use of the erlang:hibernate/3 BIF could have shrinked the * heap below the minimum heap size.) */ static Uint next_heap_size(Process* p, Uint size, Uint offset) { size = erts_next_heap_size(size, offset); return size < p->min_heap_size ? p->min_heap_size : size; } Eterm erts_heap_sizes(Process* p) { int i; int n = 0; int big = 0; Eterm res = NIL; Eterm* hp; Eterm* bigp; for (i = num_heap_sizes-1; i >= 0; i--) { n += 2; if (!MY_IS_SSMALL(heap_sizes[i])) { big += BIG_UINT_HEAP_SIZE; } } /* * We store all big numbers first on the heap, followed * by all the cons cells. */ bigp = HAlloc(p, n+big); hp = bigp+big; for (i = num_heap_sizes-1; i >= 0; i--) { Eterm num; Sint sz = heap_sizes[i]; if (MY_IS_SSMALL(sz)) { num = make_small(sz); } else { num = uint_to_big(sz, bigp); bigp += BIG_UINT_HEAP_SIZE; } res = CONS(hp, num, res); hp += 2; } return res; } void erts_offset_heap(Eterm* hp, Uint sz, Sint offs, Eterm* low, Eterm* high) { offset_heap(hp, sz, offs, (char*) low, ((char *)high)-((char *)low)); } void erts_offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, Eterm* low, Eterm* high) { offset_heap_ptr(hp, sz, offs, (char *) low, ((char *)high)-((char *)low)); } #define ptr_within(ptr, low, high) ((ptr) < (high) && (ptr) >= (low)) void erts_offset_off_heap(ErlOffHeap *ohp, Sint offs, Eterm* low, Eterm* high) { if (ohp->first && ptr_within((Eterm *)ohp->first, low, high)) { Eterm** uptr = (Eterm**) (void *) &ohp->first; *uptr += offs; } } #undef ptr_within Eterm erts_gc_after_bif_call_lhf(Process* p, ErlHeapFragment *live_hf_end, Eterm result, Eterm* regs, Uint arity) { int cost; if (p->flags & F_HIBERNATE_SCHED) { /* * We just hibernated. We do *not* want to mess * up the hibernation by an ordinary GC... */ return result; } if (is_non_value(result)) { if (p->freason == TRAP) { #if HIPE if (regs == NULL) { regs = ERTS_PROC_GET_SCHDATA(p)->x_reg_array; } #endif cost = garbage_collect(p, live_hf_end, 0, regs, p->arity); } else { cost = garbage_collect(p, live_hf_end, 0, regs, arity); } } else { Eterm val[1]; val[0] = result; cost = garbage_collect(p, live_hf_end, 0, val, 1); result = val[0]; } BUMP_REDS(p, cost); return result; } Eterm erts_gc_after_bif_call(Process* p, Eterm result, Eterm* regs, Uint arity) { return erts_gc_after_bif_call_lhf(p, ERTS_INVALID_HFRAG_PTR, result, regs, arity); } static ERTS_INLINE void reset_active_writer(Process *p) { struct erl_off_heap_header* ptr; ptr = MSO(p).first; while (ptr) { if (ptr->thing_word == HEADER_PROC_BIN) { ProcBin *pbp = (ProcBin*) ptr; pbp->flags &= ~PB_ACTIVE_WRITER; } ptr = ptr->next; } } #define ERTS_DELAY_GC_EXTRA_FREE 40 static int delay_garbage_collection(Process *p, ErlHeapFragment *live_hf_end, int need) { ErlHeapFragment *hfrag; Eterm *orig_heap, *orig_hend, *orig_htop, *orig_stop; Eterm *stop, *hend; Uint hsz, ssz; ERTS_HOLE_CHECK(p); if (p->live_hf_end == ERTS_INVALID_HFRAG_PTR) p->live_hf_end = live_hf_end; if (need == 0) return 1; /* * Satisfy need in a heap fragment... */ ASSERT(need > 0); orig_heap = p->heap; orig_hend = p->hend; orig_htop = p->htop; orig_stop = p->stop; ssz = orig_hend - orig_stop; hsz = ssz + need + ERTS_DELAY_GC_EXTRA_FREE; hfrag = new_message_buffer(hsz); hfrag->next = p->mbuf; p->mbuf = hfrag; p->mbuf_sz += hsz; p->heap = p->htop = &hfrag->mem[0]; p->hend = hend = &hfrag->mem[hsz]; p->stop = stop = hend - ssz; sys_memcpy((void *) stop, (void *) orig_stop, ssz * sizeof(Eterm)); if (p->abandoned_heap) { /* Active heap already in a fragment; adjust it... */ ErlHeapFragment *hfrag = ((ErlHeapFragment *) (((char *) orig_heap) - offsetof(ErlHeapFragment, mem))); Uint unused = orig_hend - orig_htop; ASSERT(hfrag->used_size == hfrag->alloc_size); ASSERT(hfrag->used_size >= unused); hfrag->used_size -= unused; p->mbuf_sz -= unused; } else { /* Do not leave a hole in the abandoned heap... */ if (orig_htop < orig_hend) { *orig_htop = make_pos_bignum_header(orig_hend-orig_htop-1); if (orig_htop + 1 < orig_hend) { orig_hend[-1] = (Uint) (orig_htop - orig_heap); p->flags |= F_ABANDONED_HEAP_USE; } } p->abandoned_heap = orig_heap; } #ifdef CHECK_FOR_HOLES p->last_htop = p->htop; p->heap_hfrag = hfrag; #endif /* Make sure that we do a proper GC as soon as possible... */ p->flags |= F_FORCE_GC; return CONTEXT_REDS; } static ERTS_FORCE_INLINE Uint young_gen_usage(Process *p) { Uint hsz; Eterm *aheap; hsz = p->mbuf_sz; aheap = p->abandoned_heap; if (!aheap) hsz += p->htop - p->heap; else { /* used in orig heap */ if (p->flags & F_ABANDONED_HEAP_USE) hsz += aheap[p->heap_sz-1]; else hsz += p->heap_sz; /* Remove unused part in latest fragment */ hsz -= p->hend - p->htop; } return hsz; } #define ERTS_GET_ORIG_HEAP(Proc, Heap, HTop) \ do { \ Eterm *aheap__ = (Proc)->abandoned_heap; \ if (!aheap__) { \ (Heap) = (Proc)->heap; \ (HTop) = (Proc)->htop; \ } \ else { \ (Heap) = aheap__; \ if ((Proc)->flags & F_ABANDONED_HEAP_USE) \ (HTop) = aheap__ + aheap__[(Proc)->heap_sz-1]; \ else \ (HTop) = aheap__ + (Proc)->heap_sz; \ } \ } while (0) /* * Garbage collect a process. * * p: Pointer to the process structure. * need: Number of Eterm words needed on the heap. * objv: Array of terms to add to rootset; that is to preserve. * nobj: Number of objects in objv. */ static int garbage_collect(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj) { Uint reclaimed_now = 0; int done = 0; ErtsMonotonicTime start_time = 0; /* Shut up faulty warning... */ ErtsSchedulerData *esdp; #ifdef USE_VM_PROBES DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE); #endif if (p->flags & F_DISABLE_GC) return delay_garbage_collection(p, live_hf_end, need); if (p->live_hf_end != ERTS_INVALID_HFRAG_PTR) live_hf_end = p->live_hf_end; esdp = erts_get_scheduler_data(); if (IS_TRACED_FL(p, F_TRACE_GC)) { trace_gc(p, am_gc_start); } erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC); if (erts_system_monitor_long_gc != 0) start_time = erts_get_monotonic_time(esdp); ERTS_CHK_OFFHEAP(p); ErtsGcQuickSanityCheck(p); if (GEN_GCS(p) >= MAX_GEN_GCS(p)) { FLAGS(p) |= F_NEED_FULLSWEEP; } #ifdef USE_VM_PROBES *pidbuf = '\0'; if (DTRACE_ENABLED(gc_major_start) || DTRACE_ENABLED(gc_major_end) || DTRACE_ENABLED(gc_minor_start) || DTRACE_ENABLED(gc_minor_end)) { dtrace_proc_str(p, pidbuf); } #endif /* * Test which type of GC to do. */ while (!done) { if ((FLAGS(p) & F_NEED_FULLSWEEP) != 0) { DTRACE2(gc_major_start, pidbuf, need); done = major_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now); DTRACE2(gc_major_end, pidbuf, reclaimed_now); } else { DTRACE2(gc_minor_start, pidbuf, need); done = minor_collection(p, live_hf_end, need, objv, nobj, &reclaimed_now); DTRACE2(gc_minor_end, pidbuf, reclaimed_now); } } reset_active_writer(p); /* * Finish. */ ERTS_CHK_OFFHEAP(p); ErtsGcQuickSanityCheck(p); erts_smp_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_GC); if (IS_TRACED_FL(p, F_TRACE_GC)) { trace_gc(p, am_gc_end); } if (erts_system_monitor_long_gc != 0) { ErtsMonotonicTime end_time; Uint gc_time; if (erts_test_long_gc_sleep) while (0 != erts_milli_sleep(erts_test_long_gc_sleep)); end_time = erts_get_monotonic_time(esdp); gc_time = (Uint) ERTS_MONOTONIC_TO_MSEC(end_time - start_time); if (gc_time && gc_time > erts_system_monitor_long_gc) { monitor_long_gc(p, gc_time); } } if (erts_system_monitor_large_heap != 0) { Uint size = HEAP_SIZE(p); size += OLD_HEAP(p) ? OLD_HEND(p) - OLD_HEAP(p) : 0; if (size >= erts_system_monitor_large_heap) monitor_large_heap(p); } esdp->gc_info.garbage_cols++; esdp->gc_info.reclaimed += reclaimed_now; FLAGS(p) &= ~F_FORCE_GC; p->live_hf_end = ERTS_INVALID_HFRAG_PTR; #ifdef CHECK_FOR_HOLES /* * We intentionally do not rescan the areas copied by the GC. * We trust the GC not to leave any holes. */ p->last_htop = p->htop; p->last_mbuf = 0; #endif #ifdef DEBUG /* * The scanning for pointers from the old_heap into the new_heap or * heap fragments turned out to be costly, so we remember how far we * have scanned this time and will start scanning there next time. * (We will not detect wild writes into the old heap, or modifications * of the old heap in-between garbage collections.) */ p->last_old_htop = p->old_htop; #endif /* FIXME: This function should really return an Sint, i.e., a possibly 64 bit wide signed integer, but that requires updating all the code that calls it. For now, we just return INT_MAX if the result is too large for an int. */ { Sint result = (HEAP_TOP(p) - HEAP_START(p)) / 10; if (result >= INT_MAX) return INT_MAX; else return (int) result; } } int erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj) { return garbage_collect(p, ERTS_INVALID_HFRAG_PTR, need, objv, nobj); } /* * Place all living data on a the new heap; deallocate any old heap. * Meant to be used by hibernate/3. */ void erts_garbage_collect_hibernate(Process* p) { Uint heap_size; Eterm* heap; Eterm* htop; Uint actual_size; char* area; Uint area_size; Sint offs; if (p->flags & F_DISABLE_GC) ERTS_INTERNAL_ERROR("GC disabled"); /* * Preliminaries. */ erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC); ErtsGcQuickSanityCheck(p); ASSERT(p->mbuf == NULL); ASSERT(p->stop == p->hend); /* Stack must be empty. */ ASSERT(!p->abandoned_heap); /* * Do it. */ heap_size = p->heap_sz + (p->old_htop - p->old_heap) + p->mbuf_sz; heap = (Eterm*) ERTS_HEAP_ALLOC(ERTS_ALC_T_TMP_HEAP, sizeof(Eterm)*heap_size); htop = heap; htop = full_sweep_heaps(p, 1, heap, htop, (char *) p->old_heap, (char *) p->old_htop - (char *) p->old_heap, p->arg_reg, p->arity); p->heap = heap; p->high_water = htop; p->htop = htop; p->hend = p->heap + heap_size; p->stop = p->hend; p->heap_sz = heap_size; heap_size = actual_size = p->htop - p->heap; if (heap_size == 0) { heap_size = 1; /* We want a heap... */ } FLAGS(p) &= ~F_FORCE_GC; p->live_hf_end = ERTS_INVALID_HFRAG_PTR; /* * Move the heap to its final destination. * * IMPORTANT: We have garbage collected to a temporary heap and * then copy the result to a newly allocated heap of exact size. * This is intentional and important! Garbage collecting as usual * and then shrinking the heap by reallocating it caused serious * fragmentation problems when large amounts of processes were * hibernated. */ ASSERT(p->hend - p->stop == 0); /* Empty stack */ ASSERT(actual_size < p->heap_sz); heap = ERTS_HEAP_ALLOC(ERTS_ALC_T_HEAP, sizeof(Eterm)*heap_size); sys_memcpy((void *) heap, (void *) p->heap, actual_size*sizeof(Eterm)); ERTS_HEAP_FREE(ERTS_ALC_T_TMP_HEAP, p->heap, p->heap_sz*sizeof(Eterm)); remove_message_buffers(p); p->stop = p->hend = heap + heap_size; offs = heap - p->heap; area = (char *) p->heap; area_size = ((char *) p->htop) - area; offset_heap(heap, actual_size, offs, area, area_size); p->high_water = heap + (p->high_water - p->heap); offset_rootset(p, offs, area, area_size, p->arg_reg, p->arity); p->htop = heap + actual_size; p->heap = heap; p->heap_sz = heap_size; #ifdef CHECK_FOR_HOLES p->last_htop = p->htop; p->last_mbuf = 0; #endif #ifdef DEBUG p->last_old_htop = NULL; #endif /* * Finishing. */ ErtsGcQuickSanityCheck(p); erts_smp_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_GC); } void erts_garbage_collect_literals(Process* p, Eterm* literals, Uint byte_lit_size, struct erl_off_heap_header* oh) { Uint lit_size = byte_lit_size / sizeof(Eterm); Uint old_heap_size; Eterm* temp_lit; Sint offs; Rootset rootset; /* Rootset for GC (stack, dictionary, etc). */ Roots* roots; char* area; Uint area_size; Eterm* old_htop; Uint n; struct erl_off_heap_header** prev = NULL; if (p->flags & F_DISABLE_GC) return; /* * Set GC state. */ erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC); /* * We assume that the caller has already done a major collection * (which has discarded the old heap), so that we don't have to cope * with pointer to literals on the old heap. We will now allocate * an old heap to contain the literals. */ ASSERT(p->old_heap == 0); /* Must NOT have an old heap yet. */ old_heap_size = erts_next_heap_size(lit_size, 0); p->old_heap = p->old_htop = (Eterm*) ERTS_HEAP_ALLOC(ERTS_ALC_T_OLD_HEAP, sizeof(Eterm)*old_heap_size); p->old_hend = p->old_heap + old_heap_size; /* * We soon want to garbage collect the literals. But since a GC is * destructive (MOVED markers are written), we must copy the literals * to a temporary area and change all references to literals. */ temp_lit = (Eterm *) erts_alloc(ERTS_ALC_T_TMP, byte_lit_size); sys_memcpy(temp_lit, literals, byte_lit_size); offs = temp_lit - literals; offset_heap(temp_lit, lit_size, offs, (char *) literals, byte_lit_size); offset_heap(p->heap, p->htop - p->heap, offs, (char *) literals, byte_lit_size); offset_rootset(p, offs, (char *) literals, byte_lit_size, p->arg_reg, p->arity); if (oh) { oh = (struct erl_off_heap_header *) ((Eterm *)(void *) oh + offs); } /* * Now the literals are placed in memory that is safe to write into, * so now we GC the literals into the old heap. First we go through the * rootset. */ area = (char *) temp_lit; area_size = byte_lit_size; n = setup_rootset(p, p->arg_reg, p->arity, &rootset); roots = rootset.roots; old_htop = p->old_htop; while (n--) { Eterm* g_ptr = roots->v; Uint g_sz = roots->sz; Eterm* ptr; Eterm val; roots++; while (g_sz--) { Eterm gval = *g_ptr; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *g_ptr++ = val; } else if (ErtsInArea(ptr, area, area_size)) { MOVE_BOXED(ptr,val,old_htop,g_ptr++); } else { g_ptr++; } break; case TAG_PRIMARY_LIST: ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { /* Moved */ *g_ptr++ = ptr[1]; } else if (ErtsInArea(ptr, area, area_size)) { MOVE_CONS(ptr,val,old_htop,g_ptr++); } else { g_ptr++; } break; default: g_ptr++; break; } } } ASSERT(p->old_htop <= old_htop && old_htop <= p->old_hend); cleanup_rootset(&rootset); /* * Now all references in the rootset to the literals have been updated. * Now we'll have to go through all heaps updating all other references. */ old_htop = sweep_literals_to_old_heap(p->heap, p->htop, old_htop, area, area_size); old_htop = sweep_literal_area(p->old_heap, old_htop, (char *) p->old_heap, sizeof(Eterm)*old_heap_size, area, area_size); ASSERT(p->old_htop <= old_htop && old_htop <= p->old_hend); p->old_htop = old_htop; /* * Prepare to sweep binaries. Since all MSOs on the new heap * must be come before MSOs on the old heap, find the end of * current MSO list and use that as a starting point. */ if (oh) { prev = &MSO(p).first; while (*prev) { prev = &(*prev)->next; } } /* * Sweep through all binaries in the temporary literal area. */ while (oh) { if (IS_MOVED_BOXED(oh->thing_word)) { Binary* bptr; struct erl_off_heap_header* ptr; ptr = (struct erl_off_heap_header*) boxed_val(oh->thing_word); ASSERT(thing_subtag(ptr->thing_word) == REFC_BINARY_SUBTAG); bptr = ((ProcBin*)ptr)->val; /* * This binary has been copied to the heap. * We must increment its reference count and * link it into the MSO list for the process. */ erts_refc_inc(&bptr->refc, 1); *prev = ptr; prev = &ptr->next; } oh = oh->next; } if (prev) { *prev = NULL; } /* * We no longer need this temporary area. */ erts_free(ERTS_ALC_T_TMP, (void *) temp_lit); /* * Restore status. */ erts_smp_atomic32_read_band_nob(&p->state, ~ERTS_PSFLG_GC); } static int minor_collection(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj, Uint *recl) { Eterm *mature = p->abandoned_heap ? p->abandoned_heap : p->heap; Uint mature_size = p->high_water - mature; Uint size_before = young_gen_usage(p); /* * Allocate an old heap if we don't have one and if we'll need one. */ if (OLD_HEAP(p) == NULL && mature_size != 0) { Eterm* n_old; /* Note: We choose a larger heap size than strictly needed, * which seems to reduce the number of fullsweeps. * This improved Estone by more than 1200 estones on my computer * (Ultra Sparc 10). */ Uint new_sz = erts_next_heap_size(size_before, 1); /* Create new, empty old_heap */ n_old = (Eterm *) ERTS_HEAP_ALLOC(ERTS_ALC_T_OLD_HEAP, sizeof(Eterm)*new_sz); OLD_HEND(p) = n_old + new_sz; OLD_HEAP(p) = OLD_HTOP(p) = n_old; } /* * Do a minor collection if there is an old heap and if it * is large enough. */ if (OLD_HEAP(p) && ((mature_size <= OLD_HEND(p) - OLD_HTOP(p)) && ((BIN_OLD_VHEAP_SZ(p) > BIN_OLD_VHEAP(p))) ) ) { Uint stack_size, size_after, need_after, new_sz; stack_size = p->hend - p->stop; new_sz = stack_size + size_before; new_sz = next_heap_size(p, new_sz, 0); do_minor(p, live_hf_end, (char *) mature, mature_size*sizeof(Eterm), new_sz, objv, nobj); size_after = HEAP_TOP(p) - HEAP_START(p); *recl += (size_before - size_after); ErtsGcQuickSanityCheck(p); GEN_GCS(p)++; need_after = ((HEAP_TOP(p) - HEAP_START(p)) + need + stack_size); /* * Excessively large heaps should be shrunk, but * don't even bother on reasonable small heaps. * * The reason for this is that after tenuring, we often * use a really small portion of new heap, therefore, unless * the heap size is substantial, we don't want to shrink. */ if ((HEAP_SIZE(p) > 3000) && (4 * need_after < HEAP_SIZE(p)) && ((HEAP_SIZE(p) > 8000) || (HEAP_SIZE(p) > (OLD_HEND(p) - OLD_HEAP(p))))) { Uint wanted = 3 * need_after; Uint old_heap_sz = OLD_HEND(p) - OLD_HEAP(p); /* * Additional test to make sure we don't make the heap too small * compared to the size of the older generation heap. */ if (wanted*9 < old_heap_sz) { Uint new_wanted = old_heap_sz / 8; if (new_wanted > wanted) { wanted = new_wanted; } } wanted = wanted < MIN_HEAP_SIZE(p) ? MIN_HEAP_SIZE(p) : next_heap_size(p, wanted, 0); if (wanted < HEAP_SIZE(p)) { shrink_new_heap(p, wanted, objv, nobj); } ASSERT(HEAP_SIZE(p) == next_heap_size(p, HEAP_SIZE(p), 0)); ASSERT(MBUF(p) == NULL); return 1; /* We are done. */ } if (HEAP_SIZE(p) >= need_after) { /* * The heap size turned out to be just right. We are done. */ ASSERT(HEAP_SIZE(p) == next_heap_size(p, HEAP_SIZE(p), 0)); ASSERT(MBUF(p) == NULL); return 1; } grow_new_heap(p, next_heap_size(p, need_after, 0), objv, nobj); return 1; } /* * Not enough room for a minor collection. Must force a major collection. */ FLAGS(p) |= F_NEED_FULLSWEEP; return 0; } /* * HiPE native code stack scanning procedures: * - fullsweep_nstack() * - gensweep_nstack() * - offset_nstack() */ #if defined(HIPE) #define GENSWEEP_NSTACK(p,old_htop,n_htop) \ do { \ Eterm *tmp_old_htop = old_htop; \ Eterm *tmp_n_htop = n_htop; \ gensweep_nstack((p), &tmp_old_htop, &tmp_n_htop); \ old_htop = tmp_old_htop; \ n_htop = tmp_n_htop; \ } while(0) /* * offset_nstack() can ignore the descriptor-based traversal the other * nstack procedures use and simply call offset_heap_ptr() instead. * This relies on two facts: * 1. The only live non-Erlang terms on an nstack are return addresses, * and they will be skipped thanks to the low/high range check. * 2. Dead values, even if mistaken for pointers into the low/high area, * can be offset safely since they won't be dereferenced. * * XXX: WARNING: If HiPE starts storing other non-Erlang values on the * nstack, such as floats, then this will have to be changed. */ static ERTS_INLINE void offset_nstack(Process* p, Sint offs, char* area, Uint area_size) { if (p->hipe.nstack) { ASSERT(p->hipe.nsp && p->hipe.nstend); offset_heap_ptr(hipe_nstack_start(p), hipe_nstack_used(p), offs, area, area_size); } else { ASSERT(!p->hipe.nsp && !p->hipe.nstend); } } #else /* !HIPE */ #define fullsweep_nstack(p,n_htop) (n_htop) #define GENSWEEP_NSTACK(p,old_htop,n_htop) do{}while(0) #define offset_nstack(p,offs,area,area_size) do{}while(0) #endif /* HIPE */ static void do_minor(Process *p, ErlHeapFragment *live_hf_end, char *mature, Uint mature_size, Uint new_sz, Eterm* objv, int nobj) { Rootset rootset; /* Rootset for GC (stack, dictionary, etc). */ Roots* roots; Eterm* n_htop; Uint n; Eterm* ptr; Eterm val; Eterm gval; Eterm* old_htop = OLD_HTOP(p); Eterm* n_heap; char* oh = (char *) OLD_HEAP(p); Uint oh_size = (char *) OLD_HTOP(p) - oh; n_htop = n_heap = (Eterm*) ERTS_HEAP_ALLOC(ERTS_ALC_T_HEAP, sizeof(Eterm)*new_sz); if (live_hf_end != ERTS_INVALID_HFRAG_PTR) { /* * Move heap frags that we know are completely live * directly into the new young heap generation. */ n_htop = collect_live_heap_frags(p, live_hf_end, n_heap, n_htop, objv, nobj); } n = setup_rootset(p, objv, nobj, &rootset); roots = rootset.roots; GENSWEEP_NSTACK(p, old_htop, n_htop); while (n--) { Eterm* g_ptr = roots->v; Uint g_sz = roots->sz; roots++; while (g_sz--) { gval = *g_ptr; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: { ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *g_ptr++ = val; } else if (ErtsInArea(ptr, mature, mature_size)) { MOVE_BOXED(ptr,val,old_htop,g_ptr++); } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) { MOVE_BOXED(ptr,val,n_htop,g_ptr++); } else { g_ptr++; } break; } case TAG_PRIMARY_LIST: { ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { /* Moved */ *g_ptr++ = ptr[1]; } else if (ErtsInArea(ptr, mature, mature_size)) { MOVE_CONS(ptr,val,old_htop,g_ptr++); } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) { MOVE_CONS(ptr,val,n_htop,g_ptr++); } else { g_ptr++; } break; } default: g_ptr++; break; } } } cleanup_rootset(&rootset); /* * Now all references in the rootset point to the new heap. However, * most references on the new heap point to the old heap so the next stage * is to scan through the new heap evacuating data from the old heap * until all is changed. */ if (mature_size == 0) { n_htop = sweep_new_heap(n_heap, n_htop, oh, oh_size); } else { Eterm* n_hp = n_heap; Eterm* ptr; Eterm val; Eterm gval; while (n_hp != n_htop) { ASSERT(n_hp < n_htop); gval = *n_hp; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: { ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *n_hp++ = val; } else if (ErtsInArea(ptr, mature, mature_size)) { MOVE_BOXED(ptr,val,old_htop,n_hp++); } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) { MOVE_BOXED(ptr,val,n_htop,n_hp++); } else { n_hp++; } break; } case TAG_PRIMARY_LIST: { ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { *n_hp++ = ptr[1]; } else if (ErtsInArea(ptr, mature, mature_size)) { MOVE_CONS(ptr,val,old_htop,n_hp++); } else if (ErtsInYoungGen(gval, ptr, oh, oh_size)) { MOVE_CONS(ptr,val,n_htop,n_hp++); } else { n_hp++; } break; } case TAG_PRIMARY_HEADER: { if (!header_is_thing(gval)) n_hp++; else { if (header_is_bin_matchstate(gval)) { ErlBinMatchState *ms = (ErlBinMatchState*) n_hp; ErlBinMatchBuffer *mb = &(ms->mb); Eterm* origptr = &(mb->orig); ptr = boxed_val(*origptr); val = *ptr; if (IS_MOVED_BOXED(val)) { *origptr = val; mb->base = binary_bytes(val); } else if (ErtsInArea(ptr, mature, mature_size)) { MOVE_BOXED(ptr,val,old_htop,origptr); mb->base = binary_bytes(mb->orig); } else if (ErtsInYoungGen(*origptr, ptr, oh, oh_size)) { MOVE_BOXED(ptr,val,n_htop,origptr); mb->base = binary_bytes(mb->orig); } } n_hp += (thing_arityval(gval)+1); } break; } default: n_hp++; break; } } } /* * And also if we have been tenuring, references on the second generation * may point to the old (soon to be deleted) new_heap. */ if (OLD_HTOP(p) < old_htop) old_htop = sweep_new_heap(OLD_HTOP(p), old_htop, oh, oh_size); OLD_HTOP(p) = old_htop; HIGH_WATER(p) = n_htop; if (MSO(p).first) { sweep_off_heap(p, 0); } #ifdef HARDDEBUG /* * Go through the old_heap before, and try to find references from the old_heap * into the old new_heap that has just been evacuated and is about to be freed * (as well as looking for reference into heap fragments, of course). */ disallow_heap_frag_ref_in_old_heap(p); #endif /* Copy stack to end of new heap */ n = p->hend - p->stop; sys_memcpy(n_heap + new_sz - n, p->stop, n * sizeof(Eterm)); p->stop = n_heap + new_sz - n; #ifdef USE_VM_PROBES if (HEAP_SIZE(p) != new_sz && DTRACE_ENABLED(process_heap_grow)) { DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE); dtrace_proc_str(p, pidbuf); DTRACE3(process_heap_grow, pidbuf, HEAP_SIZE(p), new_sz); } #endif ERTS_HEAP_FREE(ERTS_ALC_T_HEAP, (p->abandoned_heap ? p->abandoned_heap : HEAP_START(p)), HEAP_SIZE(p) * sizeof(Eterm)); p->abandoned_heap = NULL; p->flags &= ~F_ABANDONED_HEAP_USE; HEAP_START(p) = n_heap; HEAP_TOP(p) = n_htop; HEAP_SIZE(p) = new_sz; HEAP_END(p) = n_heap + new_sz; #ifdef HARDDEBUG disallow_heap_frag_ref_in_heap(p); #endif remove_message_buffers(p); } /* * Major collection. DISCARD the old heap. */ static int major_collection(Process* p, ErlHeapFragment *live_hf_end, int need, Eterm* objv, int nobj, Uint *recl) { Uint size_before, stack_size; Eterm* n_heap; Eterm* n_htop; char* oh = (char *) OLD_HEAP(p); Uint oh_size = (char *) OLD_HTOP(p) - oh; Uint new_sz, stk_sz; /* * Do a fullsweep GC. First figure out the size of the heap * to receive all live data. */ size_before = young_gen_usage(p); size_before += p->old_htop - p->old_heap; stack_size = p->hend - p->stop; new_sz = stack_size + size_before; new_sz = next_heap_size(p, new_sz, 0); /* * Should we grow although we don't actually need to? */ if (new_sz == HEAP_SIZE(p) && FLAGS(p) & F_HEAP_GROW) { new_sz = next_heap_size(p, HEAP_SIZE(p), 1); } FLAGS(p) &= ~(F_HEAP_GROW|F_NEED_FULLSWEEP); n_htop = n_heap = (Eterm *) ERTS_HEAP_ALLOC(ERTS_ALC_T_HEAP, sizeof(Eterm)*new_sz); if (live_hf_end != ERTS_INVALID_HFRAG_PTR) { /* * Move heap frags that we know are completely live * directly into the heap. */ n_htop = collect_live_heap_frags(p, live_hf_end, n_heap, n_htop, objv, nobj); } n_htop = full_sweep_heaps(p, 0, n_heap, n_htop, oh, oh_size, objv, nobj); /* Move the stack to the end of the heap */ stk_sz = HEAP_END(p) - p->stop; sys_memcpy(n_heap + new_sz - stk_sz, p->stop, stk_sz * sizeof(Eterm)); p->stop = n_heap + new_sz - stk_sz; #ifdef USE_VM_PROBES if (HEAP_SIZE(p) != new_sz && DTRACE_ENABLED(process_heap_grow)) { DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE); dtrace_proc_str(p, pidbuf); DTRACE3(process_heap_grow, pidbuf, HEAP_SIZE(p), new_sz); } #endif ERTS_HEAP_FREE(ERTS_ALC_T_HEAP, (p->abandoned_heap ? p->abandoned_heap : HEAP_START(p)), (HEAP_END(p) - HEAP_START(p)) * sizeof(Eterm)); p->abandoned_heap = NULL; p->flags &= ~F_ABANDONED_HEAP_USE; HEAP_START(p) = n_heap; HEAP_TOP(p) = n_htop; HEAP_SIZE(p) = new_sz; HEAP_END(p) = n_heap + new_sz; GEN_GCS(p) = 0; HIGH_WATER(p) = HEAP_TOP(p); ErtsGcQuickSanityCheck(p); *recl += size_before - (HEAP_TOP(p) - HEAP_START(p)); adjust_after_fullsweep(p, need, objv, nobj); #ifdef HARDDEBUG disallow_heap_frag_ref_in_heap(p); #endif remove_message_buffers(p); ErtsGcQuickSanityCheck(p); return 1; /* We are done. */ } static Eterm * full_sweep_heaps(Process *p, int hibernate, Eterm *n_heap, Eterm* n_htop, char *oh, Uint oh_size, Eterm *objv, int nobj) { Rootset rootset; Roots *roots; Uint n; /* * Copy all top-level terms directly referenced by the rootset to * the new new_heap. */ n = setup_rootset(p, objv, nobj, &rootset); #ifdef HIPE if (hibernate) hipe_empty_nstack(p); else n_htop = fullsweep_nstack(p, n_htop); #endif roots = rootset.roots; while (n--) { Eterm* g_ptr = roots->v; Eterm g_sz = roots->sz; roots++; while (g_sz--) { Eterm* ptr; Eterm val; Eterm gval = *g_ptr; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: { ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *g_ptr++ = val; } else if (!erts_is_literal(gval, ptr)) { MOVE_BOXED(ptr,val,n_htop,g_ptr++); } else { g_ptr++; } continue; } case TAG_PRIMARY_LIST: { ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { *g_ptr++ = ptr[1]; } else if (!erts_is_literal(gval, ptr)) { MOVE_CONS(ptr,val,n_htop,g_ptr++); } else { g_ptr++; } continue; } default: { g_ptr++; continue; } } } } cleanup_rootset(&rootset); /* * Now all references on the stack point to the new heap. However, * most references on the new heap point to the old heap so the next stage * is to scan through the new heap evacuating data from the old heap * until all is copied. */ n_htop = sweep_heaps(n_heap, n_htop, oh, oh_size); if (MSO(p).first) { sweep_off_heap(p, 1); } if (OLD_HEAP(p) != NULL) { ERTS_HEAP_FREE(ERTS_ALC_T_OLD_HEAP, OLD_HEAP(p), (OLD_HEND(p) - OLD_HEAP(p)) * sizeof(Eterm)); OLD_HEAP(p) = OLD_HTOP(p) = OLD_HEND(p) = NULL; } return n_htop; } static void adjust_after_fullsweep(Process *p, int need, Eterm *objv, int nobj) { Uint wanted, sz, need_after; Uint stack_size = STACK_SZ_ON_HEAP(p); /* * Resize the heap if needed. */ need_after = (HEAP_TOP(p) - HEAP_START(p)) + need + stack_size; if (HEAP_SIZE(p) < need_after) { /* Too small - grow to match requested need */ sz = next_heap_size(p, need_after, 0); grow_new_heap(p, sz, objv, nobj); } else if (3 * HEAP_SIZE(p) < 4 * need_after){ /* Need more than 75% of current, postpone to next GC.*/ FLAGS(p) |= F_HEAP_GROW; } else if (4 * need_after < HEAP_SIZE(p) && HEAP_SIZE(p) > H_MIN_SIZE){ /* We need less than 25% of the current heap, shrink.*/ /* XXX - This is how it was done in the old GC: wanted = 4 * need_after; I think this is better as fullsweep is used mainly on small memory systems, but I could be wrong... */ wanted = 2 * need_after; sz = wanted < p->min_heap_size ? p->min_heap_size : next_heap_size(p, wanted, 0); if (sz < HEAP_SIZE(p)) { shrink_new_heap(p, sz, objv, nobj); } } } /* * Remove all message buffers. */ static void remove_message_buffers(Process* p) { if (MBUF(p) != NULL) { free_message_buffer(MBUF(p)); MBUF(p) = NULL; } if (p->msg_frag) { erts_cleanup_messages(p->msg_frag); p->msg_frag = NULL; } MBUF_SIZE(p) = 0; } #ifdef HARDDEBUG /* * Routines to verify that we don't have pointer into heap fragments from * that are not allowed to have them. * * For performance reasons, we use _unchecked_list_val(), _unchecked_boxed_val(), * and so on to avoid a function call. */ static void disallow_heap_frag_ref_in_heap(Process* p) { Eterm* hp; Eterm* htop; Eterm* heap; Uint heap_size; if (p->mbuf == 0) { return; } htop = p->htop; heap = p->heap; heap_size = (htop - heap)*sizeof(Eterm); hp = heap; while (hp < htop) { ErlHeapFragment* qb; Eterm* ptr; Eterm val; val = *hp++; switch (primary_tag(val)) { case TAG_PRIMARY_BOXED: ptr = _unchecked_boxed_val(val); if (!ErtsInArea(ptr, heap, heap_size)) { for (qb = MBUF(p); qb != NULL; qb = qb->next) { if (ErtsInArea(ptr, qb->mem, qb->alloc_size*sizeof(Eterm))) { abort(); } } } break; case TAG_PRIMARY_LIST: ptr = _unchecked_list_val(val); if (!ErtsInArea(ptr, heap, heap_size)) { for (qb = MBUF(p); qb != NULL; qb = qb->next) { if (ErtsInArea(ptr, qb->mem, qb->alloc_size*sizeof(Eterm))) { abort(); } } } break; case TAG_PRIMARY_HEADER: if (header_is_thing(val)) { hp += _unchecked_thing_arityval(val); } break; } } } static void disallow_heap_frag_ref_in_old_heap(Process* p) { Eterm* hp; Eterm* htop; Eterm* old_heap; Uint old_heap_size; Eterm* new_heap; Uint new_heap_size; htop = p->old_htop; old_heap = p->old_heap; old_heap_size = (htop - old_heap)*sizeof(Eterm); new_heap = p->heap; new_heap_size = (p->htop - new_heap)*sizeof(Eterm); ASSERT(!p->last_old_htop || (old_heap <= p->last_old_htop && p->last_old_htop <= htop)); hp = p->last_old_htop ? p->last_old_htop : old_heap; while (hp < htop) { ErlHeapFragment* qb; Eterm* ptr; Eterm val; val = *hp++; switch (primary_tag(val)) { case TAG_PRIMARY_BOXED: ptr = (Eterm *) val; if (!ErtsInArea(ptr, old_heap, old_heap_size)) { if (ErtsInArea(ptr, new_heap, new_heap_size)) { abort(); } for (qb = MBUF(p); qb != NULL; qb = qb->next) { if (ErtsInArea(ptr, qb->mem, qb->alloc_size*sizeof(Eterm))) { abort(); } } } break; case TAG_PRIMARY_LIST: ptr = (Eterm *) val; if (!ErtsInArea(ptr, old_heap, old_heap_size)) { if (ErtsInArea(ptr, new_heap, new_heap_size)) { abort(); } for (qb = MBUF(p); qb != NULL; qb = qb->next) { if (ErtsInArea(ptr, qb->mem, qb->alloc_size*sizeof(Eterm))) { abort(); } } } break; case TAG_PRIMARY_HEADER: if (header_is_thing(val)) { hp += _unchecked_thing_arityval(val); if (!ErtsInArea(hp, old_heap, old_heap_size+1)) { abort(); } } break; } } } #endif typedef enum { ErtsSweepNewHeap, ErtsSweepHeaps, ErtsSweepLiteralArea } ErtsSweepType; static ERTS_FORCE_INLINE Eterm * sweep(Eterm *n_hp, Eterm *n_htop, ErtsSweepType type, char *oh, Uint ohsz, char *src, Uint src_size) { Eterm* ptr; Eterm val; Eterm gval; #undef ERTS_IS_IN_SWEEP_AREA #define ERTS_IS_IN_SWEEP_AREA(TPtr, Ptr) \ (type == ErtsSweepHeaps \ ? !erts_is_literal((TPtr), (Ptr)) \ : (type == ErtsSweepNewHeap \ ? ErtsInYoungGen((TPtr), (Ptr), oh, ohsz) \ : ErtsInArea((Ptr), src, src_size))) while (n_hp != n_htop) { ASSERT(n_hp < n_htop); gval = *n_hp; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: { ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *n_hp++ = val; } else if (ERTS_IS_IN_SWEEP_AREA(gval, ptr)) { MOVE_BOXED(ptr,val,n_htop,n_hp++); } else { n_hp++; } break; } case TAG_PRIMARY_LIST: { ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { *n_hp++ = ptr[1]; } else if (ERTS_IS_IN_SWEEP_AREA(gval, ptr)) { MOVE_CONS(ptr,val,n_htop,n_hp++); } else { n_hp++; } break; } case TAG_PRIMARY_HEADER: { if (!header_is_thing(gval)) { n_hp++; } else { if (header_is_bin_matchstate(gval)) { ErlBinMatchState *ms = (ErlBinMatchState*) n_hp; ErlBinMatchBuffer *mb = &(ms->mb); Eterm* origptr; origptr = &(mb->orig); ptr = boxed_val(*origptr); val = *ptr; if (IS_MOVED_BOXED(val)) { *origptr = val; mb->base = binary_bytes(*origptr); } else if (ERTS_IS_IN_SWEEP_AREA(*origptr, ptr)) { MOVE_BOXED(ptr,val,n_htop,origptr); mb->base = binary_bytes(*origptr); } } n_hp += (thing_arityval(gval)+1); } break; } default: n_hp++; break; } } return n_htop; #undef ERTS_IS_IN_SWEEP_AREA } static Eterm * sweep_new_heap(Eterm *n_hp, Eterm *n_htop, char* old_heap, Uint old_heap_size) { return sweep(n_hp, n_htop, ErtsSweepNewHeap, old_heap, old_heap_size, NULL, 0); } static Eterm * sweep_heaps(Eterm *n_hp, Eterm *n_htop, char* old_heap, Uint old_heap_size) { return sweep(n_hp, n_htop, ErtsSweepHeaps, old_heap, old_heap_size, NULL, 0); } static Eterm * sweep_literal_area(Eterm *n_hp, Eterm *n_htop, char* old_heap, Uint old_heap_size, char* src, Uint src_size) { return sweep(n_hp, n_htop, ErtsSweepLiteralArea, old_heap, old_heap_size, src, src_size); } static Eterm* sweep_literals_to_old_heap(Eterm* heap_ptr, Eterm* heap_end, Eterm* htop, char* src, Uint src_size) { while (heap_ptr < heap_end) { Eterm* ptr; Eterm val; Eterm gval = *heap_ptr; switch (primary_tag(gval)) { case TAG_PRIMARY_BOXED: { ptr = boxed_val(gval); val = *ptr; if (IS_MOVED_BOXED(val)) { ASSERT(is_boxed(val)); *heap_ptr++ = val; } else if (ErtsInArea(ptr, src, src_size)) { MOVE_BOXED(ptr,val,htop,heap_ptr++); } else { heap_ptr++; } break; } case TAG_PRIMARY_LIST: { ptr = list_val(gval); val = *ptr; if (IS_MOVED_CONS(val)) { *heap_ptr++ = ptr[1]; } else if (ErtsInArea(ptr, src, src_size)) { MOVE_CONS(ptr,val,htop,heap_ptr++); } else { heap_ptr++; } break; } case TAG_PRIMARY_HEADER: { if (!header_is_thing(gval)) { heap_ptr++; } else { if (header_is_bin_matchstate(gval)) { ErlBinMatchState *ms = (ErlBinMatchState*) heap_ptr; ErlBinMatchBuffer *mb = &(ms->mb); Eterm* origptr; origptr = &(mb->orig); ptr = boxed_val(*origptr); val = *ptr; if (IS_MOVED_BOXED(val)) { *origptr = val; mb->base = binary_bytes(*origptr); } else if (ErtsInArea(ptr, src, src_size)) { MOVE_BOXED(ptr,val,htop,origptr); mb->base = binary_bytes(*origptr); } } heap_ptr += (thing_arityval(gval)+1); } break; } default: heap_ptr++; break; } } return htop; } /* * Move an area (heap fragment) by sweeping over it and set move markers. */ static Eterm* move_one_area(Eterm* n_htop, char* src, Uint src_size) { Eterm* ptr = (Eterm*) src; Eterm* end = ptr + src_size/sizeof(Eterm); Eterm dummy_ref; while (ptr != end) { Eterm val; ASSERT(ptr < end); val = *ptr; ASSERT(val != ERTS_HOLE_MARKER); if (is_header(val)) { ASSERT(ptr + header_arity(val) < end); MOVE_BOXED(ptr, val, n_htop, &dummy_ref); } else { /* must be a cons cell */ ASSERT(ptr+1 < end); MOVE_CONS(ptr, val, n_htop, &dummy_ref); ptr += 2; } } return n_htop; } /* * Collect heap fragments and check that they point in the correct direction. */ static Eterm* collect_live_heap_frags(Process* p, ErlHeapFragment *live_hf_end, Eterm* n_hstart, Eterm* n_htop, Eterm* objv, int nobj) { ErlHeapFragment* qb; char* frag_begin; Uint frag_size; /* * Move the heap fragments to the new heap. Note that no GC is done on * the heap fragments. Any garbage will thus be moved as well and survive * until next GC. */ qb = MBUF(p); while (qb != live_hf_end) { ASSERT(!qb->off_heap.first); /* process fragments use the MSO(p) list */ frag_size = qb->used_size * sizeof(Eterm); if (frag_size != 0) { frag_begin = (char *) qb->mem; n_htop = move_one_area(n_htop, frag_begin, frag_size); } qb = qb->next; } return n_htop; } static Uint setup_rootset(Process *p, Eterm *objv, int nobj, Rootset *rootset) { Roots* roots; Uint n; n = 0; roots = rootset->roots = rootset->def; rootset->size = ALENGTH(rootset->def); roots[n].v = p->stop; roots[n].sz = STACK_START(p) - p->stop; ++n; if (p->dictionary != NULL) { roots[n].v = p->dictionary->data; roots[n].sz = p->dictionary->used; ++n; } if (nobj > 0) { roots[n].v = objv; roots[n].sz = nobj; ++n; } ASSERT((is_nil(p->seq_trace_token) || is_tuple(follow_moved(p->seq_trace_token, (Eterm) 0)) || is_atom(p->seq_trace_token))); if (is_not_immed(p->seq_trace_token)) { roots[n].v = &p->seq_trace_token; roots[n].sz = 1; n++; } #ifdef USE_VM_PROBES if (is_not_immed(p->dt_utag)) { roots[n].v = &p->dt_utag; roots[n].sz = 1; n++; } #endif ASSERT(is_nil(ERTS_TRACER_PROC(p)) || is_internal_pid(ERTS_TRACER_PROC(p)) || is_internal_port(ERTS_TRACER_PROC(p))); ASSERT(is_pid(follow_moved(p->group_leader, (Eterm) 0))); if (is_not_immed(p->group_leader)) { roots[n].v = &p->group_leader; roots[n].sz = 1; n++; } /* * The process may be garbage-collected while it is terminating. * (fvalue contains the EXIT reason and ftrace the saved stack trace.) */ if (is_not_immed(p->fvalue)) { roots[n].v = &p->fvalue; roots[n].sz = 1; n++; } if (is_not_immed(p->ftrace)) { roots[n].v = &p->ftrace; roots[n].sz = 1; n++; } /* * If a NIF has saved arguments, they need to be added */ if (ERTS_PROC_GET_NIF_TRAP_EXPORT(p)) { Eterm* argv; int argc; if (erts_setup_nif_gc(p, &argv, &argc)) { roots[n].v = argv; roots[n].sz = argc; n++; } } ASSERT(n <= rootset->size); switch (p->flags & (F_OFF_HEAP_MSGQ|F_OFF_HEAP_MSGQ_CHNG)) { case F_OFF_HEAP_MSGQ|F_OFF_HEAP_MSGQ_CHNG: (void) erts_move_messages_off_heap(p); case F_OFF_HEAP_MSGQ: break; case F_OFF_HEAP_MSGQ_CHNG: case 0: { /* * Off heap message queue disabled, i.e. we may * have references from the message queue to the * heap... */ ErtsMessage *mp; /* Ensure large enough rootset... */ if (n + p->msg.len > rootset->size) { Uint new_size = n + p->msg.len; ERTS_GC_ASSERT(roots == rootset->def); roots = erts_alloc(ERTS_ALC_T_ROOTSET, new_size*sizeof(Roots)); sys_memcpy(roots, rootset->def, n*sizeof(Roots)); rootset->size = new_size; } for (mp = p->msg.first; mp; mp = mp->next) { if (!mp->data.attached) { /* * Message may refer data on heap; * add it to rootset... */ roots[n].v = mp->m; roots[n].sz = ERL_MESSAGE_REF_ARRAY_SZ; n++; } } break; } } ASSERT(rootset->size >= n); rootset->roots = roots; rootset->num_roots = n; return n; } static void cleanup_rootset(Rootset* rootset) { if (rootset->roots != rootset->def) { erts_free(ERTS_ALC_T_ROOTSET, rootset->roots); } } static void grow_new_heap(Process *p, Uint new_sz, Eterm* objv, int nobj) { Eterm* new_heap; Uint heap_size = HEAP_TOP(p) - HEAP_START(p); Uint stack_size = p->hend - p->stop; Sint offs; ASSERT(HEAP_SIZE(p) < new_sz); new_heap = (Eterm *) ERTS_HEAP_REALLOC(ERTS_ALC_T_HEAP, (void *) HEAP_START(p), sizeof(Eterm)*(HEAP_SIZE(p)), sizeof(Eterm)*new_sz); if ((offs = new_heap - HEAP_START(p)) == 0) { /* No move. */ HEAP_END(p) = new_heap + new_sz; sys_memmove(p->hend - stack_size, p->stop, stack_size * sizeof(Eterm)); p->stop = p->hend - stack_size; } else { char* area = (char *) HEAP_START(p); Uint area_size = (char *) HEAP_TOP(p) - area; Eterm* prev_stop = p->stop; offset_heap(new_heap, heap_size, offs, area, area_size); HIGH_WATER(p) = new_heap + (HIGH_WATER(p) - HEAP_START(p)); HEAP_END(p) = new_heap + new_sz; prev_stop = new_heap + (p->stop - p->heap); p->stop = p->hend - stack_size; sys_memmove(p->stop, prev_stop, stack_size * sizeof(Eterm)); offset_rootset(p, offs, area, area_size, objv, nobj); HEAP_TOP(p) = new_heap + heap_size; HEAP_START(p) = new_heap; } #ifdef USE_VM_PROBES if (DTRACE_ENABLED(process_heap_grow)) { DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE); dtrace_proc_str(p, pidbuf); DTRACE3(process_heap_grow, pidbuf, HEAP_SIZE(p), new_sz); } #endif HEAP_SIZE(p) = new_sz; } static void shrink_new_heap(Process *p, Uint new_sz, Eterm *objv, int nobj) { Eterm* new_heap; Uint heap_size = HEAP_TOP(p) - HEAP_START(p); Sint offs; Uint stack_size = p->hend - p->stop; ASSERT(new_sz < p->heap_sz); sys_memmove(p->heap + new_sz - stack_size, p->stop, stack_size * sizeof(Eterm)); new_heap = (Eterm *) ERTS_HEAP_REALLOC(ERTS_ALC_T_HEAP, (void*)p->heap, sizeof(Eterm)*(HEAP_SIZE(p)), sizeof(Eterm)*new_sz); p->hend = new_heap + new_sz; p->stop = p->hend - stack_size; if ((offs = new_heap - HEAP_START(p)) != 0) { char* area = (char *) HEAP_START(p); Uint area_size = (char *) HEAP_TOP(p) - area; /* * Normally, we don't expect a shrunk heap to move, but you never * know on some strange embedded systems... Or when using purify. */ offset_heap(new_heap, heap_size, offs, area, area_size); HIGH_WATER(p) = new_heap + (HIGH_WATER(p) - HEAP_START(p)); offset_rootset(p, offs, area, area_size, objv, nobj); HEAP_TOP(p) = new_heap + heap_size; HEAP_START(p) = new_heap; } #ifdef USE_VM_PROBES if (DTRACE_ENABLED(process_heap_shrink)) { DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE); dtrace_proc_str(p, pidbuf); DTRACE3(process_heap_shrink, pidbuf, HEAP_SIZE(p), new_sz); } #endif HEAP_SIZE(p) = new_sz; } static Uint64 do_next_vheap_size(Uint64 vheap, Uint64 vheap_sz) { /* grow * * vheap_sz ====================== * * vheap 75% + grow * ---------------------- * * vheap 25 - 75% same * ---------------------- * * vheap ~ - 25% shrink * * ---------------------- */ if ((Uint64) vheap/3 > (Uint64) (vheap_sz/4)) { Uint64 new_vheap_sz = vheap_sz; while((Uint64) vheap/3 > (Uint64) (vheap_sz/4)) { /* the golden ratio = 1.618 */ new_vheap_sz = (Uint64) vheap_sz * 1.618; if (new_vheap_sz < vheap_sz ) { return vheap_sz; } vheap_sz = new_vheap_sz; } return vheap_sz; } if (vheap < (Uint64) (vheap_sz/4)) { return (vheap_sz >> 1); } return vheap_sz; } static Uint64 next_vheap_size(Process* p, Uint64 vheap, Uint64 vheap_sz) { Uint64 new_vheap_sz = do_next_vheap_size(vheap, vheap_sz); return new_vheap_sz < p->min_vheap_size ? p->min_vheap_size : new_vheap_sz; } struct shrink_cand_data { struct erl_off_heap_header* new_candidates; struct erl_off_heap_header* new_candidates_end; struct erl_off_heap_header* old_candidates; Uint no_of_candidates; Uint no_of_active; }; static ERTS_INLINE void link_live_proc_bin(struct shrink_cand_data *shrink, struct erl_off_heap_header*** prevppp, struct erl_off_heap_header** currpp, int new_heap) { ProcBin *pbp = (ProcBin*) *currpp; ASSERT(**prevppp == *currpp); *currpp = pbp->next; if (pbp->flags & (PB_ACTIVE_WRITER|PB_IS_WRITABLE)) { ASSERT(((pbp->flags & (PB_ACTIVE_WRITER|PB_IS_WRITABLE)) == (PB_ACTIVE_WRITER|PB_IS_WRITABLE)) || ((pbp->flags & (PB_ACTIVE_WRITER|PB_IS_WRITABLE)) == PB_IS_WRITABLE)); if (pbp->flags & PB_ACTIVE_WRITER) { shrink->no_of_active++; } else { /* inactive */ Uint unused = pbp->val->orig_size - pbp->size; /* Our allocators are 8 byte aligned, i.e., shrinking with less than 8 bytes will have no real effect */ if (unused >= 8) { /* A shrink candidate; save in candidate list */ **prevppp = pbp->next; if (new_heap) { if (!shrink->new_candidates) shrink->new_candidates_end = (struct erl_off_heap_header*)pbp; pbp->next = shrink->new_candidates; shrink->new_candidates = (struct erl_off_heap_header*)pbp; } else { pbp->next = shrink->old_candidates; shrink->old_candidates = (struct erl_off_heap_header*)pbp; } shrink->no_of_candidates++; return; } } } /* Not a shrink candidate; keep in original mso list */ *prevppp = &pbp->next; } static void sweep_off_heap(Process *p, int fullsweep) { struct shrink_cand_data shrink = {0}; struct erl_off_heap_header* ptr; struct erl_off_heap_header** prev; char* oheap = NULL; Uint oheap_sz = 0; Uint64 bin_vheap = 0; #ifdef DEBUG int seen_mature = 0; #endif if (fullsweep == 0) { oheap = (char *) OLD_HEAP(p); oheap_sz = (char *) OLD_HEND(p) - oheap; } BIN_OLD_VHEAP(p) = 0; prev = &MSO(p).first; ptr = MSO(p).first; /* Firts part of the list will reside on the (old) new-heap. * Keep if moved, otherwise deref. */ while (ptr) { if (IS_MOVED_BOXED(ptr->thing_word)) { ASSERT(!ErtsInArea(ptr, oheap, oheap_sz)); *prev = ptr = (struct erl_off_heap_header*) boxed_val(ptr->thing_word); ASSERT(!IS_MOVED_BOXED(ptr->thing_word)); if (ptr->thing_word == HEADER_PROC_BIN) { int to_new_heap = !ErtsInArea(ptr, oheap, oheap_sz); ASSERT(to_new_heap == !seen_mature || (!to_new_heap && (seen_mature=1))); if (to_new_heap) { bin_vheap += ptr->size / sizeof(Eterm); } else { BIN_OLD_VHEAP(p) += ptr->size / sizeof(Eterm); /* for binary gc (words)*/ } link_live_proc_bin(&shrink, &prev, &ptr, to_new_heap); } else { prev = &ptr->next; ptr = ptr->next; } } else if (!ErtsInArea(ptr, oheap, oheap_sz)) { /* garbage */ switch (thing_subtag(ptr->thing_word)) { case REFC_BINARY_SUBTAG: { Binary* bptr = ((ProcBin*)ptr)->val; if (erts_refc_dectest(&bptr->refc, 0) == 0) { erts_bin_free(bptr); } break; } case FUN_SUBTAG: { ErlFunEntry* fe = ((ErlFunThing*)ptr)->fe; if (erts_refc_dectest(&fe->refc, 0) == 0) { erts_erase_fun_entry(fe); } break; } default: ASSERT(is_external_header(ptr->thing_word)); erts_deref_node_entry(((ExternalThing*)ptr)->node); } *prev = ptr = ptr->next; } else break; /* and let old-heap loop continue */ } /* The rest of the list resides on old-heap, and we just did a * generational collection - keep objects in list. */ while (ptr) { ASSERT(ErtsInArea(ptr, oheap, oheap_sz)); ASSERT(!IS_MOVED_BOXED(ptr->thing_word)); if (ptr->thing_word == HEADER_PROC_BIN) { BIN_OLD_VHEAP(p) += ptr->size / sizeof(Eterm); /* for binary gc (words)*/ link_live_proc_bin(&shrink, &prev, &ptr, 0); } else { ASSERT(is_fun_header(ptr->thing_word) || is_external_header(ptr->thing_word)); prev = &ptr->next; ptr = ptr->next; } } if (fullsweep) { BIN_OLD_VHEAP_SZ(p) = next_vheap_size(p, BIN_OLD_VHEAP(p) + MSO(p).overhead, BIN_OLD_VHEAP_SZ(p)); } BIN_VHEAP_SZ(p) = next_vheap_size(p, bin_vheap, BIN_VHEAP_SZ(p)); MSO(p).overhead = bin_vheap; /* * If we got any shrink candidates, check them out. */ if (shrink.no_of_candidates) { ProcBin *candlist[] = { (ProcBin*)shrink.new_candidates, (ProcBin*)shrink.old_candidates }; Uint leave_unused = 0; int i; if (shrink.no_of_active == 0) { if (shrink.no_of_candidates <= ERTS_INACT_WR_PB_LEAVE_MUCH_LIMIT) leave_unused = ERTS_INACT_WR_PB_LEAVE_MUCH_PERCENTAGE; else if (shrink.no_of_candidates <= ERTS_INACT_WR_PB_LEAVE_LIMIT) leave_unused = ERTS_INACT_WR_PB_LEAVE_PERCENTAGE; } for (i = 0; i < sizeof(candlist)/sizeof(candlist[0]); i++) { ProcBin* pb; for (pb = candlist[i]; pb; pb = (ProcBin*)pb->next) { Uint new_size = pb->size; if (leave_unused) { new_size += (new_size * 100) / leave_unused; /* Our allocators are 8 byte aligned, i.e., shrinking with less than 8 bytes will have no real effect */ if (new_size + 8 >= pb->val->orig_size) continue; } pb->val = erts_bin_realloc(pb->val, new_size); pb->bytes = (byte *) pb->val->orig_bytes; } } /* * We now potentially have the mso list divided into three lists: * - shrink candidates on new heap (inactive writable with unused data) * - shrink candidates on old heap (inactive writable with unused data) * - other binaries (read only + active writable ...) + funs and externals * * Put them back together: new candidates -> other -> old candidates * This order will ensure that the list only refers from new * generation to old and never from old to new *which is important*. */ if (shrink.new_candidates) { if (prev == &MSO(p).first) /* empty other binaries list */ prev = &shrink.new_candidates_end->next; else shrink.new_candidates_end->next = MSO(p).first; MSO(p).first = shrink.new_candidates; } } *prev = shrink.old_candidates; } /* * Offset pointers into the heap (not stack). */ static void offset_heap(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size) { while (sz--) { Eterm val = *hp; switch (primary_tag(val)) { case TAG_PRIMARY_LIST: case TAG_PRIMARY_BOXED: if (ErtsInArea(ptr_val(val), area, area_size)) { *hp = offset_ptr(val, offs); } hp++; break; case TAG_PRIMARY_HEADER: { Uint tari; if (header_is_transparent(val)) { hp++; continue; } tari = thing_arityval(val); switch (thing_subtag(val)) { case REFC_BINARY_SUBTAG: case FUN_SUBTAG: case EXTERNAL_PID_SUBTAG: case EXTERNAL_PORT_SUBTAG: case EXTERNAL_REF_SUBTAG: { struct erl_off_heap_header* oh = (struct erl_off_heap_header*) hp; if (ErtsInArea(oh->next, area, area_size)) { Eterm** uptr = (Eterm **) (void *) &oh->next; *uptr += offs; /* Patch the mso chain */ } } break; case BIN_MATCHSTATE_SUBTAG: { ErlBinMatchState *ms = (ErlBinMatchState*) hp; ErlBinMatchBuffer *mb = &(ms->mb); if (ErtsInArea(ptr_val(mb->orig), area, area_size)) { mb->orig = offset_ptr(mb->orig, offs); mb->base = binary_bytes(mb->orig); } } break; } sz -= tari; hp += tari + 1; break; } default: hp++; continue; } } } /* * Offset pointers to heap from stack. */ static void offset_heap_ptr(Eterm* hp, Uint sz, Sint offs, char* area, Uint area_size) { while (sz--) { Eterm val = *hp; switch (primary_tag(val)) { case TAG_PRIMARY_LIST: case TAG_PRIMARY_BOXED: if (ErtsInArea(ptr_val(val), area, area_size)) { *hp = offset_ptr(val, offs); } hp++; break; default: hp++; break; } } } static void offset_off_heap(Process* p, Sint offs, char* area, Uint area_size) { if (MSO(p).first && ErtsInArea((Eterm *)MSO(p).first, area, area_size)) { Eterm** uptr = (Eterm**) (void *) &MSO(p).first; *uptr += offs; } } /* * Offset pointers in message queue. */ static void offset_mqueue(Process *p, Sint offs, char* area, Uint area_size) { ErtsMessage* mp = p->msg.first; while (mp != NULL) { Eterm mesg = ERL_MESSAGE_TERM(mp); if (is_value(mesg)) { switch (primary_tag(mesg)) { case TAG_PRIMARY_LIST: case TAG_PRIMARY_BOXED: if (ErtsInArea(ptr_val(mesg), area, area_size)) { ERL_MESSAGE_TERM(mp) = offset_ptr(mesg, offs); } break; } } mesg = ERL_MESSAGE_TOKEN(mp); if (is_boxed(mesg) && ErtsInArea(ptr_val(mesg), area, area_size)) { ERL_MESSAGE_TOKEN(mp) = offset_ptr(mesg, offs); } #ifdef USE_VM_PROBES mesg = ERL_MESSAGE_DT_UTAG(mp); if (is_boxed(mesg) && ErtsInArea(ptr_val(mesg), area, area_size)) { ERL_MESSAGE_DT_UTAG(mp) = offset_ptr(mesg, offs); } #endif ASSERT((is_nil(ERL_MESSAGE_TOKEN(mp)) || is_tuple(ERL_MESSAGE_TOKEN(mp)) || is_atom(ERL_MESSAGE_TOKEN(mp)))); mp = mp->next; } } static void ERTS_INLINE offset_one_rootset(Process *p, Sint offs, char* area, Uint area_size, Eterm* objv, int nobj) { if (p->dictionary) { offset_heap(p->dictionary->data, p->dictionary->used, offs, area, area_size); } offset_heap_ptr(&p->fvalue, 1, offs, area, area_size); offset_heap_ptr(&p->ftrace, 1, offs, area, area_size); offset_heap_ptr(&p->seq_trace_token, 1, offs, area, area_size); #ifdef USE_VM_PROBES offset_heap_ptr(&p->dt_utag, 1, offs, area, area_size); #endif offset_heap_ptr(&p->group_leader, 1, offs, area, area_size); offset_mqueue(p, offs, area, area_size); offset_heap_ptr(p->stop, (STACK_START(p) - p->stop), offs, area, area_size); offset_nstack(p, offs, area, area_size); if (nobj > 0) { offset_heap_ptr(objv, nobj, offs, area, area_size); } offset_off_heap(p, offs, area, area_size); } static void offset_rootset(Process *p, Sint offs, char* area, Uint area_size, Eterm* objv, int nobj) { offset_one_rootset(p, offs, area, area_size, objv, nobj); } static void init_gc_info(ErtsGCInfo *gcip) { gcip->reclaimed = 0; gcip->garbage_cols = 0; } static void reply_gc_info(void *vgcirp) { Uint64 reclaimed = 0, garbage_cols = 0; ErtsSchedulerData *esdp = erts_get_scheduler_data(); ErtsGCInfoReq *gcirp = (ErtsGCInfoReq *) vgcirp; ErtsProcLocks rp_locks = (gcirp->req_sched == esdp->no ? ERTS_PROC_LOCK_MAIN : 0); Process *rp = gcirp->proc; Eterm ref_copy = NIL, msg; Eterm *hp = NULL; Eterm **hpp; Uint sz, *szp; ErlOffHeap *ohp = NULL; ErtsMessage *mp = NULL; ASSERT(esdp); reclaimed = esdp->gc_info.reclaimed; garbage_cols = esdp->gc_info.garbage_cols; sz = 0; hpp = NULL; szp = &sz; while (1) { if (hpp) ref_copy = STORE_NC(hpp, ohp, gcirp->ref); else *szp += REF_THING_SIZE; msg = erts_bld_tuple(hpp, szp, 3, make_small(esdp->no), erts_bld_uint64(hpp, szp, garbage_cols), erts_bld_uint64(hpp, szp, reclaimed)); msg = erts_bld_tuple(hpp, szp, 2, ref_copy, msg); if (hpp) break; mp = erts_alloc_message_heap(rp, &rp_locks, sz, &hp, &ohp); szp = NULL; hpp = &hp; } erts_queue_message(rp, &rp_locks, mp, msg, NIL); if (gcirp->req_sched == esdp->no) rp_locks &= ~ERTS_PROC_LOCK_MAIN; if (rp_locks) erts_smp_proc_unlock(rp, rp_locks); erts_proc_dec_refc(rp); if (erts_smp_atomic32_dec_read_nob(&gcirp->refc) == 0) gcireq_free(vgcirp); } Eterm erts_gc_info_request(Process *c_p) { ErtsSchedulerData *esdp = ERTS_PROC_GET_SCHDATA(c_p); Eterm ref; ErtsGCInfoReq *gcirp; Eterm *hp; gcirp = gcireq_alloc(); ref = erts_make_ref(c_p); hp = &gcirp->ref_heap[0]; gcirp->proc = c_p; gcirp->ref = STORE_NC(&hp, NULL, ref); gcirp->req_sched = esdp->no; erts_smp_atomic32_init_nob(&gcirp->refc, (erts_aint32_t) erts_no_schedulers); erts_proc_add_refc(c_p, (Sint) erts_no_schedulers); #ifdef ERTS_SMP if (erts_no_schedulers > 1) erts_schedule_multi_misc_aux_work(1, erts_no_schedulers, reply_gc_info, (void *) gcirp); #endif reply_gc_info((void *) gcirp); return ref; } #if defined(DEBUG) || defined(ERTS_OFFHEAP_DEBUG) static int within2(Eterm *ptr, Process *p, Eterm *real_htop) { ErlHeapFragment* bp; ErtsMessage* mp; Eterm *htop, *heap; if (p->abandoned_heap) ERTS_GET_ORIG_HEAP(p, heap, htop); else { heap = p->heap; htop = real_htop ? real_htop : HEAP_TOP(p); } if (OLD_HEAP(p) && (OLD_HEAP(p) <= ptr && ptr < OLD_HEND(p))) { return 1; } if (heap <= ptr && ptr < htop) { return 1; } mp = p->msg_frag; bp = p->mbuf; if (bp) goto search_heap_frags; while (mp) { if (mp->data.attached == ERTS_MSG_COMBINED_HFRAG) bp = &mp->hfrag; else bp = mp->data.heap_frag; mp = mp->next; search_heap_frags: while (bp) { if (bp->mem <= ptr && ptr < bp->mem + bp->used_size) { return 1; } bp = bp->next; } } return 0; } int within(Eterm *ptr, Process *p) { return within2(ptr, p, NULL); } #endif #ifdef ERTS_OFFHEAP_DEBUG #define ERTS_CHK_OFFHEAP_ASSERT(EXP) \ do { \ if (!(EXP)) \ erl_exit(ERTS_ABORT_EXIT, \ "%s:%d: Assertion failed: %s\n", \ __FILE__, __LINE__, #EXP); \ } while (0) #ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_LIST # define ERTS_OFFHEAP_VISITED_BIT ((Eterm) 1 << 31) #endif void erts_check_off_heap2(Process *p, Eterm *htop) { Eterm *oheap = (Eterm *) OLD_HEAP(p); Eterm *ohtop = (Eterm *) OLD_HTOP(p); int old; union erl_off_heap_ptr u; old = 0; for (u.hdr = MSO(p).first; u.hdr; u.hdr = u.hdr->next) { erts_aint_t refc; switch (thing_subtag(u.hdr->thing_word)) { case REFC_BINARY_SUBTAG: refc = erts_refc_read(&u.pb->val->refc, 1); break; case FUN_SUBTAG: refc = erts_refc_read(&u.fun->fe->refc, 1); break; case EXTERNAL_PID_SUBTAG: case EXTERNAL_PORT_SUBTAG: case EXTERNAL_REF_SUBTAG: refc = erts_refc_read(&u.ext->node->refc, 1); break; default: ASSERT(!"erts_check_off_heap2: Invalid thing_word"); } ERTS_CHK_OFFHEAP_ASSERT(refc >= 1); #ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_LIST ERTS_CHK_OFFHEAP_ASSERT(!(u.hdr->thing_word & ERTS_OFFHEAP_VISITED_BIT)); u.hdr->thing_word |= ERTS_OFFHEAP_VISITED_BIT; #endif if (old) { ERTS_CHK_OFFHEAP_ASSERT(oheap <= u.ep && u.ep < ohtop); } else if (oheap <= u.ep && u.ep < ohtop) old = 1; else { ERTS_CHK_OFFHEAP_ASSERT(within2(u.ep, p, htop)); } } #ifdef ERTS_OFFHEAP_DEBUG_CHK_CIRCULAR_LIST for (u.hdr = MSO(p).first; u.hdr; u.hdr = u.hdr->next) u.hdr->thing_word &= ~ERTS_OFFHEAP_VISITED_BIT; #endif } void erts_check_off_heap(Process *p) { erts_check_off_heap2(p, NULL); } #endif