OVMS3/OVMS.V3/components/duktape/src-separate/duk_heap_memory.c

413 lines
11 KiB
C
Raw Normal View History

/*
* Memory allocation handling.
*/
#include "duk_internal.h"
/*
* Allocate memory with garbage collection.
*/
/* Slow path: voluntary GC triggered, first alloc attempt failed, or zero size. */
DUK_LOCAL DUK_NOINLINE_PERF DUK_COLD void *duk__heap_mem_alloc_slowpath(duk_heap *heap, duk_size_t size) {
void *res;
duk_small_int_t i;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->alloc_func != NULL);
DUK_ASSERT_DISABLE(size >= 0);
if (size == 0) {
DUK_D(DUK_DPRINT("zero size alloc in slow path, return NULL"));
return NULL;
}
DUK_D(DUK_DPRINT("first alloc attempt failed or voluntary GC limit reached, attempt to gc and retry"));
#if 0
/*
* If GC is already running there is no point in attempting a GC
* because it will be skipped. This could be checked for explicitly,
* but it isn't actually needed: the loop below will eventually
* fail resulting in a NULL.
*/
if (heap->ms_prevent_count != 0) {
DUK_D(DUK_DPRINT("duk_heap_mem_alloc() failed, gc in progress (gc skipped), alloc size %ld", (long) size));
return NULL;
}
#endif
/*
* Retry with several GC attempts. Initial attempts are made without
* emergency mode; later attempts use emergency mode which minimizes
* memory allocations forcibly.
*/
for (i = 0; i < DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_LIMIT; i++) {
duk_small_uint_t flags;
flags = 0;
if (i >= DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_EMERGENCY_LIMIT - 1) {
flags |= DUK_MS_FLAG_EMERGENCY;
}
duk_heap_mark_and_sweep(heap, flags);
DUK_ASSERT(size > 0);
res = heap->alloc_func(heap->heap_udata, size);
if (res != NULL) {
DUK_D(DUK_DPRINT("duk_heap_mem_alloc() succeeded after gc (pass %ld), alloc size %ld",
(long) (i + 1), (long) size));
return res;
}
}
DUK_D(DUK_DPRINT("duk_heap_mem_alloc() failed even after gc, alloc size %ld", (long) size));
return NULL;
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_alloc(duk_heap *heap, duk_size_t size) {
void *res;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->alloc_func != NULL);
DUK_ASSERT_DISABLE(size >= 0);
#if defined(DUK_USE_VOLUNTARY_GC)
/* Voluntary periodic GC (if enabled). */
if (DUK_UNLIKELY(--(heap)->ms_trigger_counter < 0)) {
goto slowpath;
}
#endif
#if defined(DUK_USE_GC_TORTURE)
/* Simulate alloc failure on every alloc, except when mark-and-sweep
* is running.
*/
if (heap->ms_prevent_count == 0) {
DUK_DDD(DUK_DDDPRINT("gc torture enabled, pretend that first alloc attempt fails"));
res = NULL;
DUK_UNREF(res);
goto slowpath;
}
#endif
/* Zero-size allocation should happen very rarely (if at all), so
* don't check zero size on NULL; handle it in the slow path
* instead. This reduces size of inlined code.
*/
res = heap->alloc_func(heap->heap_udata, size);
if (DUK_LIKELY(res != NULL)) {
return res;
}
slowpath:
if (size == 0) {
DUK_D(DUK_DPRINT("first alloc attempt returned NULL for zero size alloc, use slow path to deal with it"));
} else {
DUK_D(DUK_DPRINT("first alloc attempt failed, attempt to gc and retry"));
}
return duk__heap_mem_alloc_slowpath(heap, size);
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_alloc_zeroed(duk_heap *heap, duk_size_t size) {
void *res;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->alloc_func != NULL);
DUK_ASSERT_DISABLE(size >= 0);
res = DUK_ALLOC(heap, size);
if (DUK_LIKELY(res != NULL)) {
duk_memzero(res, size);
}
return res;
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_alloc_checked(duk_hthread *thr, duk_size_t size) {
void *res;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(thr->heap->alloc_func != NULL);
res = duk_heap_mem_alloc(thr->heap, size);
if (DUK_LIKELY(res != NULL)) {
return res;
} else if (size == 0) {
DUK_ASSERT(res == NULL);
return res;
}
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return NULL;);
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_alloc_checked_zeroed(duk_hthread *thr, duk_size_t size) {
void *res;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT(thr->heap->alloc_func != NULL);
res = duk_heap_mem_alloc(thr->heap, size);
if (DUK_LIKELY(res != NULL)) {
duk_memzero(res, size);
return res;
} else if (size == 0) {
DUK_ASSERT(res == NULL);
return res;
}
DUK_ERROR_ALLOC_FAILED(thr);
DUK_WO_NORETURN(return NULL;);
}
/*
* Reallocate memory with garbage collection.
*/
/* Slow path: voluntary GC triggered, first realloc attempt failed, or zero size. */
DUK_LOCAL DUK_NOINLINE_PERF DUK_COLD void *duk__heap_mem_realloc_slowpath(duk_heap *heap, void *ptr, duk_size_t newsize) {
void *res;
duk_small_int_t i;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->realloc_func != NULL);
/* ptr may be NULL */
DUK_ASSERT_DISABLE(newsize >= 0);
/* Newsize was 0 and realloc() returned NULL, this has the semantics
* of free(oldptr), i.e. memory was successfully freed.
*/
if (newsize == 0) {
DUK_D(DUK_DPRINT("zero size realloc in slow path, return NULL"));
return NULL;
}
DUK_D(DUK_DPRINT("first realloc attempt failed, attempt to gc and retry"));
#if 0
/*
* Avoid a GC if GC is already running. See duk_heap_mem_alloc().
*/
if (heap->ms_prevent_count != 0) {
DUK_D(DUK_DPRINT("duk_heap_mem_realloc() failed, gc in progress (gc skipped), alloc size %ld", (long) newsize));
return NULL;
}
#endif
/*
* Retry with several GC attempts. Initial attempts are made without
* emergency mode; later attempts use emergency mode which minimizes
* memory allocations forcibly.
*/
for (i = 0; i < DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_LIMIT; i++) {
duk_small_uint_t flags;
flags = 0;
if (i >= DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_EMERGENCY_LIMIT - 1) {
flags |= DUK_MS_FLAG_EMERGENCY;
}
duk_heap_mark_and_sweep(heap, flags);
DUK_ASSERT(newsize > 0);
res = heap->realloc_func(heap->heap_udata, ptr, newsize);
if (res || newsize == 0) {
DUK_D(DUK_DPRINT("duk_heap_mem_realloc() succeeded after gc (pass %ld), alloc size %ld",
(long) (i + 1), (long) newsize));
return res;
}
}
DUK_D(DUK_DPRINT("duk_heap_mem_realloc() failed even after gc, alloc size %ld", (long) newsize));
return NULL;
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_realloc(duk_heap *heap, void *ptr, duk_size_t newsize) {
void *res;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->realloc_func != NULL);
/* ptr may be NULL */
DUK_ASSERT_DISABLE(newsize >= 0);
#if defined(DUK_USE_VOLUNTARY_GC)
/* Voluntary periodic GC (if enabled). */
if (DUK_UNLIKELY(--(heap)->ms_trigger_counter < 0)) {
goto slowpath;
}
#endif
#if defined(DUK_USE_GC_TORTURE)
/* Simulate alloc failure on every realloc, except when mark-and-sweep
* is running.
*/
if (heap->ms_prevent_count == 0) {
DUK_DDD(DUK_DDDPRINT("gc torture enabled, pretend that first realloc attempt fails"));
res = NULL;
DUK_UNREF(res);
goto slowpath;
}
#endif
res = heap->realloc_func(heap->heap_udata, ptr, newsize);
if (DUK_LIKELY(res != NULL)) {
return res;
}
slowpath:
if (newsize == 0) {
DUK_D(DUK_DPRINT("first realloc attempt returned NULL for zero size realloc, use slow path to deal with it"));
} else {
DUK_D(DUK_DPRINT("first realloc attempt failed, attempt to gc and retry"));
}
return duk__heap_mem_realloc_slowpath(heap, ptr, newsize);
}
/*
* Reallocate memory with garbage collection, using a callback to provide
* the current allocated pointer. This variant is used when a mark-and-sweep
* (e.g. finalizers) might change the original pointer.
*/
/* Slow path: voluntary GC triggered, first realloc attempt failed, or zero size. */
DUK_LOCAL DUK_NOINLINE_PERF DUK_COLD void *duk__heap_mem_realloc_indirect_slowpath(duk_heap *heap, duk_mem_getptr cb, void *ud, duk_size_t newsize) {
void *res;
duk_small_int_t i;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->realloc_func != NULL);
DUK_ASSERT_DISABLE(newsize >= 0);
if (newsize == 0) {
DUK_D(DUK_DPRINT("zero size indirect realloc in slow path, return NULL"));
return NULL;
}
DUK_D(DUK_DPRINT("first indirect realloc attempt failed, attempt to gc and retry"));
#if 0
/*
* Avoid a GC if GC is already running. See duk_heap_mem_alloc().
*/
if (heap->ms_prevent_count != 0) {
DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() failed, gc in progress (gc skipped), alloc size %ld", (long) newsize));
return NULL;
}
#endif
/*
* Retry with several GC attempts. Initial attempts are made without
* emergency mode; later attempts use emergency mode which minimizes
* memory allocations forcibly.
*/
for (i = 0; i < DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_LIMIT; i++) {
duk_small_uint_t flags;
#if defined(DUK_USE_DEBUG)
void *ptr_pre;
void *ptr_post;
#endif
#if defined(DUK_USE_DEBUG)
ptr_pre = cb(heap, ud);
#endif
flags = 0;
if (i >= DUK_HEAP_ALLOC_FAIL_MARKANDSWEEP_EMERGENCY_LIMIT - 1) {
flags |= DUK_MS_FLAG_EMERGENCY;
}
duk_heap_mark_and_sweep(heap, flags);
#if defined(DUK_USE_DEBUG)
ptr_post = cb(heap, ud);
if (ptr_pre != ptr_post) {
DUK_DD(DUK_DDPRINT("realloc base pointer changed by mark-and-sweep: %p -> %p",
(void *) ptr_pre, (void *) ptr_post));
}
#endif
/* Note: key issue here is to re-lookup the base pointer on every attempt.
* The pointer being reallocated may change after every mark-and-sweep.
*/
DUK_ASSERT(newsize > 0);
res = heap->realloc_func(heap->heap_udata, cb(heap, ud), newsize);
if (res || newsize == 0) {
DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() succeeded after gc (pass %ld), alloc size %ld",
(long) (i + 1), (long) newsize));
return res;
}
}
DUK_D(DUK_DPRINT("duk_heap_mem_realloc_indirect() failed even after gc, alloc size %ld", (long) newsize));
return NULL;
}
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void *duk_heap_mem_realloc_indirect(duk_heap *heap, duk_mem_getptr cb, void *ud, duk_size_t newsize) {
void *res;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->realloc_func != NULL);
DUK_ASSERT_DISABLE(newsize >= 0);
#if defined(DUK_USE_VOLUNTARY_GC)
/* Voluntary periodic GC (if enabled). */
if (DUK_UNLIKELY(--(heap)->ms_trigger_counter < 0)) {
goto slowpath;
}
#endif
#if defined(DUK_USE_GC_TORTURE)
/* Simulate alloc failure on every realloc, except when mark-and-sweep
* is running.
*/
if (heap->ms_prevent_count == 0) {
DUK_DDD(DUK_DDDPRINT("gc torture enabled, pretend that first indirect realloc attempt fails"));
res = NULL;
DUK_UNREF(res);
goto slowpath;
}
#endif
res = heap->realloc_func(heap->heap_udata, cb(heap, ud), newsize);
if (DUK_LIKELY(res != NULL)) {
return res;
}
slowpath:
if (newsize == 0) {
DUK_D(DUK_DPRINT("first indirect realloc attempt returned NULL for zero size realloc, use slow path to deal with it"));
} else {
DUK_D(DUK_DPRINT("first indirect realloc attempt failed, attempt to gc and retry"));
}
return duk__heap_mem_realloc_indirect_slowpath(heap, cb, ud, newsize);
}
/*
* Free memory
*/
DUK_INTERNAL DUK_INLINE_PERF DUK_HOT void duk_heap_mem_free(duk_heap *heap, void *ptr) {
DUK_ASSERT(heap != NULL);
DUK_ASSERT(heap->free_func != NULL);
/* ptr may be NULL */
/* Must behave like a no-op with NULL and any pointer returned from
* malloc/realloc with zero size.
*/
heap->free_func(heap->heap_udata, ptr);
/* Never perform a GC (even voluntary) in a memory free, otherwise
* all call sites doing frees would need to deal with the side effects.
* No need to update voluntary GC counter either.
*/
}