Global freelist by methane · Pull Request #29089 · python/cpython

Expand Up @@ -29,6 +29,7 @@ static void _PyObject_DebugDumpAddress(const void *p); static void _PyMem_DebugCheckAddress(const char *func, char api_id, const void *p);
static void _PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain); static void _PyFreelist_DebugMallocStats(FILE *out);
#if defined(__has_feature) /* Clang */ # if __has_feature(address_sanitizer) /* is ASAN enabled? */ Expand Down Expand Up @@ -3079,7 +3080,102 @@ _PyObject_DebugMallocStats(FILE *out) #endif #endif
_PyFreelist_DebugMallocStats(out); return 1; }
#endif /* #ifdef WITH_PYMALLOC */
// Freelist support. See Include/cpython/objimpl.h
#define _PY_FREELIST_MAXSIZECLASS (256/_PY_FREELIST_ALIGNMENT) #define _PY_FREELIST_MAXLENGTH (1000) #define _PY_FREELIST_STAT 1
typedef struct { void *ptr; size_t nfree; #if _PY_FREELIST_STAT size_t reused; size_t allocated; #endif } _Py_freelist_slot;
static _Py_freelist_slot _Py_global_freelist[_PY_FREELIST_MAXSIZECLASS];
void* _PyFreelist_Malloc(size_t size) { assert(size > 0); size_t sc = (size-1) / _PY_FREELIST_ALIGNMENT; if (sc < _PY_FREELIST_MAXSIZECLASS) { _Py_freelist_slot *slot = &_Py_global_freelist[sc]; if (slot->nfree > 0) { void *ret = slot->ptr; slot->ptr = *((void**)ret); slot->nfree--; #if _PY_FREELIST_STAT slot->reused++; #endif return ret; } #if _PY_FREELIST_STAT slot->allocated++; #endif size = (sc+1) * _PY_FREELIST_ALIGNMENT; } return PyObject_Malloc(size); }
void _PyFreelist_Free(void *ptr, size_t size) { assert(size > 0); size_t sc = (size-1) / _PY_FREELIST_ALIGNMENT; if (sc < _PY_FREELIST_MAXSIZECLASS) { _Py_freelist_slot *slot = &_Py_global_freelist[sc]; if (slot->nfree < _PY_FREELIST_MAXLENGTH) { *((void**)ptr) = slot->ptr; slot->ptr = ptr; slot->nfree++; return; } } PyObject_Free(ptr); }
static void _PyFreelist_DebugMallocStats(FILE *out) { char buf[128];
#if _PY_FREELIST_STAT fputs("\nFreelist stats:\n\n" "size num free total bytes reused alloc\n" "---- -------- ----------- -------- --------\n", out);
for (int i = 0; i < _PY_FREELIST_MAXSIZECLASS; i++) { int n = (int)_Py_global_freelist[i].nfree; int s = (i + 1) * _PY_FREELIST_ALIGNMENT; PyOS_snprintf(buf, sizeof(buf), "%4d %8d %11d %8ld %8ld\n", s, n, s * n, _Py_global_freelist[i].reused, _Py_global_freelist[i].allocated); fputs(buf, out); } #else fputs("\nFreelist stats:\n\n" "size num free total bytes\n" "---- -------- -----------\n", out);
for (int i = 0; i < _PY_FREELIST_MAXSIZECLASS; i++) { int n = (int)_Py_global_freelist[i].nfree; int s = (i + 1) * _PY_FREELIST_ALIGNMENT; PyOS_snprintf(buf, sizeof(buf), "%4d %8d %11d\n", s, n, s * n); fputs(buf, out); } #endif }