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Copy pathobject_stack.c
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108 lines (97 loc) · 2.92 KB
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// Stack of Python objects
#include "Python.h"
#include "pycore_freelist.h"
#include "pycore_pystate.h"
#include "pycore_object_stack.h"
extern _PyObjectStackChunk *_PyObjectStackChunk_New(void);
extern void _PyObjectStackChunk_Free(_PyObjectStackChunk *);
static struct _Py_object_stack_freelist *
get_object_stack_freelist(void)
{
struct _Py_object_freelists *freelists = _Py_object_freelists_GET();
return &freelists->object_stacks;
}
_PyObjectStackChunk *
_PyObjectStackChunk_New(void)
{
_PyObjectStackChunk *buf;
struct _Py_object_stack_freelist *obj_stack_freelist = get_object_stack_freelist();
if (obj_stack_freelist->numfree > 0) {
buf = obj_stack_freelist->items;
obj_stack_freelist->items = buf->prev;
obj_stack_freelist->numfree--;
}
else {
// NOTE: we use PyMem_RawMalloc() here because this is used by the GC
// during mimalloc heap traversal. In that context, it is not safe to
// allocate mimalloc memory, such as via PyMem_Malloc().
buf = PyMem_RawMalloc(sizeof(_PyObjectStackChunk));
if (buf == NULL) {
return NULL;
}
}
buf->prev = NULL;
buf->n = 0;
return buf;
}
void
_PyObjectStackChunk_Free(_PyObjectStackChunk *buf)
{
assert(buf->n == 0);
struct _Py_object_stack_freelist *obj_stack_freelist = get_object_stack_freelist();
if (obj_stack_freelist->numfree >= 0 &&
obj_stack_freelist->numfree < _PyObjectStackChunk_MAXFREELIST)
{
buf->prev = obj_stack_freelist->items;
obj_stack_freelist->items = buf;
obj_stack_freelist->numfree++;
}
else {
PyMem_RawFree(buf);
}
}
void
_PyObjectStack_Clear(_PyObjectStack *queue)
{
while (queue->head != NULL) {
_PyObjectStackChunk *buf = queue->head;
buf->n = 0;
queue->head = buf->prev;
_PyObjectStackChunk_Free(buf);
}
}
void
_PyObjectStack_Merge(_PyObjectStack *dst, _PyObjectStack *src)
{
if (src->head == NULL) {
return;
}
if (dst->head != NULL) {
// First, append dst to the bottom of src
_PyObjectStackChunk *last = src->head;
while (last->prev != NULL) {
last = last->prev;
}
last->prev = dst->head;
}
// Now that src has all the chunks, set dst to src
dst->head = src->head;
src->head = NULL;
}
void
_PyObjectStackChunk_ClearFreeList(struct _Py_object_freelists *freelists, int is_finalization)
{
if (!is_finalization) {
// Ignore requests to clear the free list during GC. We use object
// stacks during GC, so emptying the free-list is counterproductive.
return;
}
struct _Py_object_stack_freelist *freelist = &freelists->object_stacks;
while (freelist->numfree > 0) {
_PyObjectStackChunk *buf = freelist->items;
freelist->items = buf->prev;
freelist->numfree--;
PyMem_RawFree(buf);
}
freelist->numfree = -1;
}