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object_stack.c
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66 lines (58 loc) · 1.63 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 *);
_PyObjectStackChunk *
_PyObjectStackChunk_New(void)
{
_PyObjectStackChunk *buf = _Py_FREELIST_POP_MEM(object_stack_chunks);
if (buf == NULL) {
// 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);
_Py_FREELIST_FREE(object_stack_chunks, buf, PyMem_RawFree);
}
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;
}