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