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50b0d148a6
Fix a crash at Python exit when a deallocator function removes the
last strong reference to a heap type.
Don't read type memory after calling basedealloc() since
basedealloc() can deallocate the type and free its memory.
_PyMem_IsPtrFreed() argument is now constant.
(cherry picked from commit 615069eb08)
Co-authored-by: Victor Stinner <vstinner@python.org>
Co-authored-by: Victor Stinner <vstinner@python.org>
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
#ifndef Py_INTERNAL_PYMEM_H
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#define Py_INTERNAL_PYMEM_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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#ifndef Py_BUILD_CORE
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# error "this header requires Py_BUILD_CORE define"
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#endif
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#include "pymem.h" // PyMemAllocatorName
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/* Set the memory allocator of the specified domain to the default.
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Save the old allocator into *old_alloc if it's non-NULL.
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Return on success, or return -1 if the domain is unknown. */
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PyAPI_FUNC(int) _PyMem_SetDefaultAllocator(
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PyMemAllocatorDomain domain,
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PyMemAllocatorEx *old_alloc);
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/* Special bytes broadcast into debug memory blocks at appropriate times.
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Strings of these are unlikely to be valid addresses, floats, ints or
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7-bit ASCII.
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- PYMEM_CLEANBYTE: clean (newly allocated) memory
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- PYMEM_DEADBYTE dead (newly freed) memory
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- PYMEM_FORBIDDENBYTE: untouchable bytes at each end of a block
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Byte patterns 0xCB, 0xDB and 0xFB have been replaced with 0xCD, 0xDD and
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0xFD to use the same values than Windows CRT debug malloc() and free().
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If modified, _PyMem_IsPtrFreed() should be updated as well. */
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#define PYMEM_CLEANBYTE 0xCD
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#define PYMEM_DEADBYTE 0xDD
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#define PYMEM_FORBIDDENBYTE 0xFD
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/* Heuristic checking if a pointer value is newly allocated
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(uninitialized), newly freed or NULL (is equal to zero).
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The pointer is not dereferenced, only the pointer value is checked.
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The heuristic relies on the debug hooks on Python memory allocators which
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fills newly allocated memory with CLEANBYTE (0xCD) and newly freed memory
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with DEADBYTE (0xDD). Detect also "untouchable bytes" marked
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with FORBIDDENBYTE (0xFD). */
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static inline int _PyMem_IsPtrFreed(const void *ptr)
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{
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uintptr_t value = (uintptr_t)ptr;
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#if SIZEOF_VOID_P == 8
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return (value == 0
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|| value == (uintptr_t)0xCDCDCDCDCDCDCDCD
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|| value == (uintptr_t)0xDDDDDDDDDDDDDDDD
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|| value == (uintptr_t)0xFDFDFDFDFDFDFDFD);
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#elif SIZEOF_VOID_P == 4
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return (value == 0
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|| value == (uintptr_t)0xCDCDCDCD
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|| value == (uintptr_t)0xDDDDDDDD
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|| value == (uintptr_t)0xFDFDFDFD);
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#else
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# error "unknown pointer size"
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#endif
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}
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PyAPI_FUNC(int) _PyMem_GetAllocatorName(
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const char *name,
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PyMemAllocatorName *allocator);
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/* Configure the Python memory allocators.
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Pass PYMEM_ALLOCATOR_DEFAULT to use default allocators.
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PYMEM_ALLOCATOR_NOT_SET does nothing. */
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PyAPI_FUNC(int) _PyMem_SetupAllocators(PyMemAllocatorName allocator);
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struct _PyTraceMalloc_Config {
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/* Module initialized?
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Variable protected by the GIL */
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enum {
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TRACEMALLOC_NOT_INITIALIZED,
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TRACEMALLOC_INITIALIZED,
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TRACEMALLOC_FINALIZED
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} initialized;
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/* Is tracemalloc tracing memory allocations?
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Variable protected by the GIL */
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int tracing;
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/* limit of the number of frames in a traceback, 1 by default.
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Variable protected by the GIL. */
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int max_nframe;
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};
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#define _PyTraceMalloc_Config_INIT \
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{.initialized = TRACEMALLOC_NOT_INITIALIZED, \
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.tracing = 0, \
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.max_nframe = 1}
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PyAPI_DATA(struct _PyTraceMalloc_Config) _Py_tracemalloc_config;
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#ifdef __cplusplus
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}
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#endif
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#endif /* !Py_INTERNAL_PYMEM_H */
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