Issue #26588: Fix _tracemalloc start/stop: don't play with the reentrant flag.
set_reentrant(1) fails with an assertion error if tracemalloc_init() is called
first in a thread A and tracemalloc_start() is called second in a thread B. The
tracemalloc is imported in a thread A. Importing the module calls
tracemalloc_init(). tracemalloc.start() is called in a thread B.
regression was introduced recently with the introduction of the new "calloc"
functions (PyMem_RawCalloc, PyMem_Calloc, PyObject_Calloc).
Add also a unit test to check for the non-regression.
PyObject_Calloc(), _PyObject_GC_Calloc(). bytes(int) and bytearray(int) are now
using ``calloc()`` instead of ``malloc()`` for large objects which is faster
and use less memory (until the bytearray buffer is filled with data).
platforms. Bug seen on 64-bit Linux when using "make profile-opt".
Only align the "frame_t" structure on 32-bit when Visual Studio is used. Before
the alignment to 32-bit was applied to the whole file any compiler supporting
"#pragma pack(4)" which includes GCC.
In Python 3.3, PyThread_set_key_value() did nothing if the key already exists
(if the current value is a non-NULL pointer).
When _PyGILState_NoteThreadState() is called twice on the same thread with a
different Python thread state, it still keeps the old Python thread state to
keep the old behaviour. Replacing the Python thread state with the new state
introduces new bugs: see issues #10915 and #15751.
the function did nothing if the key already exists (if the current value is a
non-NULL pointer).
_testcapi.run_in_subinterp() now correctly sets the new Python thread state of
the current thread when a subinterpreter is created.
between tracemalloc_remove_trace() and tracemalloc_add_trace() to reduce the
risk of race condition.
tracemalloc_add_trace() cannot fail anymore in tracemalloc_realloc() when
tracemalloc_realloc() resizes a memory block.
PyGILState_Ensure()/PyGILState_Release() calls to the raw wrappers to simplify
the code.
Rename also tracemalloc_log_alloc/log_free() to
tracemalloc_add_trace/remove_trace().
The limit is now 178,956,969 on 64 bit (it is greater on 32 bit because
structures are smaller).
Use int instead of Py_ssize_t to store the number of frames to have smaller
traceback_t objects.