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gh-88750: Remove the PYTHONTHREADDEBUG env var support. #92509

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Merged
merged 2 commits into from
May 9, 2022
Merged

gh-88750: Remove the PYTHONTHREADDEBUG env var support. #92509

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26d5d04
gh-88750: Remove the PYTHONTHREADDEBUG env var support.
gpshead May 8, 2022
eca2d05
Remove no-op dprintf() calls.
gpshead May 8, 2022
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9 changes: 0 additions & 9 deletions Doc/using/cmdline.rst
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Expand Up @@ -999,15 +999,6 @@ conflict.
Debug-mode variables
~~~~~~~~~~~~~~~~~~~~

.. envvar:: PYTHONTHREADDEBUG

If set, Python will print threading debug info into stdout.

Need a :ref:`debug build of Python <debug-build>`.

.. deprecated-removed:: 3.10 3.12


.. envvar:: PYTHONDUMPREFS

If set, Python will dump objects and reference counts still alive after
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1 change: 0 additions & 1 deletion Doc/using/configure.rst
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Expand Up @@ -278,7 +278,6 @@ Effects of a debug build:
* Add ``d`` to :data:`sys.abiflags`.
* Add :func:`sys.gettotalrefcount` function.
* Add :option:`-X showrefcount <-X>` command line option.
* Add :envvar:`PYTHONTHREADDEBUG` environment variable.
* Add support for the ``__lltrace__`` variable: enable low-level tracing in the
bytecode evaluation loop if the variable is defined.
* Install :ref:`debug hooks on memory allocators <default-memory-allocators>`
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10 changes: 0 additions & 10 deletions Lib/test/test_threading.py
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Expand Up @@ -945,16 +945,6 @@ def noop(): pass
threading.Thread(target=noop).start()
# Thread.join() is not called

@unittest.skipUnless(Py_DEBUG, 'need debug build (Py_DEBUG)')
def test_debug_deprecation(self):
# bpo-44584: The PYTHONTHREADDEBUG environment variable is deprecated
rc, out, err = assert_python_ok("-Wdefault", "-c", "pass",
PYTHONTHREADDEBUG="1")
msg = (b'DeprecationWarning: The threading debug '
b'(PYTHONTHREADDEBUG environment variable) '
b'is deprecated and will be removed in Python 3.12')
self.assertIn(msg, err)

def test_import_from_another_thread(self):
# bpo-1596321: If the threading module is first import from a thread
# different than the main thread, threading._shutdown() must handle
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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2022-05-08-19-43-31.gh-issue-88750.1BjJg-.rst
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@@ -0,0 +1,2 @@
The deprecated debug build only ``PYTHONTHREADDEBUG`` environment variable
no longer does anything.
3 changes: 0 additions & 3 deletions Misc/python.man
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Expand Up @@ -560,9 +560,6 @@ can be set to the callable of your debugger of choice.
Setting these variables only has an effect in a debug build of Python, that is,
if Python was configured with the
\fB\--with-pydebug\fP build option.
.IP PYTHONTHREADDEBUG
If this environment variable is set, Python will print threading debug info.
The feature is deprecated in Python 3.10 and will be removed in Python 3.12.
.IP PYTHONDUMPREFS
If this environment variable is set, Python will dump objects and reference
counts still alive after shutting down the interpreter.
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5 changes: 0 additions & 5 deletions Python/pylifecycle.c
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Expand Up @@ -1091,8 +1091,6 @@ pyinit_main_reconfigure(PyThreadState *tstate)
static PyStatus
init_interp_main(PyThreadState *tstate)
{
extern void _PyThread_debug_deprecation(void);

assert(!_PyErr_Occurred(tstate));

PyStatus status;
Expand Down Expand Up @@ -1194,9 +1192,6 @@ init_interp_main(PyThreadState *tstate)
#endif
}

// Warn about PYTHONTHREADDEBUG deprecation
_PyThread_debug_deprecation();

assert(!_PyErr_Occurred(tstate));

return _PyStatus_OK();
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38 changes: 0 additions & 38 deletions Python/thread.c
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Expand Up @@ -42,57 +42,19 @@

#endif /* _POSIX_THREADS */


#ifdef Py_DEBUG
static int thread_debug = 0;
# define dprintf(args) (void)((thread_debug & 1) && printf args)
#else
# define dprintf(args)
#endif

static int initialized;

static void PyThread__init_thread(void); /* Forward */

void
PyThread_init_thread(void)
{
#ifdef Py_DEBUG
const char *p = Py_GETENV("PYTHONTHREADDEBUG");

if (p) {
if (*p)
thread_debug = atoi(p);
else
thread_debug = 1;
}
#endif /* Py_DEBUG */
if (initialized)
return;
initialized = 1;
dprintf(("PyThread_init_thread called\n"));
PyThread__init_thread();
}

void
_PyThread_debug_deprecation(void)
{
#ifdef Py_DEBUG
if (thread_debug) {
// Flush previous dprintf() logs
fflush(stdout);
if (PyErr_WarnEx(PyExc_DeprecationWarning,
"The threading debug (PYTHONTHREADDEBUG environment "
"variable) is deprecated and will be removed "
"in Python 3.12",
0))
{
_PyErr_WriteUnraisableMsg("at Python startup", NULL);
}
}
#endif
}

#if defined(_POSIX_THREADS)
# define PYTHREAD_NAME "pthread"
# include "thread_pthread.h"
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25 changes: 3 additions & 22 deletions Python/thread_nt.h
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Expand Up @@ -188,8 +188,6 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
unsigned threadID;
callobj *obj;

dprintf(("%lu: PyThread_start_new_thread called\n",
PyThread_get_thread_ident()));
if (!initialized)
PyThread_init_thread();

Expand All @@ -209,14 +207,10 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
* too many threads".
*/
int e = errno;
dprintf(("%lu: PyThread_start_new_thread failed, errno %d\n",
PyThread_get_thread_ident(), e));
threadID = (unsigned)-1;
HeapFree(GetProcessHeap(), 0, obj);
}
else {
dprintf(("%lu: PyThread_start_new_thread succeeded: %p\n",
PyThread_get_thread_ident(), (void*)hThread));
CloseHandle(hThread);
}
return threadID;
Expand Down Expand Up @@ -257,7 +251,6 @@ PyThread_get_thread_native_id(void)
void _Py_NO_RETURN
PyThread_exit_thread(void)
{
dprintf(("%lu: PyThread_exit_thread called\n", PyThread_get_thread_ident()));
if (!initialized)
exit(0);
_endthreadex(0);
Expand All @@ -273,22 +266,17 @@ PyThread_allocate_lock(void)
{
PNRMUTEX aLock;

dprintf(("PyThread_allocate_lock called\n"));
if (!initialized)
PyThread_init_thread();

aLock = AllocNonRecursiveMutex() ;

dprintf(("%lu: PyThread_allocate_lock() -> %p\n", PyThread_get_thread_ident(), aLock));

return (PyThread_type_lock) aLock;
}

void
PyThread_free_lock(PyThread_type_lock aLock)
{
dprintf(("%lu: PyThread_free_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

FreeNonRecursiveMutex(aLock) ;
}

Expand Down Expand Up @@ -333,9 +321,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock aLock,
milliseconds = INFINITE;
}

dprintf(("%lu: PyThread_acquire_lock_timed(%p, %lld) called\n",
PyThread_get_thread_ident(), aLock, microseconds));

if (aLock && EnterNonRecursiveMutex((PNRMUTEX)aLock,
(DWORD)milliseconds) == WAIT_OBJECT_0) {
success = PY_LOCK_ACQUIRED;
Expand All @@ -344,9 +329,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock aLock,
success = PY_LOCK_FAILURE;
}

dprintf(("%lu: PyThread_acquire_lock(%p, %lld) -> %d\n",
PyThread_get_thread_ident(), aLock, microseconds, success));

return success;
}
int
Expand All @@ -358,10 +340,9 @@ PyThread_acquire_lock(PyThread_type_lock aLock, int waitflag)
void
PyThread_release_lock(PyThread_type_lock aLock)
{
dprintf(("%lu: PyThread_release_lock(%p) called\n", PyThread_get_thread_ident(),aLock));

if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock)))
dprintf(("%lu: Could not PyThread_release_lock(%p) error: %ld\n", PyThread_get_thread_ident(), aLock, GetLastError()));
if (aLock) {
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Wait, we have a special case to do nothing if the lock is not initialized? Only for the Windows implementation and only for PyThread_release_lock()? That's weird. I suggest to replace the if() with an assert(), but done in a separated PR. (I can do it if I don't forget.)

It's weird because the pthread implement has no special case for PyThread_release_lock() and so the code is not portable. Or maybe I misunderstood something.

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I'd be surprised to ever see this called with aLock == NULL, I just figured I should preserve the exact semantics when removing the debug print. Agreed on the assert, but that does make more sense in a followup PR.

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Sure. I created #92586

(void)LeaveNonRecursiveMutex((PNRMUTEX) aLock);
}
}

/* minimum/maximum thread stack sizes supported */
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19 changes: 0 additions & 19 deletions Python/thread_pthread.h
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Expand Up @@ -252,7 +252,6 @@ PyThread_start_new_thread(void (*func)(void *), void *arg)
size_t tss;
#endif

dprintf(("PyThread_start_new_thread called\n"));
if (!initialized)
PyThread_init_thread();

Expand Down Expand Up @@ -358,7 +357,6 @@ PyThread_get_thread_native_id(void)
void _Py_NO_RETURN
PyThread_exit_thread(void)
{
dprintf(("PyThread_exit_thread called\n"));
if (!initialized)
exit(0);
pthread_exit(0);
Expand All @@ -376,7 +374,6 @@ PyThread_allocate_lock(void)
sem_t *lock;
int status, error = 0;

dprintf(("PyThread_allocate_lock called\n"));
if (!initialized)
PyThread_init_thread();

Expand All @@ -392,7 +389,6 @@ PyThread_allocate_lock(void)
}
}

dprintf(("PyThread_allocate_lock() -> %p\n", (void *)lock));
return (PyThread_type_lock)lock;
}

Expand All @@ -403,7 +399,6 @@ PyThread_free_lock(PyThread_type_lock lock)
int status, error = 0;

(void) error; /* silence unused-but-set-variable warning */
dprintf(("PyThread_free_lock(%p) called\n", lock));

if (!thelock)
return;
Expand Down Expand Up @@ -435,8 +430,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds,
int status, error = 0;

(void) error; /* silence unused-but-set-variable warning */
dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) called\n",
lock, microseconds, intr_flag));

_PyTime_t timeout; // relative timeout
if (microseconds >= 0) {
Expand Down Expand Up @@ -544,8 +537,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds,
success = PY_LOCK_FAILURE;
}

dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) -> %d\n",
lock, microseconds, intr_flag, success));
return success;
}

Expand All @@ -556,7 +547,6 @@ PyThread_release_lock(PyThread_type_lock lock)
int status, error = 0;

(void) error; /* silence unused-but-set-variable warning */
dprintf(("PyThread_release_lock(%p) called\n", lock));

status = sem_post(thelock);
CHECK_STATUS("sem_post");
Expand All @@ -573,7 +563,6 @@ PyThread_allocate_lock(void)
pthread_lock *lock;
int status, error = 0;

dprintf(("PyThread_allocate_lock called\n"));
if (!initialized)
PyThread_init_thread();

Expand All @@ -599,7 +588,6 @@ PyThread_allocate_lock(void)
}
}

dprintf(("PyThread_allocate_lock() -> %p\n", (void *)lock));
return (PyThread_type_lock) lock;
}

Expand All @@ -610,7 +598,6 @@ PyThread_free_lock(PyThread_type_lock lock)
int status, error = 0;

(void) error; /* silence unused-but-set-variable warning */
dprintf(("PyThread_free_lock(%p) called\n", lock));

/* some pthread-like implementations tie the mutex to the cond
* and must have the cond destroyed first.
Expand All @@ -632,9 +619,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds,
pthread_lock *thelock = (pthread_lock *)lock;
int status, error = 0;

dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) called\n",
lock, microseconds, intr_flag));

if (microseconds == 0) {
status = pthread_mutex_trylock( &thelock->mut );
if (status != EBUSY)
Expand Down Expand Up @@ -694,8 +678,6 @@ PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds,
}

if (error) success = PY_LOCK_FAILURE;
dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) -> %d\n",
lock, microseconds, intr_flag, success));
return success;
}

Expand All @@ -706,7 +688,6 @@ PyThread_release_lock(PyThread_type_lock lock)
int status, error = 0;

(void) error; /* silence unused-but-set-variable warning */
dprintf(("PyThread_release_lock(%p) called\n", lock));

status = pthread_mutex_lock( &thelock->mut );
CHECK_STATUS_PTHREAD("pthread_mutex_lock[3]");
Expand Down