bpo-33608: Minor cleanup related to pending calls. (gh-12247)

`@@ -174,9 +174,11 @@ PyEval_InitThreads(void)

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`PyThread_init_thread();

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`create_gil();

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`take_gil(_PyThreadState_GET());

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_PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();

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if (!_PyRuntime.ceval.pending.lock)

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// Set it to the ID of the main thread of the main interpreter.

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_PyRuntime.main_thread = PyThread_get_thread_ident();

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if (!_PyRuntime.ceval.pending.lock) {

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`_PyRuntime.ceval.pending.lock = PyThread_allocate_lock();

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}

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`void

`@@ -243,9 +245,9 @@ PyEval_ReInitThreads(void)

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`if (!gil_created())

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`return;

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`recreate_gil();

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_PyRuntime.ceval.pending.lock = PyThread_allocate_lock();

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`take_gil(current_tstate);

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_PyRuntime.ceval.pending.main_thread = PyThread_get_thread_ident();

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_PyRuntime.main_thread = PyThread_get_thread_ident();

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_PyRuntime.ceval.pending.lock = PyThread_allocate_lock();

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`/* Destroy all threads except the current one */

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`_PyThreadState_DeleteExcept(current_tstate);

`@@ -323,6 +325,35 @@ _PyEval_SignalReceived(void)

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`SIGNAL_PENDING_SIGNALS();

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/* Push one item onto the queue while holding the lock. */

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static int

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_push_pending_call(int (*func)(void *), void *arg)

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{

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int i = _PyRuntime.ceval.pending.last;

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int j = (i + 1) % NPENDINGCALLS;

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if (j == _PyRuntime.ceval.pending.first) {

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return -1; /* Queue full */

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}

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_PyRuntime.ceval.pending.calls[i].func = func;

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_PyRuntime.ceval.pending.calls[i].arg = arg;

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_PyRuntime.ceval.pending.last = j;

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return 0;

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}

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+

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/* Pop one item off the queue while holding the lock. */

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static void

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_pop_pending_call(int (**func)(void *), void **arg)

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{

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int i = _PyRuntime.ceval.pending.first;

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if (i == _PyRuntime.ceval.pending.last) {

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return; /* Queue empty */

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}

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+

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*func = _PyRuntime.ceval.pending.calls[i].func;

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*arg = _PyRuntime.ceval.pending.calls[i].arg;

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_PyRuntime.ceval.pending.first = (i + 1) % NPENDINGCALLS;

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}

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+

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`/* This implementation is thread-safe. It allows

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` scheduling to be made from any thread, and even from an executing

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` callback.

`@@ -331,7 +362,6 @@ _PyEval_SignalReceived(void)

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`int

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`Py_AddPendingCall(int (*func)(void *), void *arg)

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int i, j, result=0;

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`PyThread_type_lock lock = _PyRuntime.ceval.pending.lock;

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`/* try a few times for the lock. Since this mechanism is used

`@@ -346,6 +376,7 @@ Py_AddPendingCall(int (*func)(void *), void *arg)

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` * this function is called before any bytecode evaluation takes place.

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` */

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`if (lock != NULL) {

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int i;

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`for (i = 0; i<100; i++) {

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`if (PyThread_acquire_lock(lock, NOWAIT_LOCK))

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`break;

`@@ -354,15 +385,8 @@ Py_AddPendingCall(int (*func)(void *), void *arg)

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`return -1;

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` }

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i = _PyRuntime.ceval.pending.last;

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j = (i + 1) % NPENDINGCALLS;

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if (j == _PyRuntime.ceval.pending.first) {

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result = -1; /* Queue full */

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} else {

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_PyRuntime.ceval.pending.calls[i].func = func;

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_PyRuntime.ceval.pending.calls[i].arg = arg;

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_PyRuntime.ceval.pending.last = j;

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}

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int result = _push_pending_call(func, arg);

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+

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`/* signal main loop */

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`SIGNAL_PENDING_CALLS();

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`if (lock != NULL)

`@@ -373,10 +397,10 @@ Py_AddPendingCall(int (*func)(void *), void *arg)

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`static int

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`handle_signals(void)

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/* Only handle signals on main thread. */

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if (_PyRuntime.ceval.pending.main_thread &&

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PyThread_get_thread_ident() != _PyRuntime.ceval.pending.main_thread)

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{

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/* Only handle signals on main thread. PyEval_InitThreads must

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have been called already.

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if (PyThread_get_thread_ident() != _PyRuntime.main_thread) {

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`return 0;

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` }

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`/*

`@@ -401,9 +425,7 @@ make_pending_calls(void)

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`static int busy = 0;

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`/* only service pending calls on main thread */

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if (_PyRuntime.ceval.pending.main_thread &&

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PyThread_get_thread_ident() != _PyRuntime.ceval.pending.main_thread)

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{

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if (PyThread_get_thread_ident() != _PyRuntime.main_thread) {

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`return 0;

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` }

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`@@ -428,24 +450,18 @@ make_pending_calls(void)

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`/* perform a bounded number of calls, in case of recursion */

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`for (int i=0; i<NPENDINGCALLS; i++) {

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int j;

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int (*func)(void *);

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int (*func)(void *) = NULL;

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`void *arg = NULL;

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`/* pop one item off the queue while holding the lock */

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`PyThread_acquire_lock(_PyRuntime.ceval.pending.lock, WAIT_LOCK);

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j = _PyRuntime.ceval.pending.first;

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if (j == _PyRuntime.ceval.pending.last) {

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func = NULL; /* Queue empty */

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} else {

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func = _PyRuntime.ceval.pending.calls[j].func;

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arg = _PyRuntime.ceval.pending.calls[j].arg;

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_PyRuntime.ceval.pending.first = (j + 1) % NPENDINGCALLS;

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}

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_pop_pending_call(&func, &arg);

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`PyThread_release_lock(_PyRuntime.ceval.pending.lock);

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+

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`/* having released the lock, perform the callback */

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if (func == NULL)

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if (func == NULL) {

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`break;

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}

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`res = func(arg);

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`if (res) {

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` goto error;

bpo-33608: Minor cleanup related to pending calls. (gh-12247) · python/cpython@5be45a6 (original) (raw)