cpython/Python/thread.c at main · https-github-com-nzysoft/cpython · GitHub

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/* Thread package.

This is intended to be usable independently from Python.

The implementation for system foobar is in a file thread_foobar.h

which is included by this file dependent on config settings.

Stuff shared by all thread_*.h files is collected here. */

#include "Python.h"

#include "pycore_ceval.h" // _PyEval_MakePendingCalls()

#include "pycore_pystate.h" // _PyInterpreterState_GET()

#include "pycore_structseq.h" // _PyStructSequence_FiniBuiltin()

#include "pycore_pythread.h" // _POSIX_THREADS

#ifndef DONT_HAVE_STDIO_H

# include <stdio.h>

#endif

#include <stdlib.h>

// Define PY_TIMEOUT_MAX constant.

#ifdef _POSIX_THREADS

// PyThread_acquire_lock_timed() uses _PyTime_FromNanoseconds(us * 1000),

// convert microseconds to nanoseconds.

# define PY_TIMEOUT_MAX_VALUE (LLONG_MAX / 1000)

#elif defined (NT_THREADS)

// WaitForSingleObject() accepts timeout in milliseconds in the range

// [0; 0xFFFFFFFE] (DWORD type). INFINITE value (0xFFFFFFFF) means no

// timeout. 0xFFFFFFFE milliseconds is around 49.7 days.

# if 0xFFFFFFFELL < LLONG_MAX / 1000

# define PY_TIMEOUT_MAX_VALUE (0xFFFFFFFELL * 1000)

# else

# define PY_TIMEOUT_MAX_VALUE LLONG_MAX

# endif

#else

# define PY_TIMEOUT_MAX_VALUE LLONG_MAX

#endif

const long long PY_TIMEOUT_MAX = PY_TIMEOUT_MAX_VALUE;

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

#define initialized _PyRuntime.threads.initialized

void

PyThread_init_thread(void)

{

if (initialized) {

return;

}

initialized = 1;

PyThread__init_thread();

}

#if defined(HAVE_PTHREAD_STUBS)

# define PYTHREAD_NAME "pthread-stubs"

# include "thread_pthread_stubs.h"

#elif defined(_USE_PTHREADS) /* AKA _PTHREADS */

# if defined(__EMSCRIPTEN__) && !defined(__EMSCRIPTEN_PTHREADS__)

# define PYTHREAD_NAME "pthread-stubs"

# else

# define PYTHREAD_NAME "pthread"

# endif

# include "thread_pthread.h"

#elif defined(NT_THREADS)

# define PYTHREAD_NAME "nt"

# include "thread_nt.h"

#else

# error "Require native threads. See https://bugs.python.org/issue31370"

#endif

/* return the current thread stack size */

size_t

PyThread_get_stacksize(void)

{

return _PyInterpreterState_GET()->threads.stacksize;

}

/* Only platforms defining a THREAD_SET_STACKSIZE() macro

in thread_<platform>.h support changing the stack size.

Return 0 if stack size is valid,

-1 if stack size value is invalid,

-2 if setting stack size is not supported. */

int

PyThread_set_stacksize(size_t size)

{

#if defined(THREAD_SET_STACKSIZE)

return THREAD_SET_STACKSIZE(size);

#else

return -2;

#endif

}

int

PyThread_ParseTimeoutArg(PyObject *arg, int blocking, PY_TIMEOUT_T *timeout_p)

{

assert(_PyTime_FromSeconds(-1) == PyThread_UNSET_TIMEOUT);

if (arg == NULL || arg == Py_None) {

*timeout_p = blocking ? PyThread_UNSET_TIMEOUT : 0;

return 0;

}

if (!blocking) {

PyErr_SetString(PyExc_ValueError,

"can't specify a timeout for a non-blocking call");

return -1;

}

_PyTime_t timeout;

if (_PyTime_FromSecondsObject(&timeout, arg, _PyTime_ROUND_TIMEOUT) < 0) {

return -1;

}

if (timeout < 0) {

PyErr_SetString(PyExc_ValueError,

"timeout value must be a non-negative number");

return -1;

}

if (_PyTime_AsMicroseconds(timeout,

_PyTime_ROUND_TIMEOUT) > PY_TIMEOUT_MAX) {

PyErr_SetString(PyExc_OverflowError,

"timeout value is too large");

return -1;

}

*timeout_p = timeout;

return 0;

}

PyLockStatus

PyThread_acquire_lock_timed_with_retries(PyThread_type_lock lock,

PY_TIMEOUT_T timeout)

{

PyThreadState *tstate = _PyThreadState_GET();

_PyTime_t endtime = 0;

if (timeout > 0) {

endtime = _PyDeadline_Init(timeout);

}

PyLockStatus r;

do {

_PyTime_t microseconds;

microseconds = _PyTime_AsMicroseconds(timeout, _PyTime_ROUND_CEILING);

/* first a simple non-blocking try without releasing the GIL */

r = PyThread_acquire_lock_timed(lock, 0, 0);

if (r == PY_LOCK_FAILURE && microseconds != 0) {

Py_BEGIN_ALLOW_THREADS

r = PyThread_acquire_lock_timed(lock, microseconds, 1);

Py_END_ALLOW_THREADS

}

if (r == PY_LOCK_INTR) {

/* Run signal handlers if we were interrupted. Propagate

* exceptions from signal handlers, such as KeyboardInterrupt, by

* passing up PY_LOCK_INTR. */

if (_PyEval_MakePendingCalls(tstate) < 0) {

return PY_LOCK_INTR;

}

/* If we're using a timeout, recompute the timeout after processing

* signals, since those can take time. */

if (timeout > 0) {

timeout = _PyDeadline_Get(endtime);

/* Check for negative values, since those mean block forever.

if (timeout < 0) {

r = PY_LOCK_FAILURE;

}

} while (r == PY_LOCK_INTR); /* Retry if we were interrupted. */

return r;

}

/* Thread Specific Storage (TSS) API

Cross-platform components of TSS API implementation.

Py_tss_t *

PyThread_tss_alloc(void)

{

Py_tss_t *new_key = (Py_tss_t *)PyMem_RawMalloc(sizeof(Py_tss_t));

if (new_key == NULL) {

return NULL;

}

new_key->_is_initialized = 0;

return new_key;

}

void

PyThread_tss_free(Py_tss_t *key)

{

if (key != NULL) {

PyThread_tss_delete(key);

PyMem_RawFree((void *)key);

}

int

PyThread_tss_is_created(Py_tss_t *key)

{

assert(key != NULL);

return key->_is_initialized;

}

PyDoc_STRVAR(threadinfo__doc__,

"sys.thread_info\n\

\n\

A named tuple holding information about the thread implementation.");

static PyStructSequence_Field threadinfo_fields[] = {

{"name", "name of the thread implementation"},

{"lock", "name of the lock implementation"},

{"version", "name and version of the thread library"},

{0}

};

static PyStructSequence_Desc threadinfo_desc = {

"sys.thread_info", /* name */

threadinfo__doc__, /* doc */

threadinfo_fields, /* fields */

};

static PyTypeObject ThreadInfoType;

PyObject*

PyThread_GetInfo(void)

{

PyObject *threadinfo, *value;

int pos = 0;

#if (defined(_POSIX_THREADS) && defined(HAVE_CONFSTR) \

&& defined(_CS_GNU_LIBPTHREAD_VERSION))

char buffer[255];

int len;

#endif

PyInterpreterState *interp = _PyInterpreterState_GET();

if (_PyStructSequence_InitBuiltin(interp, &ThreadInfoType, &threadinfo_desc) < 0) {

return NULL;

}

threadinfo = PyStructSequence_New(&ThreadInfoType);

if (threadinfo == NULL)

return NULL;

value = PyUnicode_FromString(PYTHREAD_NAME);

if (value == NULL) {

Py_DECREF(threadinfo);

return NULL;

}

PyStructSequence_SET_ITEM(threadinfo, pos++, value);

#ifdef HAVE_PTHREAD_STUBS

value = Py_NewRef(Py_None);

#elif defined(_POSIX_THREADS)

#ifdef USE_SEMAPHORES

value = PyUnicode_FromString("semaphore");

#else

value = PyUnicode_FromString("mutex+cond");

#endif

if (value == NULL) {

Py_DECREF(threadinfo);

return NULL;

}

#else

value = Py_NewRef(Py_None);

#endif

PyStructSequence_SET_ITEM(threadinfo, pos++, value);

#if (defined(_POSIX_THREADS) && defined(HAVE_CONFSTR) \

&& defined(_CS_GNU_LIBPTHREAD_VERSION))

value = NULL;

len = confstr(_CS_GNU_LIBPTHREAD_VERSION, buffer, sizeof(buffer));

if (1 < len && (size_t)len < sizeof(buffer)) {

value = PyUnicode_DecodeFSDefaultAndSize(buffer, len-1);

if (value == NULL)

PyErr_Clear();

}

if (value == NULL)

#endif

{

value = Py_NewRef(Py_None);

}

PyStructSequence_SET_ITEM(threadinfo, pos++, value);

return threadinfo;

}

void

_PyThread_FiniType(PyInterpreterState *interp)

{

_PyStructSequence_FiniBuiltin(interp, &ThreadInfoType);

}

cpython/Python/thread.c at main · https-github-com-nzysoft/cpython · GitHub

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