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0e9c364f4a
Joining a thread now ensures the underlying OS thread has exited. This is required for safer fork() in multi-threaded processes. --------- Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
155 lines
5.2 KiB
C
155 lines
5.2 KiB
C
#ifndef Py_INTERNAL_PYTHREAD_H
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#define Py_INTERNAL_PYTHREAD_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 "dynamic_annotations.h" // _Py_ANNOTATE_PURE_HAPPENS_BEFORE_MUTEX
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// Get _POSIX_THREADS and _POSIX_SEMAPHORES macros if available
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#if (defined(HAVE_UNISTD_H) && !defined(_POSIX_THREADS) \
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&& !defined(_POSIX_SEMAPHORES))
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# include <unistd.h> // _POSIX_THREADS, _POSIX_SEMAPHORES
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#endif
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#if (defined(HAVE_PTHREAD_H) && !defined(_POSIX_THREADS) \
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&& !defined(_POSIX_SEMAPHORES))
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// This means pthreads are not implemented in libc headers, hence the macro
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// not present in <unistd.h>. But they still can be implemented as an
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// external library (e.g. gnu pth in pthread emulation)
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# include <pthread.h> // _POSIX_THREADS, _POSIX_SEMAPHORES
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#endif
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#if !defined(_POSIX_THREADS) && defined(__hpux) && defined(_SC_THREADS)
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// Check if we're running on HP-UX and _SC_THREADS is defined. If so, then
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// enough of the POSIX threads package is implemented to support Python
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// threads.
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//
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// This is valid for HP-UX 11.23 running on an ia64 system. If needed, add
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// a check of __ia64 to verify that we're running on an ia64 system instead
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// of a pa-risc system.
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# define _POSIX_THREADS
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#endif
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#if defined(_POSIX_THREADS) || defined(HAVE_PTHREAD_STUBS)
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# define _USE_PTHREADS
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#endif
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#if defined(_USE_PTHREADS) && defined(HAVE_PTHREAD_CONDATTR_SETCLOCK) && defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
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// monotonic is supported statically. It doesn't mean it works on runtime.
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# define CONDATTR_MONOTONIC
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#endif
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#if defined(HAVE_PTHREAD_STUBS)
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#include <stdbool.h> // bool
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// pthread_key
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struct py_stub_tls_entry {
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bool in_use;
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void *value;
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};
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#endif
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struct _pythread_runtime_state {
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int initialized;
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#ifdef _USE_PTHREADS
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// This matches when thread_pthread.h is used.
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struct {
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/* NULL when pthread_condattr_setclock(CLOCK_MONOTONIC) is not supported. */
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pthread_condattr_t *ptr;
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# ifdef CONDATTR_MONOTONIC
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/* The value to which condattr_monotonic is set. */
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pthread_condattr_t val;
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# endif
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} _condattr_monotonic;
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#endif // USE_PTHREADS
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#if defined(HAVE_PTHREAD_STUBS)
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struct {
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struct py_stub_tls_entry tls_entries[PTHREAD_KEYS_MAX];
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} stubs;
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#endif
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};
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#ifdef HAVE_FORK
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/* Private function to reinitialize a lock at fork in the child process.
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Reset the lock to the unlocked state.
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Return 0 on success, return -1 on error. */
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extern int _PyThread_at_fork_reinit(PyThread_type_lock *lock);
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#endif /* HAVE_FORK */
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// unset: -1 seconds, in nanoseconds
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#define PyThread_UNSET_TIMEOUT ((_PyTime_t)(-1 * 1000 * 1000 * 1000))
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// Exported for the _xxinterpchannels module.
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PyAPI_FUNC(int) PyThread_ParseTimeoutArg(
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PyObject *arg,
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int blocking,
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PY_TIMEOUT_T *timeout);
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/* Helper to acquire an interruptible lock with a timeout. If the lock acquire
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* is interrupted, signal handlers are run, and if they raise an exception,
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* PY_LOCK_INTR is returned. Otherwise, PY_LOCK_ACQUIRED or PY_LOCK_FAILURE
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* are returned, depending on whether the lock can be acquired within the
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* timeout.
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*/
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// Exported for the _xxinterpchannels module.
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PyAPI_FUNC(PyLockStatus) PyThread_acquire_lock_timed_with_retries(
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PyThread_type_lock,
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PY_TIMEOUT_T microseconds);
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typedef unsigned long long PyThread_ident_t;
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typedef Py_uintptr_t PyThread_handle_t;
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#define PY_FORMAT_THREAD_IDENT_T "llu"
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#define Py_PARSE_THREAD_IDENT_T "K"
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PyAPI_FUNC(PyThread_ident_t) PyThread_get_thread_ident_ex(void);
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/* Thread joining APIs.
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*
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* These APIs have a strict contract:
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* - Either PyThread_join_thread or PyThread_detach_thread must be called
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* exactly once with the given handle.
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* - Calling neither PyThread_join_thread nor PyThread_detach_thread results
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* in a resource leak until the end of the process.
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* - Any other usage, such as calling both PyThread_join_thread and
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* PyThread_detach_thread, or calling them more than once (including
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* simultaneously), results in undefined behavior.
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*/
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PyAPI_FUNC(int) PyThread_start_joinable_thread(void (*func)(void *),
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void *arg,
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PyThread_ident_t* ident,
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PyThread_handle_t* handle);
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/*
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* Join a thread started with `PyThread_start_joinable_thread`.
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* This function cannot be interrupted. It returns 0 on success,
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* a non-zero value on failure.
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*/
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PyAPI_FUNC(int) PyThread_join_thread(PyThread_handle_t);
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/*
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* Detach a thread started with `PyThread_start_joinable_thread`, such
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* that its resources are relased as soon as it exits.
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* This function cannot be interrupted. It returns 0 on success,
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* a non-zero value on failure.
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*/
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PyAPI_FUNC(int) PyThread_detach_thread(PyThread_handle_t);
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/*
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* Obtain the new thread ident and handle in a forked child process.
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*/
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PyAPI_FUNC(void) PyThread_update_thread_after_fork(PyThread_ident_t* ident,
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PyThread_handle_t* handle);
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#ifdef __cplusplus
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}
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#endif
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#endif /* !Py_INTERNAL_PYTHREAD_H */
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