mirror of
https://github.com/python/cpython.git
synced 2024-12-02 06:14:49 +08:00
2ebc5ce42a
* group the (stateful) runtime globals into various topical structs * consolidate the topical structs under a single top-level _PyRuntimeState struct * add a check-c-globals.py script that helps identify runtime globals Other globals are excluded (see globals.txt and check-c-globals.py).
92 lines
2.7 KiB
C
92 lines
2.7 KiB
C
#ifndef Py_INTERNAL_CONDVAR_H
|
|
#define Py_INTERNAL_CONDVAR_H
|
|
|
|
#ifndef _POSIX_THREADS
|
|
/* This means pthreads are not implemented in libc headers, hence the macro
|
|
not present in unistd.h. But they still can be implemented as an external
|
|
library (e.g. gnu pth in pthread emulation) */
|
|
# ifdef HAVE_PTHREAD_H
|
|
# include <pthread.h> /* _POSIX_THREADS */
|
|
# endif
|
|
#endif
|
|
|
|
#ifdef _POSIX_THREADS
|
|
/*
|
|
* POSIX support
|
|
*/
|
|
#define Py_HAVE_CONDVAR
|
|
|
|
#include <pthread.h>
|
|
|
|
#define PyMUTEX_T pthread_mutex_t
|
|
#define PyCOND_T pthread_cond_t
|
|
|
|
#elif defined(NT_THREADS)
|
|
/*
|
|
* Windows (XP, 2003 server and later, as well as (hopefully) CE) support
|
|
*
|
|
* Emulated condition variables ones that work with XP and later, plus
|
|
* example native support on VISTA and onwards.
|
|
*/
|
|
#define Py_HAVE_CONDVAR
|
|
|
|
/* include windows if it hasn't been done before */
|
|
#define WIN32_LEAN_AND_MEAN
|
|
#include <windows.h>
|
|
|
|
/* options */
|
|
/* non-emulated condition variables are provided for those that want
|
|
* to target Windows Vista. Modify this macro to enable them.
|
|
*/
|
|
#ifndef _PY_EMULATED_WIN_CV
|
|
#define _PY_EMULATED_WIN_CV 1 /* use emulated condition variables */
|
|
#endif
|
|
|
|
/* fall back to emulation if not targeting Vista */
|
|
#if !defined NTDDI_VISTA || NTDDI_VERSION < NTDDI_VISTA
|
|
#undef _PY_EMULATED_WIN_CV
|
|
#define _PY_EMULATED_WIN_CV 1
|
|
#endif
|
|
|
|
#if _PY_EMULATED_WIN_CV
|
|
|
|
typedef CRITICAL_SECTION PyMUTEX_T;
|
|
|
|
/* The ConditionVariable object. From XP onwards it is easily emulated
|
|
with a Semaphore.
|
|
Semaphores are available on Windows XP (2003 server) and later.
|
|
We use a Semaphore rather than an auto-reset event, because although
|
|
an auto-resent event might appear to solve the lost-wakeup bug (race
|
|
condition between releasing the outer lock and waiting) because it
|
|
maintains state even though a wait hasn't happened, there is still
|
|
a lost wakeup problem if more than one thread are interrupted in the
|
|
critical place. A semaphore solves that, because its state is
|
|
counted, not Boolean.
|
|
Because it is ok to signal a condition variable with no one
|
|
waiting, we need to keep track of the number of
|
|
waiting threads. Otherwise, the semaphore's state could rise
|
|
without bound. This also helps reduce the number of "spurious wakeups"
|
|
that would otherwise happen.
|
|
*/
|
|
|
|
typedef struct _PyCOND_T
|
|
{
|
|
HANDLE sem;
|
|
int waiting; /* to allow PyCOND_SIGNAL to be a no-op */
|
|
} PyCOND_T;
|
|
|
|
#else /* !_PY_EMULATED_WIN_CV */
|
|
|
|
/* Use native Win7 primitives if build target is Win7 or higher */
|
|
|
|
/* SRWLOCK is faster and better than CriticalSection */
|
|
typedef SRWLOCK PyMUTEX_T;
|
|
|
|
typedef CONDITION_VARIABLE PyCOND_T;
|
|
|
|
#endif /* _PY_EMULATED_WIN_CV */
|
|
|
|
#endif /* _POSIX_THREADS, NT_THREADS */
|
|
|
|
#endif /* Py_INTERNAL_CONDVAR_H */
|