diff options
author | Bruno Haible <bruno@clisp.org> | 2019-06-20 04:12:41 +0200 |
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committer | Bruno Haible <bruno@clisp.org> | 2019-06-20 04:13:13 +0200 |
commit | f46ac2b2b4635118957a5718a125016f4ec15a8a (patch) | |
tree | e10b95393df5a03ceaf92b3e1c38bc5ffc095fe7 /lib | |
parent | d20c7ec39fb2adbaf9bb3a3cc608019fee678870 (diff) | |
download | gnulib-f46ac2b2b4635118957a5718a125016f4ec15a8a.tar.gz |
windows-timedrecmutex: New module.
* lib/windows-timedrecmutex.h: New file, based on windows-recmutex.h.
* lib/windows-timedrecmutex.c: New file, based on windows-recmutex.c.
* modules/windows-timedrecmutex: New file.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/windows-timedrecmutex.c | 267 | ||||
-rw-r--r-- | lib/windows-timedrecmutex.h | 62 |
2 files changed, 329 insertions, 0 deletions
diff --git a/lib/windows-timedrecmutex.c b/lib/windows-timedrecmutex.c new file mode 100644 index 0000000000..6f91d46daa --- /dev/null +++ b/lib/windows-timedrecmutex.c @@ -0,0 +1,267 @@ +/* Timed recursive mutexes (native Windows implementation). + Copyright (C) 2005-2019 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2005, 2019. + Based on GCC's gthr-win32.h. */ + +#include <config.h> + +/* Specification. */ +#include "windows-timedrecmutex.h" + +#include <errno.h> +#include <stdlib.h> +#include <sys/time.h> + +int +glwthread_timedrecmutex_init (glwthread_timedrecmutex_t *mutex) +{ + mutex->owner = 0; + mutex->depth = 0; + /* Attempt to allocate an auto-reset event object. */ + /* CreateEvent + <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-createeventa> */ + HANDLE event = CreateEvent (NULL, FALSE, FALSE, NULL); + if (event == INVALID_HANDLE_VALUE) + return EAGAIN; + mutex->event = event; + InitializeCriticalSection (&mutex->lock); + mutex->guard.done = 1; + return 0; +} + +int +glwthread_timedrecmutex_lock (glwthread_timedrecmutex_t *mutex) +{ + if (!mutex->guard.done) + { + if (InterlockedIncrement (&mutex->guard.started) == 0) + { + /* This thread is the first one to need this mutex. + Initialize it. */ + int err = glwthread_timedrecmutex_init (mutex); + if (err != 0) + { + /* Undo increment. */ + InterlockedDecrement (&mutex->guard.started); + return err; + } + } + else + { + /* Don't let mutex->guard.started grow and wrap around. */ + InterlockedDecrement (&mutex->guard.started); + /* Yield the CPU while waiting for another thread to finish + initializing this mutex. */ + while (!mutex->guard.done) + Sleep (0); + } + } + { + DWORD self = GetCurrentThreadId (); + if (mutex->owner != self) + { + EnterCriticalSection (&mutex->lock); + mutex->owner = self; + } + if (++(mutex->depth) == 0) /* wraparound? */ + { + mutex->depth--; + return EAGAIN; + } + } + return 0; +} + +int +glwthread_timedrecmutex_trylock (glwthread_timedrecmutex_t *mutex) +{ + if (!mutex->guard.done) + { + if (InterlockedIncrement (&mutex->guard.started) == 0) + { + /* This thread is the first one to need this mutex. + Initialize it. */ + int err = glwthread_timedrecmutex_init (mutex); + if (err != 0) + { + /* Undo increment. */ + InterlockedDecrement (&mutex->guard.started); + return err; + } + } + else + { + /* Don't let mutex->guard.started grow and wrap around. */ + InterlockedDecrement (&mutex->guard.started); + /* Let another thread finish initializing this mutex, and let it also + lock this mutex. */ + return EBUSY; + } + } + { + DWORD self = GetCurrentThreadId (); + if (mutex->owner != self) + { + if (!TryEnterCriticalSection (&mutex->lock)) + return EBUSY; + mutex->owner = self; + } + if (++(mutex->depth) == 0) /* wraparound? */ + { + mutex->depth--; + return EAGAIN; + } + } + return 0; +} + +int +glwthread_timedrecmutex_timedlock (glwthread_timedrecmutex_t *mutex, + const struct timespec *abstime) +{ + if (!mutex->guard.done) + { + if (InterlockedIncrement (&mutex->guard.started) == 0) + { + /* This thread is the first one to need this mutex. + Initialize it. */ + int err = glwthread_timedrecmutex_init (mutex); + if (err != 0) + { + /* Undo increment. */ + InterlockedDecrement (&mutex->guard.started); + return err; + } + } + else + { + /* Don't let mutex->guard.started grow and wrap around. */ + InterlockedDecrement (&mutex->guard.started); + /* Yield the CPU while waiting for another thread to finish + initializing this mutex. */ + while (!mutex->guard.done) + Sleep (0); + } + } + + { + DWORD self = GetCurrentThreadId (); + if (mutex->owner != self) + { + /* POSIX says: + "Under no circumstance shall the function fail with a timeout if + the mutex can be locked immediately. The validity of the abstime + parameter need not be checked if the mutex can be locked + immediately." + Therefore start the loop with a TryEnterCriticalSection call. */ + for (;;) + { + if (TryEnterCriticalSection (&mutex->lock)) + break; + + { + struct timeval currtime; + DWORD timeout; + DWORD result; + + gettimeofday (&currtime, NULL); + + /* Wait until another thread signals the event or until the + abstime passes. */ + if (currtime.tv_sec > abstime->tv_sec) + timeout = 0; + else + { + unsigned long seconds = abstime->tv_sec - currtime.tv_sec; + timeout = seconds * 1000; + if (timeout / 1000 != seconds) /* overflow? */ + timeout = INFINITE; + else + { + long milliseconds = + abstime->tv_nsec / 1000000 - currtime.tv_usec / 1000; + if (milliseconds >= 0) + { + timeout += milliseconds; + if (timeout < milliseconds) /* overflow? */ + timeout = INFINITE; + } + else + { + if (timeout >= - milliseconds) + timeout -= (- milliseconds); + else + timeout = 0; + } + } + } + if (timeout == 0) + return ETIMEDOUT; + + /* WaitForSingleObject + <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-waitforsingleobject> */ + result = WaitForSingleObject (mutex->event, timeout); + if (result == WAIT_FAILED) + abort (); + if (result == WAIT_TIMEOUT) + return ETIMEDOUT; + /* Another thread has just unlocked the mutex. We have good chances at + locking it now. */ + } + } + mutex->owner = self; + } + if (++(mutex->depth) == 0) /* wraparound? */ + { + mutex->depth--; + return EAGAIN; + } + } + return 0; +} + +int +glwthread_timedrecmutex_unlock (glwthread_timedrecmutex_t *mutex) +{ + if (mutex->owner != GetCurrentThreadId ()) + return EPERM; + if (mutex->depth == 0) + return EINVAL; + if (--(mutex->depth) == 0) + { + mutex->owner = 0; + LeaveCriticalSection (&mutex->lock); + /* Notify one of the threads that were waiting with a timeout. */ + /* SetEvent + <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-setevent> */ + SetEvent (mutex->event); + } + return 0; +} + +int +glwthread_timedrecmutex_destroy (glwthread_timedrecmutex_t *mutex) +{ + if (mutex->owner != 0) + return EBUSY; + DeleteCriticalSection (&mutex->lock); + /* CloseHandle + <https://docs.microsoft.com/en-us/windows/desktop/api/handleapi/nf-handleapi-closehandle> */ + CloseHandle (mutex->event); + mutex->guard.done = 0; + return 0; +} diff --git a/lib/windows-timedrecmutex.h b/lib/windows-timedrecmutex.h new file mode 100644 index 0000000000..c0d2d3b75a --- /dev/null +++ b/lib/windows-timedrecmutex.h @@ -0,0 +1,62 @@ +/* Timed recursive mutexes (native Windows implementation). + Copyright (C) 2005-2019 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2005, 2019. + Based on GCC's gthr-win32.h. */ + +#ifndef _WINDOWS_TIMEDRECMUTEX_H +#define _WINDOWS_TIMEDRECMUTEX_H + +#define WIN32_LEAN_AND_MEAN /* avoid including junk */ +#include <windows.h> + +#include <time.h> + +#include "windows-spinlock.h" + +/* The native Windows documentation says that CRITICAL_SECTION already + implements a recursive lock. But we need not rely on it: It's easy to + implement a recursive lock without this assumption. */ + +typedef struct + { + glwthread_spinlock_t guard; /* protects the initialization */ + DWORD owner; + unsigned long depth; + HANDLE event; + CRITICAL_SECTION lock; + } + glwthread_timedrecmutex_t; + +#define GLWTHREAD_TIMEDRECMUTEX_INIT { GLWTHREAD_SPINLOCK_INIT, 0, 0 } + +#ifdef __cplusplus +extern "C" { +#endif + +extern int glwthread_timedrecmutex_init (glwthread_timedrecmutex_t *mutex); +extern int glwthread_timedrecmutex_lock (glwthread_timedrecmutex_t *mutex); +extern int glwthread_timedrecmutex_trylock (glwthread_timedrecmutex_t *mutex); +extern int glwthread_timedrecmutex_timedlock (glwthread_timedrecmutex_t *mutex, + const struct timespec *abstime); +extern int glwthread_timedrecmutex_unlock (glwthread_timedrecmutex_t *mutex); +extern int glwthread_timedrecmutex_destroy (glwthread_timedrecmutex_t *mutex); + +#ifdef __cplusplus +} +#endif + +#endif /* _WINDOWS_TIMEDRECMUTEX_H */ |