diff options
author | Jörg Frings-Fürst <debian@jff.email> | 2022-02-07 06:57:44 +0100 |
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committer | Jörg Frings-Fürst <debian@jff.email> | 2022-02-07 06:57:44 +0100 |
commit | 6ffaa52cf732a84c0f8259dbc9b8183960ec5c33 (patch) | |
tree | d3136c22e3e805cfc0efe78412cce905a17e0c8d /lib/windows-recmutex.c | |
parent | 591cbf5878b7d4105b275585b9db1324c9dfce56 (diff) | |
parent | af151c593704a40e10efb28d1e3dd59a23a661f3 (diff) |
Merge branch 'release/debian/1.0-1'debian/1.0-1
Diffstat (limited to 'lib/windows-recmutex.c')
-rw-r--r-- | lib/windows-recmutex.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/lib/windows-recmutex.c b/lib/windows-recmutex.c new file mode 100644 index 0000000..d8087ac --- /dev/null +++ b/lib/windows-recmutex.c @@ -0,0 +1,127 @@ +/* Plain recursive mutexes (native Windows implementation). + Copyright (C) 2005-2022 Free Software Foundation, Inc. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file 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 Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Written by Bruno Haible <bruno@clisp.org>, 2005. + Based on GCC's gthr-win32.h. */ + +#include <config.h> + +/* Specification. */ +#include "windows-recmutex.h" + +#include <errno.h> + +void +glwthread_recmutex_init (glwthread_recmutex_t *mutex) +{ + mutex->owner = 0; + mutex->depth = 0; + InitializeCriticalSection (&mutex->lock); + mutex->guard.done = 1; +} + +int +glwthread_recmutex_lock (glwthread_recmutex_t *mutex) +{ + if (!mutex->guard.done) + { + if (InterlockedIncrement (&mutex->guard.started) == 0) + /* This thread is the first one to need this mutex. Initialize it. */ + glwthread_recmutex_init (mutex); + 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_recmutex_trylock (glwthread_recmutex_t *mutex) +{ + if (!mutex->guard.done) + { + if (InterlockedIncrement (&mutex->guard.started) == 0) + /* This thread is the first one to need this mutex. Initialize it. */ + glwthread_recmutex_init (mutex); + 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_recmutex_unlock (glwthread_recmutex_t *mutex) +{ + if (mutex->owner != GetCurrentThreadId ()) + return EPERM; + if (mutex->depth == 0) + return EINVAL; + if (--(mutex->depth) == 0) + { + mutex->owner = 0; + LeaveCriticalSection (&mutex->lock); + } + return 0; +} + +int +glwthread_recmutex_destroy (glwthread_recmutex_t *mutex) +{ + if (mutex->owner != 0) + return EBUSY; + DeleteCriticalSection (&mutex->lock); + mutex->guard.done = 0; + return 0; +} |