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Diffstat (limited to 'src/common/Mutex.cc')
-rw-r--r-- | src/common/Mutex.cc | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/src/common/Mutex.cc b/src/common/Mutex.cc new file mode 100644 index 00000000..e029adc7 --- /dev/null +++ b/src/common/Mutex.cc @@ -0,0 +1,90 @@ +// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- +// vim: ts=8 sw=2 smarttab +/* + * Ceph - scalable distributed file system + * + * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net> + * + * This is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License version 2.1, as published by the Free Software + * Foundation. See file COPYING. + * + */ + +#include "common/Mutex.h" +#include "common/config.h" +#include "common/Clock.h" +#include "common/valgrind.h" + +Mutex::Mutex(const std::string &n, bool r, bool ld, + bool bt) : + name(n), id(-1), recursive(r), lockdep(ld), backtrace(bt), nlock(0), + locked_by(0) +{ + ANNOTATE_BENIGN_RACE_SIZED(&id, sizeof(id), "Mutex lockdep id"); + ANNOTATE_BENIGN_RACE_SIZED(&nlock, sizeof(nlock), "Mutex nlock"); + ANNOTATE_BENIGN_RACE_SIZED(&locked_by, sizeof(locked_by), "Mutex locked_by"); + if (recursive) { + // Mutexes of type PTHREAD_MUTEX_RECURSIVE do all the same checks as + // mutexes of type PTHREAD_MUTEX_ERRORCHECK. + pthread_mutexattr_t attr; + pthread_mutexattr_init(&attr); + pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); + pthread_mutex_init(&_m,&attr); + pthread_mutexattr_destroy(&attr); + if (lockdep && g_lockdep) + _register(); + } + else if (lockdep) { + // If the mutex type is PTHREAD_MUTEX_ERRORCHECK, then error checking + // shall be provided. If a thread attempts to relock a mutex that it + // has already locked, an error shall be returned. If a thread + // attempts to unlock a mutex that it has not locked or a mutex which + // is unlocked, an error shall be returned. + pthread_mutexattr_t attr; + pthread_mutexattr_init(&attr); + pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK); + pthread_mutex_init(&_m, &attr); + pthread_mutexattr_destroy(&attr); + if (g_lockdep) + _register(); + } + else { + // If the mutex type is PTHREAD_MUTEX_DEFAULT, attempting to recursively + // lock the mutex results in undefined behavior. Attempting to unlock the + // mutex if it was not locked by the calling thread results in undefined + // behavior. Attempting to unlock the mutex if it is not locked results in + // undefined behavior. + pthread_mutex_init(&_m, NULL); + } +} + +Mutex::~Mutex() { + ceph_assert(nlock == 0); + + // helgrind gets confused by condition wakeups leading to mutex destruction + ANNOTATE_BENIGN_RACE_SIZED(&_m, sizeof(_m), "Mutex primitive"); + pthread_mutex_destroy(&_m); + + if (lockdep && g_lockdep) { + lockdep_unregister(id); + } +} + +void Mutex::lock(bool no_lockdep) +{ + if (lockdep && g_lockdep && !no_lockdep && !recursive) _will_lock(); + int r = pthread_mutex_lock(&_m); + ceph_assert(r == 0); + if (lockdep && g_lockdep) _locked(); + _post_lock(); +} + +void Mutex::unlock() +{ + _pre_unlock(); + if (lockdep && g_lockdep) _will_unlock(); + int r = pthread_mutex_unlock(&_m); + ceph_assert(r == 0); +} |