diff options
Diffstat (limited to 'boost/interprocess/sync/shm/named_condition.hpp')
| -rw-r--r-- | boost/interprocess/sync/shm/named_condition.hpp | 47 |
1 files changed, 25 insertions, 22 deletions
diff --git a/boost/interprocess/sync/shm/named_condition.hpp b/boost/interprocess/sync/shm/named_condition.hpp index 0d67c25757..9d7cd77e11 100644 --- a/boost/interprocess/sync/shm/named_condition.hpp +++ b/boost/interprocess/sync/shm/named_condition.hpp @@ -28,7 +28,7 @@ #include <boost/interprocess/sync/shm/named_creation_functor.hpp> #include <boost/interprocess/sync/named_mutex.hpp> #include <boost/interprocess/permissions.hpp> -#if defined BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES +#if defined (BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) #include <boost/interprocess/sync/interprocess_mutex.hpp> #include <boost/interprocess/sync/scoped_lock.hpp> #endif @@ -42,7 +42,7 @@ namespace interprocess { namespace ipcdetail { /// @cond -namespace ipcdetail{ class interprocess_tester; } +class interprocess_tester; /// @endcond //! A global condition variable that can be created by name. @@ -61,7 +61,7 @@ class shm_named_condition //!If the condition can't be created throws interprocess_exception shm_named_condition(create_only_t create_only, const char *name, const permissions &perm = permissions()); - //!Opens or creates a global condition with a name. + //!Opens or creates a global condition with a name. //!If the condition is created, this call is equivalent to //!shm_named_condition(create_only_t, ... ) //!If the condition is already created, this call is equivalent @@ -82,7 +82,7 @@ class shm_named_condition //!use remove(). ~shm_named_condition(); - //!If there is a thread waiting on *this, change that + //!If there is a thread waiting on *this, change that //!thread's state to ready. Otherwise there is no effect.*/ void notify_one(); @@ -90,8 +90,8 @@ class shm_named_condition //!If there are no waiting threads, notify_all() has no effect. void notify_all(); - //!Releases the lock on the named_mutex object associated with lock, blocks - //!the current thread of execution until readied by a call to + //!Releases the lock on the named_mutex object associated with lock, blocks + //!the current thread of execution until readied by a call to //!this->notify_one() or this->notify_all(), and then reacquires the lock. template <typename L> void wait(L& lock); @@ -101,16 +101,16 @@ class shm_named_condition template <typename L, typename Pr> void wait(L& lock, Pr pred); - //!Releases the lock on the named_mutex object associated with lock, blocks - //!the current thread of execution until readied by a call to - //!this->notify_one() or this->notify_all(), or until time abs_time is reached, + //!Releases the lock on the named_mutex object associated with lock, blocks + //!the current thread of execution until readied by a call to + //!this->notify_one() or this->notify_all(), or until time abs_time is reached, //!and then reacquires the lock. //!Returns: false if time abs_time is reached, otherwise true. template <typename L> bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time); - //!The same as: while (!pred()) { - //! if (!timed_wait(lock, abs_time)) return pred(); + //!The same as: while (!pred()) { + //! if (!timed_wait(lock, abs_time)) return pred(); //! } return true; template <typename L, typename Pr> bool timed_wait(L& lock, const boost::posix_time::ptime &abs_time, Pr pred); @@ -147,6 +147,9 @@ class shm_named_condition void unlock() { l_.lock(); } }; + //If named mutex uses POSIX semaphores, then the shm based condition variable + //must use it's internal lock to wait, as sem_t does not store a pthread_mutex_t + //instance needed by pthread_mutex_cond_t #if defined (BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) interprocess_mutex *mutex() const { return &static_cast<condition_holder*>(m_shmem.get_user_address())->mutex_; } @@ -156,7 +159,7 @@ class shm_named_condition { //shm_named_condition only works with named_mutex BOOST_STATIC_ASSERT((is_convertible<typename Lock::mutex_type&, named_mutex&>::value == true)); - + //lock internal before unlocking external to avoid race with a notifier scoped_lock<interprocess_mutex> internal_lock(*this->mutex()); lock_inverter<Lock> inverted_lock(lock); @@ -173,18 +176,18 @@ class shm_named_condition { //shm_named_condition only works with named_mutex BOOST_STATIC_ASSERT((is_convertible<typename Lock::mutex_type&, named_mutex&>::value == true)); - //lock internal before unlocking external to avoid race with a notifier - scoped_lock<interprocess_mutex> internal_lock(*this->mutex(), abs_time); + //lock internal before unlocking external to avoid race with a notifier + scoped_lock<interprocess_mutex> internal_lock(*this->mutex(), abs_time); if(!internal_lock) return false; - lock_inverter<Lock> inverted_lock(lock); - scoped_lock<lock_inverter<Lock> > external_unlock(inverted_lock); + lock_inverter<Lock> inverted_lock(lock); + scoped_lock<lock_inverter<Lock> > external_unlock(inverted_lock); - //unlock internal first to avoid deadlock with near simultaneous waits - scoped_lock<interprocess_mutex> internal_unlock; - internal_lock.swap(internal_unlock); - return this->condition()->timed_wait(internal_unlock, abs_time); + //unlock internal first to avoid deadlock with near simultaneous waits + scoped_lock<interprocess_mutex> internal_unlock; + internal_lock.swap(internal_unlock); + return this->condition()->timed_wait(internal_unlock, abs_time); } - #else + #else //defined (BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) template<class Lock> class lock_wrapper { @@ -210,7 +213,7 @@ class shm_named_condition private: Lock &l_; }; - #endif + #endif //defined (BOOST_INTERPROCESS_NAMED_MUTEX_USES_POSIX_SEMAPHORES) friend class boost::interprocess::ipcdetail::interprocess_tester; void dont_close_on_destruction(); |