sync/posix/condition.hpp

0001 //////////////////////////////////////////////////////////////////////////////
0002 //
0003 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
0004 // Software License, Version 1.0. (See accompanying file
0005 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // See http://www.boost.org/libs/interprocess for documentation.
0008 //
0009 //////////////////////////////////////////////////////////////////////////////
0010
0011 #ifndef BOOST_INTERPROCESS_POSIX_CONDITION_HPP
0012 #define BOOST_INTERPROCESS_POSIX_CONDITION_HPP
0013
0014 #ifndef BOOST_CONFIG_HPP
0015 #  include <boost/config.hpp>
0016 #endif
0017 #
0018 #if defined(BOOST_HAS_PRAGMA_ONCE)
0019 #  pragma once
0020 #endif
0021
0022 #include <boost/interprocess/detail/config_begin.hpp>
0023 #include <boost/interprocess/detail/workaround.hpp>
0024
0025 #include <boost/interprocess/sync/cv_status.hpp>
0026 #include <pthread.h>
0027 #include <errno.h>
0028 #include <boost/interprocess/sync/posix/pthread_helpers.hpp>
0029 #include <boost/interprocess/sync/posix/timepoint_to_timespec.hpp>
0030 #include <boost/interprocess/detail/timed_utils.hpp>
0031 #include <boost/interprocess/sync/posix/mutex.hpp>
0032 #include <boost/assert.hpp>
0033
0034 namespace boost {
0035 namespace interprocess {
0036 namespace ipcdetail {
0037
0038 class posix_condition
0039 {
0040    //Non-copyable
0041    posix_condition(const posix_condition &);
0042    posix_condition &operator=(const posix_condition &);
0043
0044    public:
0045    //!Constructs a posix_condition. On error throws interprocess_exception.
0046    posix_condition();
0047
0048    //!Destroys *this
0049    //!liberating system resources.
0050    ~posix_condition();
0051
0052    //!If there is a thread waiting on *this, change that
0053    //!thread's state to ready. Otherwise there is no effect.
0054    void notify_one();
0055
0056    //!Change the state of all threads waiting on *this to ready.
0057    //!If there are no waiting threads, notify_all() has no effect.
0058    void notify_all();
0059
0060    //!Releases the lock on the posix_mutex object associated with lock, blocks
0061    //!the current thread of execution until readied by a call to
0062    //!this->notify_one() or this->notify_all(), and then reacquires the lock.
0063    template <typename L>
0064    void wait(L& lock)
0065    {
0066       if (!lock)
0067          throw lock_exception();
0068       this->do_wait(*lock.mutex());
0069    }
0070
0071    //!The same as:
0072    //!while (!pred()) wait(lock)
0073    template <typename L, typename Pr>
0074    void wait(L& lock, Pr pred)
0075    {
0076       if (!lock)
0077          throw lock_exception();
0078
0079       while (!pred())
0080          this->do_wait(*lock.mutex());
0081    }
0082
0083    //!Releases the lock on the posix_mutex object associated with lock, blocks
0084    //!the current thread of execution until readied by a call to
0085    //!this->notify_one() or this->notify_all(), or until time abs_time is reached,
0086    //!and then reacquires the lock.
0087    //!Returns: false if time abs_time is reached, otherwise true.
0088    template <typename L, typename TimePoint>
0089    bool timed_wait(L& lock, const TimePoint &abs_time)
0090    {
0091       if (!lock)
0092          throw lock_exception();
0093       //Posix does not support infinity absolute time so handle it here
0094       if(ipcdetail::is_pos_infinity(abs_time)){
0095          this->wait(lock);
0096          return true;
0097       }
0098       return this->do_timed_wait(abs_time, *lock.mutex());
0099    }
0100
0101    //!The same as:   while (!pred()) {
0102    //!                  if (!timed_wait(lock, abs_time)) return pred();
0103    //!               } return true;
0104    template <typename L, typename TimePoint, typename Pr>
0105    bool timed_wait(L& lock, const TimePoint &abs_time, Pr pred)
0106    {
0107       if (!lock)
0108          throw lock_exception();
0109       //Posix does not support infinity absolute time so handle it here
0110       if(ipcdetail::is_pos_infinity(abs_time)){
0111          this->wait(lock, pred);
0112          return true;
0113       }
0114       while (!pred()){
0115          if (!this->do_timed_wait(abs_time, *lock.mutex()))
0116             return pred();
0117       }
0118       return true;
0119    }
0120
0121    //!Same as `timed_wait`, but this function is modeled after the
0122    //!standard library interface.
0123    template <typename L, class TimePoint>
0124    cv_status wait_until(L& lock, const TimePoint &abs_time)
0125    {  return this->timed_wait(lock, abs_time) ? cv_status::no_timeout : cv_status::timeout; }
0126
0127    //!Same as `timed_wait`, but this function is modeled after the
0128    //!standard library interface.
0129    template <typename L, class TimePoint, typename Pr>
0130    bool wait_until(L& lock, const TimePoint &abs_time, Pr pred)
0131    {  return this->timed_wait(lock, abs_time, pred); }
0132
0133    template <typename L, class Duration>
0134    cv_status wait_for(L& lock, const Duration &dur)
0135    {  return this->wait_until(lock, duration_to_ustime(dur)) ? cv_status::no_timeout : cv_status::timeout; }
0136
0137    template <typename L, class Duration, typename Pr>
0138    bool wait_for(L& lock, const Duration &dur, Pr pred)
0139    {  return this->wait_until(lock, duration_to_ustime(dur), pred); }
0140
0141    void do_wait(posix_mutex &mut);
0142
0143    template<class TimePoint>
0144    bool do_timed_wait(const TimePoint &abs_time, posix_mutex &mut);
0145
0146    private:
0147    pthread_cond_t   m_condition;
0148 };
0149
0150 inline posix_condition::posix_condition()
0151 {
0152    int res;
0153    pthread_condattr_t cond_attr;
0154    res = pthread_condattr_init(&cond_attr);
0155    if(res != 0){
0156       throw interprocess_exception("pthread_condattr_init failed");
0157    }
0158    res = pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED);
0159    if(res != 0){
0160       pthread_condattr_destroy(&cond_attr);
0161       throw interprocess_exception(res);
0162    }
0163    res = pthread_cond_init(&m_condition, &cond_attr);
0164    pthread_condattr_destroy(&cond_attr);
0165    if(res != 0){
0166       throw interprocess_exception(res);
0167    }
0168 }
0169
0170 inline posix_condition::~posix_condition()
0171 {
0172     int res = 0;
0173     res = pthread_cond_destroy(&m_condition);
0174     BOOST_ASSERT(res == 0); (void)res;
0175 }
0176
0177 inline void posix_condition::notify_one()
0178 {
0179     int res = 0;
0180     res = pthread_cond_signal(&m_condition);
0181     BOOST_ASSERT(res == 0); (void)res;
0182 }
0183
0184 inline void posix_condition::notify_all()
0185 {
0186     int res = 0;
0187     res = pthread_cond_broadcast(&m_condition);
0188     BOOST_ASSERT(res == 0); (void)res;
0189 }
0190
0191 inline void posix_condition::do_wait(posix_mutex &mut)
0192 {
0193    pthread_mutex_t* pmutex = &mut.m_mut;
0194    int res = 0;
0195    res = pthread_cond_wait(&m_condition, pmutex);
0196    BOOST_ASSERT(res == 0); (void)res;
0197 }
0198
0199 template<class TimePoint>
0200 inline bool posix_condition::do_timed_wait
0201    (const TimePoint &abs_time, posix_mutex &mut)
0202 {
0203    timespec ts = timepoint_to_timespec(abs_time);
0204    pthread_mutex_t* pmutex = &mut.m_mut;
0205    int res = 0;
0206    res = pthread_cond_timedwait(&m_condition, pmutex, &ts);
0207    BOOST_ASSERT(res == 0 || res == ETIMEDOUT);
0208
0209    return res != ETIMEDOUT;
0210 }
0211
0212 }  //namespace ipcdetail
0213 }  //namespace interprocess
0214 }  //namespace boost
0215
0216 #include <boost/interprocess/detail/config_end.hpp>
0217
0218 #endif   //#ifndef BOOST_INTERPROCESS_POSIX_CONDITION_HPP