source: Sophya/trunk/SophyaExt/JThreadsC++/JTCSrc/Monitor.cpp@ 1016

// **********************************************************************
//
// Copyright (c) 2000
// Object Oriented Concepts, Inc.
// Billerica, MA, USA
//
// All Rights Reserved
//
// **********************************************************************

#include <JTC/Types.h>
#include <JTC/Syscall.h>
#include <JTC/Mutex.h>
#include <JTC/Event.h>
#include <JTC/Cond.h>
#include <JTC/Monitor.h>
#include <JTC/Exception.h>
#include <JTC/Handle.h>
#include <JTC/HandleI.h>
#include <JTC/Thread.h>
#include <JTC/ThreadGroup.h>
#include <JTC/Runnable.h>
#include <JTC/Sync.h>

#if defined(HAVE_STRSTREAM)
#   include <strstream>
#else
#   if defined(HAVE_STRSTREA_H)
#       include <strstrea.h>
#   else
#       include <strstream.h>
#   endif
#endif

#ifdef HAVE_STD_IOSTREAM
using namespace std;
#endif

#include <stdlib.h>

//
// Inlining the methods causes problems with CC 7.1 under SGI
//
#if defined(__sgi)
JTCSynchronized::JTCSynchronized(const JTCMonitor& mon)
    : mon_(&mon), lockType_(LOCKED_MONITOR)
{
    mon_ -> lock(false);
}

JTCSynchronized::JTCSynchronized(const JTCMonitor& mon, bool internal)
    : mon_(&mon), lockType_(LOCKED_MONITOR)
{
    mon_ -> lock(internal);
}

JTCSynchronized::JTCSynchronized(const JTCMutex& m)
    : mut_(&m), lockType_(LOCKED_MUTEX)
{
    mut_ -> lock();
}

JTCSynchronized::JTCSynchronized(const JTCRecursiveMutex& m)
    : nrmut_(&m), lockType_(LOCKED_RECURSIVE_MUTEX)
{
    nrmut_ -> lock();
}

JTCSynchronized::~JTCSynchronized()
{
    switch(lockType_)
    {
    case LOCKED_MONITOR:
        mon_ -> unlock();
        break;
    case LOCKED_MUTEX:
        mut_ -> unlock();
        break;
    case LOCKED_RECURSIVE_MUTEX:
        nrmut_ -> unlock();
        break;
    }
}

#endif

// ----------------------------------------------------------------------
// JTCMonitor private member implementation
// ----------------------------------------------------------------------

//
// Verify that the mutex is locked by the calling thread. If the mutex
// is not locked by the calling thread then throw
// JTCIllegalMonitorStateException.
//
void
JTCMonitor::validateMutexOwner(const char* caller) const
{
    if(monMutex_._JTC_getId() != JTCThreadId::self())
    {
        char buf[1024];
        ostrstream os(buf, 1024);
        os << "JTCMonitor::"
           << caller
           << " Thread: "
           << JTCThreadId::self()
           << " doesn't own mutex.  Owner: "
           << monMutex_._JTC_getId() << ends;
        throw JTCIllegalMonitorStateException(buf);
    }
}

//
// Lock the monitors mutex. If internal is set then do not check the
// running status of the current thread.
//
void
JTCMonitor::lock(bool internal) const
{
#ifdef HAVE_JTC_STOP
    if (!internal)
    {
        JTCThread::_JTC_checkRunningStatus();
    }
    ((JTCMonitor*)this) -> internalLock_ = internal;
#endif
    monMutex_.lock();
}

//
// Unlock the monitors mutex. If this was a lock placed by an internal
// method of the JTC library then do not check the current threads
// running status.
//
void
JTCMonitor::unlock() const
{
#ifdef HAVE_JTC_STOP
    bool internalLock = internalLock_;
    
    monMutex_.unlock();
    
    if (!internalLock)
    {
        JTCThread::_JTC_checkRunningStatus();
    }
#else
    
    monMutex_.unlock();
    
#endif
}

// ----------------------------------------------------------------------
// JTCMonitor constructor and destructor
// ----------------------------------------------------------------------

JTCMonitor::JTCMonitor()
    : monCond_(monMutex_)
#ifdef HAVE_JTC_STOP
    , internalLock_(false)
#endif
{
}

JTCMonitor::~JTCMonitor()
{
}

// ----------------------------------------------------------------------
// JTCMonitor public member implementation
// ----------------------------------------------------------------------

//
// Wait for the monitor to be signalled.
//
void
JTCMonitor::wait()
{
#ifdef HAVE_JTC_STOP
    //
    // Check the threads running status.
    //
    JTCThread::_JTC_checkRunningStatus();

    //
    // Verify that the monitor is locked by the calling thread.
    //
    validateMutexOwner("wait");

    //
    // Tell the current thread that it is waiting in a monitor.
    //
    JTCThread::_JTC_setMonitor(this);

    try
    {
        monCond_.wait();
    }
    catch(...)
    {
        //
        // The current thread is no longer in a monitor. Check the
        // running status.
        //
        JTCThread::_JTC_setMonitor(0);
        JTCThread::_JTC_checkRunningStatus();
        throw;
    }

    //
    // The current thread is no longer in a monitor. Check the running
    // status.
    //
    JTCThread::_JTC_setMonitor(0);
    JTCThread::_JTC_checkRunningStatus();
#else
    
    //
    // Verify that the monitor is locked by the calling thread.
    //
    validateMutexOwner("wait(long)");

    monCond_.wait();
    
#endif
}

//
// Wait to be signalled for timeout milliseconds.
//
void
JTCMonitor::wait(long timeout)
{
#ifdef HAVE_JTC_STOP
    //
    // Check the threads running status.
    //
    JTCThread::_JTC_checkRunningStatus();

    //
    // Verify that the monitor is locked by the calling thread.
    //
    validateMutexOwner("wait(long)");

    //
    // Tell the current thread that it is waiting in a monitor.
    //
    JTCThread::_JTC_setMonitor(this);

    try
    {
        monCond_.wait(timeout);
    }
    catch(...)
    {
        //
        // The current thread is no longer in a monitor. Check the
        // running status.
        //
        JTCThread::_JTC_setMonitor(0);
        JTCThread::_JTC_checkRunningStatus();
        throw;
    }

    //
    // The current thread is no longer in a monitor. Check the running
    // status.
    //
    //
    JTCThread::_JTC_setMonitor(0);
    JTCThread::_JTC_checkRunningStatus();
#else

    //
    // Verify that the monitor is locked by the calling thread.
    //
    validateMutexOwner("wait(long)");

    monCond_.wait(timeout);

#endif
}

//
// Wake one waiting thread.
//
void
JTCMonitor::notify()
{
    //
    // Ensure that the monitors mutex is locked by the calling thread.
    //
    validateMutexOwner("notify");
    monCond_.signal();
}

//
// Wake all waiting threads.
//
void
JTCMonitor::notifyAll()
{
    //
    // Ensure that the monitors mutex is locked by the calling thread.
    //
    validateMutexOwner("notifyAll");
    monCond_.broadcast();
}