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BUG#: 5314
TITLE: IPC Refactoring

DESCRIPTION: This patch cleans up the IPC related classes. It (1) reorganizes
related classes into their own headers, (2) makes the mutex class recursive to
eliminate recursive lock exclusion logic, (3) reimplements condition variables,
renames dozens of global functions.

//%2006////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
// Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation, The Open Group.
// Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; Symantec Corporation; The Open Group.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Mike Day (mdday@us.ibm.com)
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_Semaphore_h
#define Pegasus_Semaphore_h

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/Linkage.h>
#include <Pegasus/Common/Threads.h>

//==============================================================================
//
// Select sempahore implementation by defining one of these:
//
//    PEGASUS_USE_POSIX_SEMAPHORE
//    PEGASUS_USE_PTHREAD_SEMAPHORE
//    PEGASUS_USE_WINDOWS_SEMAPHORE
//
//==============================================================================

#if defined(PEGASUS_PLATFORM_ZOS_ZSERIES_IBM) || \
    defined(PEGASUS_PLATFORM_AIX_RS_IBMCXX) || \
    defined(PEGASUS_PLATFORM_DARWIN_PPC_GNU) || \
    defined(PEGASUS_PLATFORM_LINUX_GENERIC_GNU) || \
    defined(PEGASUS_PLATFORM_VMS_IA64_DECCXX) || \
    defined(PEGASUS_PLATFORM_VMS_ALPHA_DECCXX)
# define PEGASUS_USE_PTHREAD_SEMAPHORE
#elif defined(PEGASUS_OS_TYPE_WINDOWS)
# define PEGASUS_USE_WINDOWS_SEMAPHORE
#else
# define PEGASUS_USE_POSIX_SEMAPHORE
#endif

#if defined(PEGASUS_USE_POSIX_SEMAPHORE)
# include <semaphore.h>
#endif

PEGASUS_NAMESPACE_BEGIN

//==============================================================================
//
// SemaphoreRep
//
//==============================================================================

#if defined(PEGASUS_USE_PTHREAD_SEMAPHORE)
struct SemaphoreRep
{
    Uint32 waiters;
    pthread_mutex_t mutex;
    pthread_cond_t cond;
    ThreadType owner;
};
#endif /* PEGASUS_USE_PTHREAD_SEMAPHORE */

#if defined(PEGASUS_USE_POSIX_SEMAPHORE)
struct SemaphoreRep
{
    sem_t sem;
    ThreadType owner;
};
#endif /* defined(PEGASUS_USE_POSIX_SEMAPHORE) */

#if defined(PEGASUS_USE_WINDOWS_SEMAPHORE)
struct SemaphoreRep
{
    HANDLE sem;
    ThreadType owner;
};
#endif /* PEGASUS_USE_WINDOWS_SEMAPHORE */

//==============================================================================
//
// Semaphore
//
//==============================================================================

class PEGASUS_COMMON_LINKAGE Semaphore
{
public:

    /** Creates a semaphore and sets its initial value as specified.
        @param initial The initial value for the Semaphore (defaults to 1).
    */
    Semaphore(Uint32 initial = 1);

    /** Destructor.
    */
    ~Semaphore();

    /** Blocks until this Semaphore is in a signalled state.
        @param ignoreInterrupt Indicates whether the wait operation should
        continue (true) or an exception should be thrown (false) when an
        interrupt is received.
        @exception WaitFailed If unable to block on the semaphore.
        @exception WaitInterrupted If the operation is interrupted.
    */
    void wait(Boolean ignoreInterrupt = true);

    /** Checks whether the Semaphore is signalled without waiting.  This method
        returns normally if the Semaphore has a non-zero count.
        @exception WaitFailed If the wait operation does not immediately
        succeed.
    */
    void try_wait();

    /** Waits for the Semaphore to be signalled for a specified time interval.
        This method returns normally if the Semaphore has a non-zero count or
        it is signalled during the specified time interval.
        @param milliseconds The time interval to wait (in milliseconds).
        @exception TimeOut If the wait operation does not succeed within
        the specified time interval.
    */
    void time_wait(Uint32 milliseconds);

    /** Increments the count of the semaphore.
    */
    void signal();

    /** Return the count of the semaphore.
    */
    int count() const;

private:

    Semaphore(const Semaphore& x); // Unimplemented
    Semaphore& operator=(const Semaphore& x); // Unimplemented

    mutable int _count;
    mutable SemaphoreRep _rep;
    friend class Condition;
};

PEGASUS_NAMESPACE_END

#endif /* Pegasus_Semaphore_h */