semspingpong.cpp revision 760e27ea38bd47048a383cdfc6aa78d1a1637363
/* $Id$ */
/** @file
* innotek Portable Runtime - Thread Ping-Pong Construct.
*/
/*
* Copyright (C) 2006-2007 innotek GmbH
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License as published by the Free Software Foundation,
* in version 2 as it comes in the "COPYING" file of the VirtualBox OSE
* distribution. VirtualBox OSE is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY of any kind.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#include <iprt/semaphore.h>
#include <iprt/thread.h>
#include <iprt/asm.h>
#include <iprt/assert.h>
#include <iprt/err.h>
/**
* Validates a pPP handle passed to one of the PP functions.
*
* @returns true if valid, false if invalid.
* @param pPP Pointe to the ping-pong structure.
*/
inline bool rtsemPPValid(PRTPINGPONG pPP)
{
if (!VALID_PTR(pPP))
return false;
RTPINGPONGSPEAKER enmSpeaker = pPP->enmSpeaker;
if ( enmSpeaker != RTPINGPONGSPEAKER_PING
&& enmSpeaker != RTPINGPONGSPEAKER_PONG
&& enmSpeaker != RTPINGPONGSPEAKER_PONG_SIGNALED
&& enmSpeaker != RTPINGPONGSPEAKER_PING_SIGNALED)
return false;
return true;
}
/**
* Init a Ping-Pong construct.
*
* @returns iprt status code.
* @param pPP Pointer to the ping-pong structure which needs initialization.
*/
RTR3DECL(int) RTSemPingPongInit(PRTPINGPONG pPP)
{
/*
* Init the structure.
*/
pPP->enmSpeaker = RTPINGPONGSPEAKER_PING;
int rc = RTSemEventCreate(&pPP->Ping);
if (RT_SUCCESS(rc))
{
rc = RTSemEventCreate(&pPP->Pong);
if (RT_SUCCESS(rc))
return VINF_SUCCESS;
RTSemEventDestroy(pPP->Ping);
}
return rc;
}
/**
* Destroys a Ping-Pong construct.
*
* @returns iprt status code.
* @param pPP Pointer to the ping-pong structure which is to be destroyed.
* (I.e. put into uninitialized state.)
*/
RTR3DECL(int) RTSemPingPongDestroy(PRTPINGPONG pPP)
{
/*
* Validate input
*/
if (!rtsemPPValid(pPP))
{
AssertMsgFailed(("Invalid input %p\n", pPP));
return VERR_INVALID_PARAMETER;
}
/*
* Invalidate the ping pong handle and destroy the event semaphores.
*/
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_UNINITIALIZE);
int rc = RTSemEventDestroy(pPP->Ping);
int rc2 = RTSemEventDestroy(pPP->Pong);
AssertRC(rc);
AssertRC(rc2);
return VINF_SUCCESS;
}
/**
* Signals the pong thread in a ping-pong construct. (I.e. sends ping.)
* This is called by the ping thread.
*
* @returns iprt status code.
* @param pPP Pointer to the ping-pong structure to ping.
*/
RTR3DECL(int) RTSemPing(PRTPINGPONG pPP)
{
/*
* Validate input
*/
if (!rtsemPPValid(pPP))
{
AssertMsgFailed(("Invalid input %p\n", pPP));
return VERR_INVALID_PARAMETER;
}
if (pPP->enmSpeaker != RTPINGPONGSPEAKER_PING)
{
AssertMsgFailed(("Speaking out of turn!\n"));
return VERR_SEM_OUT_OF_TURN;
}
/*
* Signal the other thread.
*/
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PONG_SIGNALED);
int rc = RTSemEventSignal(pPP->Pong);
if (RT_SUCCESS(rc))
return rc;
/* restore the state. */
AssertMsgFailed(("Failed to signal pong sem %x. rc=%d\n", pPP->Pong, rc));
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PING);
return rc;
}
/**
* Signals the ping thread in a ping-pong construct. (I.e. sends pong.)
* This is called by the pong thread.
*
* @returns iprt status code.
* @param pPP Pointer to the ping-pong structure to pong.
*/
RTR3DECL(int) RTSemPong(PRTPINGPONG pPP)
{
/*
* Validate input
*/
if (!rtsemPPValid(pPP))
{
AssertMsgFailed(("Invalid input %p\n", pPP));
return VERR_INVALID_PARAMETER;
}
if (pPP->enmSpeaker != RTPINGPONGSPEAKER_PONG)
{
AssertMsgFailed(("Speaking out of turn!\n"));
return VERR_SEM_OUT_OF_TURN;
}
/*
* Signal the other thread.
*/
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PING_SIGNALED);
int rc = RTSemEventSignal(pPP->Ping);
if (RT_SUCCESS(rc))
return rc;
/* restore the state. */
AssertMsgFailed(("Failed to signal ping sem %x. rc=%d\n", pPP->Ping, rc));
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PONG);
return rc;
}
/**
* Wait function for the ping thread.
*
* @returns iprt status code.
* Will not return VERR_INTERRUPTED.
* @param pPP Pointer to the ping-pong structure to wait on.
* @param cMillies Number of milliseconds to wait.
*/
RTR3DECL(int) RTSemPingWait(PRTPINGPONG pPP, unsigned cMillies)
{
/*
* Validate input
*/
if (!rtsemPPValid(pPP))
{
AssertMsgFailed(("Invalid input %p\n", pPP));
return VERR_INVALID_PARAMETER;
}
if ( pPP->enmSpeaker != RTPINGPONGSPEAKER_PONG
&& pPP->enmSpeaker != RTPINGPONGSPEAKER_PONG_SIGNALED
&& pPP->enmSpeaker != RTPINGPONGSPEAKER_PING_SIGNALED)
{
AssertMsgFailed(("Listening out of turn! enmSpeaker=%d\n", pPP->enmSpeaker));
return VERR_SEM_OUT_OF_TURN;
}
/*
* Wait.
*/
int rc = RTSemEventWait(pPP->Ping, cMillies);
if (RT_SUCCESS(rc))
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PING);
Assert(rc != VERR_INTERRUPTED);
return rc;
}
/**
* Wait function for the pong thread.
*
* @returns iprt status code.
* Will not return VERR_INTERRUPTED.
* @param pPP Pointer to the ping-pong structure to wait on.
* @param cMillies Number of milliseconds to wait.
*/
RTR3DECL(int) RTSemPongWait(PRTPINGPONG pPP, unsigned cMillies)
{
/*
* Validate input
*/
if (!rtsemPPValid(pPP))
{
AssertMsgFailed(("Invalid input %p\n", pPP));
return VERR_INVALID_PARAMETER;
}
if ( pPP->enmSpeaker != RTPINGPONGSPEAKER_PING
&& pPP->enmSpeaker != RTPINGPONGSPEAKER_PING_SIGNALED
&& pPP->enmSpeaker != RTPINGPONGSPEAKER_PONG_SIGNALED)
{
AssertMsgFailed(("Listening out of turn! enmSpeaker=%d\n", pPP->enmSpeaker));
return VERR_SEM_OUT_OF_TURN;
}
/*
* Wait.
*/
int rc = RTSemEventWait(pPP->Pong, cMillies);
if (RT_SUCCESS(rc))
ASMAtomicXchgSize(&pPP->enmSpeaker, RTPINGPONGSPEAKER_PONG);
Assert(rc != VERR_INTERRUPTED);
return rc;
}