/* $Id: semspingpong.cpp 2981 2007-06-01 16:01:28Z vboxsync $ */ /** @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. * * If you received this file as part of a commercial VirtualBox * distribution, then only the terms of your commercial VirtualBox * license agreement apply instead of the previous paragraph. */ /******************************************************************************* * Header Files * *******************************************************************************/ #include #include #include #include #include /** * 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; }