1 files changed, 220 insertions, 0 deletions
diff --git a/threads.c b/threads.c
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index 00000000..03f19ff9
--- /dev/null
+++ b/threads.c
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+/* threads.c
+ *
+ * This file implements threading support helpers (and maybe the thread object)
+ * for rsyslog.
+ * 
+ * File begun on 2007-12-14 by RGerhards
+ *
+ * Copyright 2007 Rainer Gerhards and Adiscon GmbH.
+ *
+ * This file is part of rsyslog.
+ *
+ * Rsyslog 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Rsyslog is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * A copy of the GPL can be found in the file "COPYING" in this distribution.
+ */
+#include "config.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <pthread.h>
+#include <assert.h>
+
+#include "rsyslog.h"
+#include "syslogd.h"
+#include "linkedlist.h"
+#include "threads.h"
+
+/* linked list of currently-known threads */
+static linkedList_t llThrds;
+
+/* methods */
+
+/* Construct a new thread object
+ */
+static rsRetVal thrdConstruct(thrdInfo_t **ppThis)
+{
+	DEFiRet;
+	thrdInfo_t *pThis;
+
+	assert(ppThis != NULL);
+
+	if((pThis = calloc(1, sizeof(thrdInfo_t))) == NULL)
+		return RS_RET_OUT_OF_MEMORY;
+
+	/* OK, we got the element, now initialize members that should
+	 * not be zero-filled.
+	 */
+	pThis->mutTermOK = (pthread_mutex_t *) malloc (sizeof (pthread_mutex_t));
+	pthread_mutex_init (pThis->mutTermOK, NULL);
+
+	*ppThis = pThis;
+	RETiRet;
+}
+
+
+/* Destructs a thread object. The object must not be linked to the
+ * linked list of threads. Please note that the thread should have been
+ * stopped before. If not, we try to do it.
+ */
+static rsRetVal thrdDestruct(thrdInfo_t *pThis)
+{
+	DEFiRet;
+	assert(pThis != NULL);
+
+	if(pThis->bIsActive == 1) {
+		thrdTerminate(pThis);
+	}
+	free(pThis->mutTermOK);
+	free(pThis);
+
+	RETiRet;
+}
+
+
+/* terminate a thread gracefully.
+ */
+rsRetVal thrdTerminate(thrdInfo_t *pThis)
+{
+	DEFiRet;
+	assert(pThis != NULL);
+	
+	pthread_cancel(pThis->thrdID);
+	pthread_join(pThis->thrdID, NULL); /* wait for cancel to complete */
+	pThis->bIsActive = 0;
+
+	/* call cleanup function, if any */
+	if(pThis->pAfterRun != NULL)
+		pThis->pAfterRun(pThis);
+	
+	RETiRet;
+}
+
+
+/* terminate all known threads gracefully.
+ */
+rsRetVal thrdTerminateAll(void)
+{
+	DEFiRet;
+	llDestroy(&llThrds);
+	RETiRet;
+}
+
+
+/* This is an internal wrapper around the user thread function. Its
+ * purpose is to handle all the necessary housekeeping stuff so that the
+ * user function needs not to be aware of the threading calls. The user
+ * function call has just "normal", non-threading semantics.
+ * rgerhards, 2007-12-17
+ */
+static void* thrdStarter(void *arg)
+{
+	DEFiRet;
+	thrdInfo_t *pThis = (thrdInfo_t*) arg;
+
+	assert(pThis != NULL);
+	assert(pThis->pUsrThrdMain != NULL);
+
+	/* block all signalsi */
+	sigset_t sigSet;
+	sigfillset(&sigSet);
+	pthread_sigmask(SIG_BLOCK, &sigSet, NULL);
+
+	/* setup complete, we are now ready to execute the user code. We will not
+	 * regain control until the user code is finished, in which case we terminate
+	 * the thread.
+	 */
+	iRet = pThis->pUsrThrdMain(pThis);
+
+	dbgprintf("thrdStarter: usrThrdMain 0x%lx returned with iRet %d, exiting now.\n", (unsigned long) pThis->thrdID, iRet);
+	ENDfunc
+	pthread_exit(0);
+}
+
+/* Start a new thread and add it to the list of currently
+ * executing threads. It is added at the end of the list.
+ * rgerhards, 2007-12-14
+ */
+rsRetVal thrdCreate(rsRetVal (*thrdMain)(thrdInfo_t*), rsRetVal(*afterRun)(thrdInfo_t *))
+{
+	DEFiRet;
+	thrdInfo_t *pThis;
+	int i;
+
+	assert(thrdMain != NULL);
+
+	CHKiRet(thrdConstruct(&pThis));
+	pThis->bIsActive = 1;
+	pThis->pUsrThrdMain = thrdMain;
+	pThis->pAfterRun = afterRun;
+	i = pthread_create(&pThis->thrdID, NULL, thrdStarter, pThis);
+	CHKiRet(llAppend(&llThrds, NULL, pThis));
+
+finalize_it:
+	RETiRet;
+}
+
+
+/* initialize the thread-support subsystem
+ * must be called once at the start of the program
+ */
+rsRetVal thrdInit(void)
+{
+	DEFiRet;
+	iRet = llInit(&llThrds, thrdDestruct, NULL, NULL);
+	RETiRet;
+}
+
+
+/* de-initialize the thread subsystem
+ * must be called once at the end of the program
+ */
+rsRetVal thrdExit(void)
+{
+	DEFiRet;
+
+	iRet = llDestroy(&llThrds);
+
+	RETiRet;
+}
+
+
+/* thrdSleep() - a fairly portable way to put a thread to sleep. It 
+ * will wake up when
+ * a) the wake-time is over
+ * b) the thread shall be terminated
+ * Returns RS_RET_OK if all went well, RS_RET_TERMINATE_NOW if the calling
+ * thread shall be terminated and any other state if an error happened.
+ * rgerhards, 2007-12-17
+ */
+rsRetVal
+thrdSleep(thrdInfo_t *pThis, int iSeconds, int iuSeconds)
+{
+	DEFiRet;
+	struct timeval tvSelectTimeout;
+
+	assert(pThis != NULL);
+	tvSelectTimeout.tv_sec = iSeconds;
+	tvSelectTimeout.tv_usec = iuSeconds; /* micro seconds */
+	select(1, NULL, NULL, NULL, &tvSelectTimeout);
+	if(pThis->bShallStop)
+		iRet = RS_RET_TERMINATE_NOW;
+	RETiRet;
+}
+
+
+/*
+ * vi:set ai:
+ */