moved queue code to its own module (finally)

6 files changed, 202 insertions, 108 deletions

diff --git a/Makefile.am b/Makefile.am
index 4f3ee472..f4e60f30 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,6 +21,8 @@ rsyslogd_SOURCES = \
 	liblogging-stub.h \
 	threads.c \
 	threads.h \
+	queue.c \
+	queue.h \
 	sync.c \
 	sync.h \
 	net.c \
diff --git a/queue.c b/queue.c
new file mode 100644
index 00000000..95eb8907
--- /dev/null
+++ b/queue.c
@@ -0,0 +1,128 @@
+/* queue.c
+ *
+ * This file implements the queue object and its several queueing methods.
+ * 
+ * File begun on 2008-01-03 by RGerhards
+ *
+ * Copyright 2008 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 <assert.h>
+#include <pthread.h>
+
+#include "rsyslog.h"
+#include "queue.h"
+
+/* static data */
+int iMainMsgQueueSize;
+msgQueue *pMsgQueue = NULL;
+
+/* methods */
+
+/* queue functions (may be migrated to some other file...)
+ */
+
+
+msgQueue *queueInit (void)
+{
+	msgQueue *q;
+
+	q = (msgQueue *)malloc(sizeof(msgQueue));
+	if (q == NULL) return (NULL);
+	if((q->pbuf = malloc(sizeof(void *) * iMainMsgQueueSize)) == NULL) {
+		free(q);
+		return NULL;
+	}
+
+	q->empty = 1;
+	q->full = 0;
+	q->head = 0;
+	q->tail = 0;
+	q->mut = (pthread_mutex_t *) malloc (sizeof (pthread_mutex_t));
+	pthread_mutex_init (q->mut, NULL);
+	q->notFull = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
+	pthread_cond_init (q->notFull, NULL);
+	q->notEmpty = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
+	pthread_cond_init (q->notEmpty, NULL);
+	
+	return (q);
+}
+
+void queueDelete (msgQueue *q)
+{
+	pthread_mutex_destroy (q->mut);
+	free (q->mut);
+	pthread_cond_destroy (q->notFull);
+	free (q->notFull);
+	pthread_cond_destroy (q->notEmpty);
+	free (q->notEmpty);
+	free(q->pbuf);
+	free (q);
+}
+
+
+/* In queueAdd() and queueDel() we have a potential race condition. If a message
+ * is dequeued and at the same time a message is enqueued and the queue is either
+ * full or empty, the full (or empty) indicator may be invalidly updated. HOWEVER,
+ * this does not cause any real problems. No queue pointers can be wrong. And even
+ * if one of the flags is set invalidly, that does not pose a real problem. If
+ * "full" is invalidly set, at mose one message might be lost, if we are already in
+ * a timeout situation (this is quite acceptable). And if "empty" is accidently set,
+ * the receiver will not continue the inner loop, but break out of the outer. So no
+ * harm is done at all. For this reason, I do not yet use a mutex to guard the two
+ * flags - there would be a notable performance hit with, IMHO, no gain in stability
+ * or functionality. But anyhow, now it's documented...
+ * rgerhards, 2007-09-20
+ * NOTE: this comment does not really apply - the callers handle the mutex, so it
+ * *is* guarded.
+ */
+void queueAdd (msgQueue *q, void* in)
+{
+	q->pbuf[q->tail] = in;
+	q->tail++;
+	if (q->tail == iMainMsgQueueSize)
+		q->tail = 0;
+	if (q->tail == q->head)
+		q->full = 1;
+	q->empty = 0;
+
+	return;
+}
+
+void queueDel(msgQueue *q, void **out)
+{
+	*out = (void*) q->pbuf[q->head];
+
+	q->head++;
+	if (q->head == iMainMsgQueueSize)
+		q->head = 0;
+	if (q->head == q->tail)
+		q->empty = 1;
+	q->full = 0;
+
+	return;
+}
+
+/*
+ * vi:set ai:
+ */
diff --git a/queue.h b/queue.h
new file mode 100644
index 00000000..dd74faba
--- /dev/null
+++ b/queue.h
@@ -0,0 +1,71 @@
+/* Definition of the queue support module.
+ *
+ * Copyright 2008 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.
+ */
+
+#ifndef QUEUE_H_INCLUDED
+#define QUEUE_H_INCLUDED
+
+
+/* queue types */
+typedef enum {
+	QUEUETYPE_FIXED_ARRAY,	/* a simple queue made out of a fixed (initially malloced) array fast but memoryhog */
+	QUEUETYPE_LINKEDLIST,	/* linked list used as buffer, lower fixed memory overhead but slower */
+} queueTypes_t;
+
+/* the queue object */
+typedef struct {
+	queueTypes_t	qType;
+	int	iMaxQueSize;	/* how large can the queue grow? */
+	void** pUsr;		/* the queued user data structure */
+	/* synchronization variables */
+	pthread_mutex_t *mut;
+	pthread_cond_t *notFull, *notEmpty;
+	int full, empty;
+	/* end sync variables */
+	union {			/* different data elements based on queue type (qType) */
+		struct {
+			long head, tail;
+		} farray;
+	} tVars;
+} queue_t;
+
+/* this is the first approach to a queue, this time with static
+ * memory.
+ */
+typedef struct {
+	void** pbuf;
+	long head, tail;
+	int full, empty;
+	pthread_mutex_t *mut;
+	pthread_cond_t *notFull, *notEmpty;
+} msgQueue;
+
+/* prototypes */
+msgQueue *queueInit (void);
+void queueDelete (msgQueue *q);
+void queueAdd (msgQueue *q, void* in);
+void queueDel (msgQueue *q, void **out);
+
+/* go-away's */
+extern int iMainMsgQueueSize;
+extern msgQueue *pMsgQueue;
+
+#endif /* #ifndef QUEUE_H_INCLUDED */
diff --git a/syslogd.c b/syslogd.c
index e2efa1bc..e1b0735a 100644
--- a/syslogd.c
+++ b/syslogd.c
@@ -208,6 +208,7 @@
 #include "omfile.h"
 #include "omdiscard.h"
 #include "threads.h"
+#include "queue.h"
 
 /* We define our own set of syslog defintions so that we
  * do not need to rely on (possibly different) implementations.
diff --git a/threads.c b/threads.c
index 38e86195..24cae97f 100644
--- a/threads.c
+++ b/threads.c
@@ -41,10 +41,6 @@
 #include "linkedlist.h"
 #include "threads.h"
 
-/* static data */
-int iMainMsgQueueSize;
-msgQueue *pMsgQueue = NULL;
-
 /* linked list of currently-known threads */
 static linkedList_t llThrds;
 
@@ -263,90 +259,6 @@ thrdSleep(thrdInfo_t *pThis, int iSeconds, int iuSeconds)
 }
 
 
-/* queue functions (may be migrated to some other file...)
- */
-
-
-msgQueue *queueInit (void)
-{
-	msgQueue *q;
-
-	q = (msgQueue *)malloc(sizeof(msgQueue));
-	if (q == NULL) return (NULL);
-	if((q->pbuf = malloc(sizeof(void *) * iMainMsgQueueSize)) == NULL) {
-		free(q);
-		return NULL;
-	}
-
-	q->empty = 1;
-	q->full = 0;
-	q->head = 0;
-	q->tail = 0;
-	q->mut = (pthread_mutex_t *) malloc (sizeof (pthread_mutex_t));
-	pthread_mutex_init (q->mut, NULL);
-	q->notFull = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
-	pthread_cond_init (q->notFull, NULL);
-	q->notEmpty = (pthread_cond_t *) malloc (sizeof (pthread_cond_t));
-	pthread_cond_init (q->notEmpty, NULL);
-	
-	return (q);
-}
-
-void queueDelete (msgQueue *q)
-{
-	pthread_mutex_destroy (q->mut);
-	free (q->mut);
-	pthread_cond_destroy (q->notFull);
-	free (q->notFull);
-	pthread_cond_destroy (q->notEmpty);
-	free (q->notEmpty);
-	free(q->pbuf);
-	free (q);
-}
-
-
-/* In queueAdd() and queueDel() we have a potential race condition. If a message
- * is dequeued and at the same time a message is enqueued and the queue is either
- * full or empty, the full (or empty) indicator may be invalidly updated. HOWEVER,
- * this does not cause any real problems. No queue pointers can be wrong. And even
- * if one of the flags is set invalidly, that does not pose a real problem. If
- * "full" is invalidly set, at mose one message might be lost, if we are already in
- * a timeout situation (this is quite acceptable). And if "empty" is accidently set,
- * the receiver will not continue the inner loop, but break out of the outer. So no
- * harm is done at all. For this reason, I do not yet use a mutex to guard the two
- * flags - there would be a notable performance hit with, IMHO, no gain in stability
- * or functionality. But anyhow, now it's documented...
- * rgerhards, 2007-09-20
- * NOTE: this comment does not really apply - the callers handle the mutex, so it
- * *is* guarded.
- */
-void queueAdd (msgQueue *q, void* in)
-{
-	q->pbuf[q->tail] = in;
-	q->tail++;
-	if (q->tail == iMainMsgQueueSize)
-		q->tail = 0;
-	if (q->tail == q->head)
-		q->full = 1;
-	q->empty = 0;
-
-	return;
-}
-
-void queueDel(msgQueue *q, void **out)
-{
-	*out = (void*) q->pbuf[q->head];
-
-	q->head++;
-	if (q->head == iMainMsgQueueSize)
-		q->head = 0;
-	if (q->head == q->tail)
-		q->empty = 1;
-	q->full = 0;
-
-	return;
-}
-
 /*
  * vi:set ai:
  */
diff --git a/threads.h b/threads.h
index 6bf1e3b1..b0cc9221 100644
--- a/threads.h
+++ b/threads.h
@@ -41,17 +41,6 @@ typedef struct thrdInfo {
 	pthread_t thrdID;
 } thrdInfo_t;
 
-/* this is the first approach to a queue, this time with static
- * memory.
- */
-typedef struct {
-	void** pbuf;
-	long head, tail;
-	int full, empty;
-	pthread_mutex_t *mut;
-	pthread_cond_t *notFull, *notEmpty;
-} msgQueue;
-
 /* prototypes */
 rsRetVal thrdExit(void);
 rsRetVal thrdInit(void);
@@ -59,15 +48,6 @@ rsRetVal thrdTerminate(thrdInfo_t *pThis);
 rsRetVal thrdTerminateAll(void);
 rsRetVal thrdCreate(rsRetVal (*thrdMain)(thrdInfo_t*), eTermSyncType_t eTermSyncType, rsRetVal(*afterRun)(thrdInfo_t *));
 rsRetVal thrdSleep(thrdInfo_t *pThis, int iSeconds, int iuSeconds);
-msgQueue *queueInit (void);
-void queueDelete (msgQueue *q);
-void queueAdd (msgQueue *q, void* in);
-void queueDel (msgQueue *q, void **out);
-
-/* go-away's */
-extern int iMainMsgQueueSize;
-extern msgQueue *pMsgQueue;
-
 
 /* macros (replace inline functions) */
 /*TODO: remove these macros once we now we can live without -- rgerhards, 2007-12-20