+/*
+ * Copyright (c) 2016, JANET(UK)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JANET(UK) nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
#include <talloc.h>
#include <pthread.h>
+#include <time.h>
+#include <errno.h>
#include <tr_mq.h>
+#include <tr_debug.h>
/* Messages */
static int tr_mq_msg_destructor(void *object)
return 0;
}
-TR_MQ_MSG *tr_mq_msg_new(TALLOC_CTX *mem_ctx)
+TR_MQ_MSG *tr_mq_msg_new(TALLOC_CTX *mem_ctx, const char *message, TR_MQ_PRIORITY prio)
{
TR_MQ_MSG *msg=talloc(mem_ctx, TR_MQ_MSG);
if (msg!=NULL) {
msg->next=NULL;
+ msg->prio=prio;
+ msg->message=talloc_strdup(msg, message);
+ if (msg->message==NULL) {
+ talloc_free(msg);
+ return NULL;
+ }
msg->p=NULL;
talloc_set_destructor((void *)msg, tr_mq_msg_destructor);
}
talloc_free(msg);
}
+TR_MQ_PRIORITY tr_mq_msg_get_prio(TR_MQ_MSG *msg)
+{
+ return msg->prio;
+}
+
+const char *tr_mq_msg_get_message(TR_MQ_MSG *msg)
+{
+ return msg->message;
+}
+
+void *tr_mq_msg_get_payload(TR_MQ_MSG *msg)
+{
+ return msg->p;
+}
+
+/* call with a pointer to the payload and a function to free it later */
+void tr_mq_msg_set_payload(TR_MQ_MSG *msg, void *p, void (*p_free)(void *))
+{
+ msg->p=p;
+ msg->p_free=p_free;
+}
+
+
+static TR_MQ_MSG *tr_mq_msg_get_next(TR_MQ_MSG *msg)
+{
+ return msg->next;
+}
+
+static void tr_mq_msg_set_next(TR_MQ_MSG *msg, TR_MQ_MSG *next)
+{
+ msg->next=next;
+}
+
/* Message Queues */
TR_MQ *tr_mq_new(TALLOC_CTX *mem_ctx)
{
TR_MQ *mq=talloc(mem_ctx, TR_MQ);
+ pthread_condattr_t cattr;
+
if (mq!=NULL) {
- pthread_mutex_init(&(mq->lock), 0);
+ pthread_mutex_init(&(mq->mutex), 0);
+ pthread_condattr_init(&cattr);
+
+ pthread_condattr_setclock(&cattr, CLOCK_MONOTONIC); /* use the monotonic clock for timeouts */
+ pthread_cond_init(&(mq->have_msg_cond), &cattr);
+ pthread_condattr_destroy(&cattr);
+
mq->head=NULL;
mq->tail=NULL;
+ mq->last_hi_prio=NULL;
+
+ mq->notify_cb=NULL;
+ mq->notify_cb_arg=NULL;
}
return mq;
}
void tr_mq_free(TR_MQ *mq)
{
if (mq!=NULL) {
- pthread_mutex_lock(&(mq->lock)); /* don't pull this out from under someone */
+ tr_mq_lock(mq); /* don't pull the rug out from under someone */
talloc_free(mq);
}
}
+int tr_mq_lock(TR_MQ *mq)
+{
+ return pthread_mutex_lock(&(mq->mutex));
+}
+
+int tr_mq_unlock(TR_MQ *mq)
+{
+ return pthread_mutex_unlock(&(mq->mutex));
+}
+
+static TR_MQ_MSG *tr_mq_get_head(TR_MQ *mq)
+{
+ return mq->head;
+}
+
+static void tr_mq_set_head(TR_MQ *mq, TR_MQ_MSG *msg)
+{
+ mq->head=msg;
+}
+
+static TR_MQ_MSG *tr_mq_get_tail(TR_MQ *mq)
+{
+ return mq->tail;
+}
+
+static void tr_mq_set_tail(TR_MQ *mq, TR_MQ_MSG *msg)
+{
+ mq->tail=msg;
+}
+
+void tr_mq_set_notify_cb(TR_MQ *mq, TR_MQ_NOTIFY_FN cb, void *arg)
+{
+ mq->notify_cb=cb;
+ mq->notify_cb_arg=arg;
+}
+
+void tr_mq_clear(TR_MQ *mq)
+{
+ TR_MQ_MSG *m=NULL;
+ TR_MQ_MSG *n=NULL;
+
+ tr_mq_lock(mq);
+ m=tr_mq_get_head(mq);
+ while (m!=NULL) {
+ n=tr_mq_msg_get_next(m);
+ tr_mq_msg_free(m);
+ m=n;
+ }
+ tr_mq_set_head(mq, NULL);
+ tr_mq_set_tail(mq, NULL);
+ tr_mq_unlock(mq);
+}
+
+static int tr_mq_empty(TR_MQ *mq)
+{
+ return tr_mq_get_head(mq)==NULL;
+}
+
/* puts msg in mq's talloc context */
-void tr_mq_append(TR_MQ *mq, TR_MQ_MSG *msg)
+static void tr_mq_append(TR_MQ *mq, TR_MQ_MSG *msg)
{
- int was_empty=FALSE;
+ if (tr_mq_get_head(mq)==NULL) {
+ tr_mq_set_head(mq, msg);
+ tr_mq_set_tail(mq, msg);
+ } else {
+ tr_mq_msg_set_next(tr_mq_get_tail(mq), msg); /* add to list */
+ tr_mq_set_tail(mq, msg); /* update tail of list */
+ }
+ talloc_steal(mq, msg);
+}
+
+static void tr_mq_append_high_prio(TR_MQ *mq, TR_MQ_MSG *new)
+{
+ if (tr_mq_get_head(mq)==NULL) {
+ tr_mq_set_head(mq, new);
+ tr_mq_set_tail(mq, new);
+ } else if (mq->last_hi_prio==NULL) {
+ tr_mq_msg_set_next(new, tr_mq_get_head(mq)); /* add to front of list */
+ tr_mq_set_head(mq, new); /* update head of list */
+ } else {
+ tr_mq_msg_set_next(new, tr_mq_msg_get_next(mq->last_hi_prio));
+ tr_mq_msg_set_next(mq->last_hi_prio, new); /* add to end of hi prio msgs */
+ }
+ mq->last_hi_prio=new; /* in any case, this is now the last high priority msg */
+ talloc_steal(mq,new);
+}
+
+#define DEBUG_TR_MQ 0
+#if DEBUG_TR_MQ
+static void tr_mq_print(TR_MQ *mq)
+{
+ TR_MQ_MSG *m=mq->head;
+ int ii=0;
+
+ tr_debug("tr_mq_print: mq contents:");
+ while(m!=NULL) {
+ ii++;
+ tr_debug("tr_mq_print: Entry %02d: %-15s (prio %d)",
+ ii, tr_mq_msg_get_message(m), tr_mq_msg_get_prio(m));
+ m=tr_mq_msg_get_next(m);
+ }
+}
+#endif
+void tr_mq_add(TR_MQ *mq, TR_MQ_MSG *msg)
+{
+ int was_empty=0;
TR_MQ_NOTIFY_FN notify_cb=NULL;
void *notify_cb_arg=NULL;
- pthread_mutex_lock(&(mq->lock));
- if (mq->head==NULL) {
- was_empty=TRUE;
- mq->head=mq->tail=msg;
- } else {
- mq->tail->next=msg; /* add to list */
- mq->tail=msg; /* update tail of list */
+ tr_mq_lock(mq);
+
+ was_empty=tr_mq_empty(mq);
+ switch (tr_mq_msg_get_prio(msg)) {
+ case TR_MQ_PRIO_HIGH:
+ tr_mq_append_high_prio(mq, msg);
+ break;
+ default:
+ tr_mq_append(mq, msg);
+ break;
}
- talloc_steal(mq, msg);
- /* before releasing the lock, get notify_cb data out of mq */
+ /* before releasing the mutex, get notify_cb data out of mq */
notify_cb=mq->notify_cb;
notify_cb_arg=mq->notify_cb_arg;
- pthread_mutex_unlock(&(mq->lock));
+
+#if DEBUG_TR_MQ
+ tr_mq_print(mq);
+#endif
+
+ /* Before releasing the lock, signal any waiting threads that there's now
+ * something in the queue. Used for blocking tr_mq_pop() call. */
+
+ if (was_empty)
+ pthread_cond_broadcast(&(mq->have_msg_cond));
+
+ tr_mq_unlock(mq);
/* see if we need to tell someone we became non-empty */
if (was_empty && (notify_cb!=NULL))
- mq->notify_cb(mq, notify_cb_arg);
+ notify_cb(mq, notify_cb_arg);
+}
+
+/* Compute an absolute time from a desired timeout interval for use with tr_mq_pop().
+ * Fills in *ts and returns 0 on success. */
+int tr_mq_pop_timeout(time_t seconds, struct timespec *ts)
+{
+ if (0!=clock_gettime(CLOCK_MONOTONIC, ts))
+ return -1;
+
+ ts->tv_sec+=seconds;
+ return 0;
}
-/* caller must free msg via tr_mq_msg_free */
-TR_MQ_MSG *tr_mq_pop(TR_MQ *mq)
+/* Retrieves a message from the queue, waiting until absolute
+ * time ts_abort before giving up (using CLOCK_MONOTONIC). If ts_abort
+ * has passed, returns an existing message but will not wait if one is
+ * not already available. If ts_abort is null, no blocking. Not
+ * guaranteed to wait if an error occurs - immediately returns without
+ * a message. Use tr_mq_pop_timeout() to get an absolute time that
+ * is guaranteed compatible with this function.
+ *
+ * Caller should free msg via tr_mq_msg_free when done with it. It stays
+ * in the TR_MQ's context, though, so use talloc_steal() if you want to do
+ * something clever with it. */
+TR_MQ_MSG *tr_mq_pop(TR_MQ *mq, struct timespec *ts_abort)
{
TR_MQ_MSG *popped=NULL;
+ int wait_err=0;
+
+ tr_mq_lock(mq);
+ if ((tr_mq_get_head(mq)==NULL) && (ts_abort!=NULL)) {
+ /* No msgs yet, and blocking was requested */
+ while ((wait_err==0) && (NULL==tr_mq_get_head(mq)))
+ wait_err=pthread_cond_timedwait(&(mq->have_msg_cond),
+ &(mq->mutex),
+ ts_abort);
+
+ if ((wait_err!=0) && (wait_err!=ETIMEDOUT)) {
+ tr_notice("tr_mq_pop: error waiting for message.");
+ return NULL;
+ }
+ /* if it timed out, ok to go ahead and check once more for a message, so no special exit */
+ }
+
+ if (tr_mq_get_head(mq)!=NULL) {
+ popped=tr_mq_get_head(mq);
+ tr_mq_set_head(mq, tr_mq_msg_get_next(popped)); /* popped is the old head */
- pthread_mutex_lock(&(mq->lock));
- if (mq->head!=NULL) {
- popped=mq->head;
- mq->head=mq->head->next;
- if (mq->head==NULL)
- mq->tail=NULL; /* just popped the last element */
+ if (popped==mq->last_hi_prio)
+ mq->last_hi_prio=NULL;
+
+ if (tr_mq_get_head(mq)==NULL)
+ tr_mq_set_tail(mq, NULL); /* just popped the last element */
}
- pthread_mutex_unlock(&(mq->lock));
+ tr_mq_unlock(mq);
if (popped!=NULL)
- popped->next=NULL; /* disconnect */
+ tr_mq_msg_set_next(popped, NULL); /* disconnect from list */
return popped;
}
+
projects / trust_router.git / blobdiff