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authorFlorin Coras <fcoras@cisco.com>2018-08-01 07:53:18 -0700
committerDamjan Marion <dmarion@me.com>2018-08-03 09:11:41 +0000
commitc470e22f12a68f06990f57f12f551fee50b6bb0d (patch)
tree9215cfda7e70ffd2f6789b638b895ea3a7d3d7a3 /src/svm/queue.c
parentc64ba6dc6ab9e3b06feac1a86c2f59d7052609ce (diff)
svm: add support for eventfd signaling to queue
Support the use of eventfds to signal queue updates between consumer and producer pairs. Change-Id: Idb6133be2b731fff78ed520daf9d2e0399642aab Signed-off-by: Florin Coras <fcoras@cisco.com>
Diffstat (limited to 'src/svm/queue.c')
-rw-r--r--src/svm/queue.c96
1 files changed, 54 insertions, 42 deletions
diff --git a/src/svm/queue.c b/src/svm/queue.c
index 8e18f5832e3..0fa1fe9b230 100644
--- a/src/svm/queue.c
+++ b/src/svm/queue.c
@@ -27,42 +27,21 @@
#include <vppinfra/cache.h>
#include <svm/queue.h>
#include <vppinfra/time.h>
-#include <signal.h>
-/*
- * svm_queue_init
- *
- * nels = number of elements on the queue
- * elsize = element size, presumably 4 and cacheline-size will
- * be popular choices.
- * pid = consumer pid
- *
- * The idea is to call this function in the queue consumer,
- * and e-mail the queue pointer to the producer(s).
- *
- * The vpp process / main thread allocates one of these
- * at startup; its main input queue. The vpp main input queue
- * has a pointer to it in the shared memory segment header.
- *
- * You probably want to be on an svm data heap before calling this
- * function.
- */
svm_queue_t *
-svm_queue_init (int nels,
- int elsize, int consumer_pid, int signal_when_queue_non_empty)
+svm_queue_init (void *base, int nels, int elsize)
{
svm_queue_t *q;
pthread_mutexattr_t attr;
pthread_condattr_t cattr;
- q = clib_mem_alloc_aligned (sizeof (svm_queue_t)
- + nels * elsize, CLIB_CACHE_LINE_BYTES);
+ q = (svm_queue_t *) base;
memset (q, 0, sizeof (*q));
q->elsize = elsize;
q->maxsize = nels;
- q->consumer_pid = consumer_pid;
- q->signal_when_queue_non_empty = signal_when_queue_non_empty;
+ q->producer_evtfd = -1;
+ q->consumer_evtfd = -1;
memset (&attr, 0, sizeof (attr));
memset (&cattr, 0, sizeof (cattr));
@@ -88,6 +67,20 @@ svm_queue_init (int nels,
return (q);
}
+svm_queue_t *
+svm_queue_alloc_and_init (int nels, int elsize, int consumer_pid)
+{
+ svm_queue_t *q;
+
+ q = clib_mem_alloc_aligned (sizeof (svm_queue_t)
+ + nels * elsize, CLIB_CACHE_LINE_BYTES);
+ memset (q, 0, sizeof (*q));
+ q = svm_queue_init (q, nels, elsize);
+ q->consumer_pid = consumer_pid;
+
+ return q;
+}
+
/*
* svm_queue_free
*/
@@ -117,6 +110,23 @@ svm_queue_is_full (svm_queue_t * q)
return q->cursize == q->maxsize;
}
+static inline void
+svm_queue_send_signal (svm_queue_t * q, u8 is_prod)
+{
+ if (q->producer_evtfd == -1)
+ {
+ (void) pthread_cond_broadcast (&q->condvar);
+ }
+ else
+ {
+ int __clib_unused rv, fd;
+ u64 data = 1;
+ ASSERT (q->consumer_evtfd != -1);
+ fd = is_prod ? q->producer_evtfd : q->consumer_evtfd;
+ rv = write (fd, &data, sizeof (data));
+ }
+}
+
/*
* svm_queue_add_nolock
*/
@@ -146,11 +156,7 @@ svm_queue_add_nolock (svm_queue_t * q, u8 * elem)
q->tail = 0;
if (need_broadcast)
- {
- (void) pthread_cond_broadcast (&q->condvar);
- if (q->signal_when_queue_non_empty)
- kill (q->consumer_pid, q->signal_when_queue_non_empty);
- }
+ svm_queue_send_signal (q, 1);
return 0;
}
@@ -212,11 +218,8 @@ svm_queue_add (svm_queue_t * q, u8 * elem, int nowait)
q->tail = 0;
if (need_broadcast)
- {
- (void) pthread_cond_broadcast (&q->condvar);
- if (q->signal_when_queue_non_empty)
- kill (q->consumer_pid, q->signal_when_queue_non_empty);
- }
+ svm_queue_send_signal (q, 1);
+
pthread_mutex_unlock (&q->mutex);
return 0;
@@ -276,11 +279,8 @@ svm_queue_add2 (svm_queue_t * q, u8 * elem, u8 * elem2, int nowait)
q->tail = 0;
if (need_broadcast)
- {
- (void) pthread_cond_broadcast (&q->condvar);
- if (q->signal_when_queue_non_empty)
- kill (q->consumer_pid, q->signal_when_queue_non_empty);
- }
+ svm_queue_send_signal (q, 1);
+
pthread_mutex_unlock (&q->mutex);
return 0;
@@ -353,7 +353,7 @@ svm_queue_sub (svm_queue_t * q, u8 * elem, svm_q_conditional_wait_t cond,
q->head = 0;
if (need_broadcast)
- (void) pthread_cond_broadcast (&q->condvar);
+ svm_queue_send_signal (q, 0);
pthread_mutex_unlock (&q->mutex);
@@ -385,7 +385,7 @@ svm_queue_sub2 (svm_queue_t * q, u8 * elem)
pthread_mutex_unlock (&q->mutex);
if (need_broadcast)
- (void) pthread_cond_broadcast (&q->condvar);
+ svm_queue_send_signal (q, 0);
return 0;
}
@@ -410,6 +410,18 @@ svm_queue_sub_raw (svm_queue_t * q, u8 * elem)
return 0;
}
+void
+svm_queue_set_producer_event_fd (svm_queue_t * q, int fd)
+{
+ q->producer_evtfd = fd;
+}
+
+void
+svm_queue_set_consumer_event_fd (svm_queue_t * q, int fd)
+{
+ q->consumer_evtfd = fd;
+}
+
/*
* fd.io coding-style-patch-verification: ON
*