common: init rbuf memory, assign hd/tl pos in range

Signed-off-by: Arlin Davis <arlin.r.davis@intel.com>

diff --git a/dapl/common/dapl_ring_buffer_util.c b/dapl/common/dapl_ring_buffer_util.c
index 53e6426e9bfbf7ef14849c9b958be04d69e0c2e9..f2fdd567efd4fba3851e8e184a24db3a033d454a 100644 (file)
--- a/dapl/common/dapl_ring_buffer_util.c
+++ b/dapl/common/dapl_ring_buffer_util.c
@@ -73,6 +73,7 @@ DAT_RETURN dapls_rbuf_alloc(INOUT DAPL_RING_BUFFER * rbuf, IN DAT_COUNT size)
        }
 
        rbuf->base = (void *)dapl_os_alloc(rsize * sizeof(void *));
+       dapl_os_memzero (rbuf->base, rsize * sizeof(void *));
        if (rbuf->base != NULL) {
                rbuf->lim = rsize - 1;
                dapl_os_atomic_set(&rbuf->head, 0);
@@ -193,19 +194,18 @@ DAT_RETURN dapls_rbuf_add(IN DAPL_RING_BUFFER * rbuf, IN void *entry)
        int pos;
        int val;
 
-       while (((dapl_os_atomic_read(&rbuf->head) + 1) & rbuf->lim) !=
-              (dapl_os_atomic_read(&rbuf->tail) & rbuf->lim)) {
+       while ((dapl_os_atomic_read(&rbuf->head) + 1) !=
+               dapl_os_atomic_read(&rbuf->tail)) {
                pos = dapl_os_atomic_read(&rbuf->head);
-               val = dapl_os_atomic_assign(&rbuf->head, pos, pos + 1);
+               val = dapl_os_atomic_assign(&rbuf->head, pos, ((pos + 1) & rbuf->lim));
                if (val == pos) {
                        pos = (pos + 1) & rbuf->lim;    /* verify in range */
-                       rbuf->base[pos] = entry;        /* FIXME: there a race condition between this line and the line in dapls_rbuf_remove */
+                       rbuf->base[pos] = entry;
                        return DAT_SUCCESS;
                }
        }
 
        return DAT_ERROR(DAT_INSUFFICIENT_RESOURCES, DAT_RESOURCE_MEMORY);
-
 }
 
 /*
@@ -222,7 +222,6 @@ DAT_RETURN dapls_rbuf_add(IN DAPL_RING_BUFFER * rbuf, IN void *entry)
  * Returns:
  *     DAT_SUCCESS
  *     DAT_QUEUE_EMPTY
-   
  */
 void *dapls_rbuf_remove(IN DAPL_RING_BUFFER * rbuf)
 {
@@ -232,16 +231,14 @@ void *dapls_rbuf_remove(IN DAPL_RING_BUFFER * rbuf)
        while (dapl_os_atomic_read(&rbuf->head) !=
               dapl_os_atomic_read(&rbuf->tail)) {
                pos = dapl_os_atomic_read(&rbuf->tail);
-               val = dapl_os_atomic_assign(&rbuf->tail, pos, pos + 1);
+               val = dapl_os_atomic_assign(&rbuf->tail, pos, ((pos + 1) & rbuf->lim));
                if (val == pos) {
                        pos = (pos + 1) & rbuf->lim;    /* verify in range */
-
-                       return (rbuf->base[pos]);       /* FIXME: there a race condition between this line and the line in dapls_rbuf_add */
+                       return (rbuf->base[pos]);
                }
        }
 
        return NULL;
-
 }
 
 /*

diff --git a/dapl/include/dapl.h b/dapl/include/dapl.h
index 09b7a987761f2f130a017048fc1aee3ea4b1476c..210f1b3cba2bd2d1464e537c4b928fd9a7b649f7 100755 (executable)
--- a/dapl/include/dapl.h
+++ b/dapl/include/dapl.h
@@ -365,7 +365,6 @@ struct dapl_evd
     DAT_EVENT          *events;
     DAPL_RING_BUFFER   free_event_queue;
     DAPL_RING_BUFFER   pending_event_queue;
-    DAPL_OS_LOCK       pending_event_queue_lock; /* temporary workaround for the ring buffer race condition */
 
     /* CQ Completions are not placed into 'deferred_events'
      ** rather they are simply left on the Completion Queue