X-Git-Url: https://gerrit.o-ran-sc.org/r/gitweb?a=blobdiff_plain;f=src%2Frmr%2Fcommon%2Fsrc%2Fring_static.c;h=7170a9d0795caadaa191673891f8f67a699f5ffa;hb=ce1c741c01e8387cb095dac5e36a4d8ad91d006d;hp=37bb4dbcf3600a9fa864e151130c92bc654297ad;hpb=c1f84f8a4a4e2b90ad9ec18aba2b5365d3e51386;p=ric-plt%2Flib%2Frmr.git

diff --git a/src/rmr/common/src/ring_static.c b/src/rmr/common/src/ring_static.c
index 37bb4db..7170a9d 100644
--- a/src/rmr/common/src/ring_static.c
+++ b/src/rmr/common/src/ring_static.c
@@ -75,6 +75,7 @@ static void* uta_mk_ring( int size ) {
 		return NULL;
 	}
 
+	r->flags = 0;
 	r->rgate = NULL;
 	r->wgate = NULL;
 	r->head = r->tail = 0;
@@ -85,12 +86,12 @@ static void* uta_mk_ring( int size ) {
 	}
 
 	r->nelements = size;		// because we always have an empty element when full
-	if( (r->data = (void **) malloc( sizeof( void** ) * (r->nelements + 1) )) == NULL ) {
+	if( (r->data = (void **) malloc( sizeof( void* ) * (r->nelements + 1) )) == NULL ) {
 		free( r );
 		return NULL;
 	}
 
-	memset( r->data, 0, sizeof( void** ) * r->nelements );
+	memset( r->data, 0, sizeof( void* ) * r->nelements );
 	r->pfd = eventfd( 0, EFD_SEMAPHORE | EFD_NONBLOCK );		// in semaphore mode counter is maintained with each insert/extract
 	return (void *) r;
 }
@@ -124,7 +125,7 @@ static int uta_ring_config( void* vr, int options ) {
 		}
 	}
 
-	if( options & RING_RLOCK ) {
+	if( options & (RING_RLOCK | RING_FRLOCK) ) {				// read locking
 		if( r->rgate == NULL ) {		// don't realloc
 			r->rgate = (pthread_mutex_t *) malloc( sizeof( *r->rgate ) );
 			if( r->rgate == NULL ) {
@@ -133,6 +134,9 @@ static int uta_ring_config( void* vr, int options ) {
 	
 			pthread_mutex_init( r->rgate, NULL );
 		}
+		if( options & RING_FRLOCK ) {
+			r->flags |= RING_FL_FLOCK;
+		}
 	}
 
 	return 1;
@@ -148,7 +152,15 @@ static void uta_ring_free( void* vr ) {
 	if( (r = (ring_t*) vr) == NULL ) {
 		return;
 	}
-
+	if( r->data ){
+		free( r->data );
+	}
+	if( r->rgate ){
+		free( r->rgate );
+	}
+	if( r->wgate ){
+		free( r->wgate );
+	}
 	free( r );
 }
 
@@ -166,6 +178,7 @@ static inline void* uta_ring_extract( void* vr ) {
 	ring_t*		r;
 	uint16_t	ti;		// real index in data
 	int64_t	ctr;		// pfd counter
+	void*		data;
 
 	if( !RING_FAST ) {								// compiler should drop the conditional when always false
 		if( (r = (ring_t*) vr) == NULL ) {
@@ -179,9 +192,18 @@ static inline void* uta_ring_extract( void* vr ) {
 		return NULL;
 	}
 
-	if( r->rgate != NULL ) {						// if lock exists we must honour it
-		pthread_mutex_lock( r->rgate );
+	if( r->rgate != NULL ) {							// if lock exists we must honour it
+		if( r->flags & RING_FL_FLOCK ) {				// fast read locking try once and return nil if we cant lock
+			if( pthread_mutex_trylock( r->rgate ) != 0 ) {	// quick fail if not able to get a lock
+				return NULL;
+			}
+		} else {
+			if( pthread_mutex_lock( r->rgate ) != 0 ) {
+				return NULL;
+			}
+		}
 		if( r->tail == r->head ) {					// ensure ring didn't go empty while waiting
+			pthread_mutex_unlock( r->rgate );
 			return NULL;
 		}
 	}
@@ -199,15 +221,23 @@ future -- investigate if it's possible only to set/clear when empty or going to
 	}
 */
 
+	data = r->data[ti];						// secure data and clear before letting go of the lock
+	r->data[ti] = NULL;
+
 	if( r->rgate != NULL ) {							// if locked above...
 		pthread_mutex_unlock( r->rgate );
 	}
-	return r->data[ti];
+
+	return data;
 }
 
+
 /*
 	Insert the pointer at the next open space in the ring.
-	Returns 1 if the inert was ok, and 0 if the ring is full.
+	Returns 1 if the inert was ok, and 0 if there is an error;
+	errno will be set to EXFULL if  the ring is full, if the attempt
+	fails with anyt other error that indicates the inability to obtain
+	a lock on the ring.
 */
 static inline int uta_ring_insert( void* vr, void* new_data ) {
 	ring_t*		r;
@@ -222,16 +252,25 @@ static inline int uta_ring_insert( void* vr, void* new_data ) {
 	}
 
 	if( r->wgate != NULL ) {						// if lock exists we must honour it
-		pthread_mutex_lock( r->wgate );
+		if( pthread_mutex_lock( r->wgate ) != 0 ) {
+			return 0;								// leave mutex reason in place
+		}
 	}
 
 	if( r->head+1 == r->tail || (r->head+1 >= r->nelements && !r->tail) ) {		// ring is full
-		if( r->wgate != NULL ) {					// ensure released if needed
+		if( r->wgate != NULL ) {												// ensure released if needed
 			pthread_mutex_unlock( r->wgate );
 		}
+		errno = EXFULL;
 		return 0;
 	}
 
+	r->data[r->head] = new_data;
+	r->head++;
+	if( r->head >= r->nelements ) {
+		r->head = 0;
+	}
+
 	write( r->pfd, &inc, sizeof( inc ) );
 /*
 future -- investigate if it's possible only to set/clear when empty or going to empty
@@ -239,12 +278,6 @@ future -- investigate if it's possible only to set/clear when empty or going to
 	}
 */
 
-	r->data[r->head] = new_data;
-	r->head++;
-	if( r->head >= r->nelements ) {
-		r->head = 0;
-	}
-
 	if( r->wgate != NULL ) {						// if lock exists we must unlock before going
 		pthread_mutex_unlock( r->wgate );
 	}