Add SI95 transport support

[ric-plt/lib/rmr.git] / src / rmr / common / src / ring_static.c

diff --git a/src/rmr/common/src/ring_static.c b/src/rmr/common/src/ring_static.c
index dafc946..93dfdb7 100644 (file)
--- a/src/rmr/common/src/ring_static.c
+++ b/src/rmr/common/src/ring_static.c
@@ -35,9 +35,32 @@
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>
+#include <sys/eventfd.h>
 
 #define RING_FAST 1                    // when set we skip nil pointer checks on the ring pointer
 
+/*
+       This returns the ring's pollable file descriptor. If one does not exist, then
+       it is created.
+*/
+static int uta_ring_getpfd( void* vr ) {
+       ring_t*         r;
+
+       if( !RING_FAST ) {                                                              // compiler should drop the conditional when always false
+               if( (r = (ring_t*) vr) == NULL ) {
+                       return 0;
+               }
+       } else {
+               r = (ring_t*) vr;
+       }
+
+       if( r->pfd < 0 ) {
+               r->pfd = eventfd( 0, EFD_SEMAPHORE | EFD_NONBLOCK );
+       }
+
+       return r->pfd;
+}
+
 /*
        Make a new ring.
 */
@@ -63,6 +86,7 @@ static void* uta_mk_ring( int size ) {
        }
 
        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;
 }
 
@@ -88,6 +112,7 @@ static void uta_ring_free( void* vr ) {
 static inline void* uta_ring_extract( void* vr ) {
        ring_t*         r;
        uint16_t        ti;             // real index in data
+       int64_t ctr;            // pfd counter
 
        if( !RING_FAST ) {                                                              // compiler should drop the conditional when always false
                if( (r = (ring_t*) vr) == NULL ) {
@@ -107,6 +132,12 @@ static inline void* uta_ring_extract( void* vr ) {
                r->tail = 0;
        }
 
+       read( r->pfd, &ctr, sizeof( ctr )  );                           // when not in semaphore, this zeros the counter and value is meaningless
+/*
+future -- investigate if it's possible only to set/clear when empty or going to empty
+       if( r->tail == r->head ) {                                                              // if this emptied the ring, turn off ready
+       }
+*/
        return r->data[ti];
 }
 
@@ -116,6 +147,7 @@ static inline void* uta_ring_extract( void* vr ) {
 */
 static inline int uta_ring_insert( void* vr, void* new_data ) {
        ring_t*         r;
+       int64_t inc = 1;                                // used to set the counter in the pfd
 
        if( !RING_FAST ) {                                                              // compiler should drop the conditional when always false
                if( (r = (ring_t*) vr) == NULL ) {
@@ -129,6 +161,13 @@ static inline int uta_ring_insert( void* vr, void* new_data ) {
                return 0;
        }
 
+       write( r->pfd, &inc, sizeof( inc ) );
+/*
+future -- investigate if it's possible only to set/clear when empty or going to empty
+       if( r->tail == r->head ) {                                                              // turn on ready if ring was empty
+       }
+*/
+
        r->data[r->head] = new_data;
        r->head++;
        if( r->head >= r->nelements ) {