small adjustments, many enhancements to rktplayer

shm.cpp

@@ -256,6 +256,8 @@ public:
 #include <unistd.h>
 #include <errno.h>
 #include <semaphore.h>
+#include <time.h>
+#include <assert.h>
 
 
 class ShmApi : public ShmApiBase
@@ -338,22 +340,41 @@ public:
     }
 };
 
+#define TIME_NS_IN_MSEC  1000000ULL
+
 class ShmSemApi {
     private:
         sem_t *_sem;
         char  *_name;
         bool   _owner;
 
+    private:
+        void makeSemTimeoutTime(struct timespec *ts, int ms) {
+            clock_gettime(CLOCK_REALTIME, ts);
+            ts->tv_sec += ms / 1000;
+            ts->tv_nsec += (ms % 1000) * TIME_NS_IN_MSEC;
+            if (ts->tv_nsec >= 1000000000L) {
+                ts->tv_sec++;
+                ts->tv_nsec = ts->tv_nsec - 1000000000L;
+            }
+        }
+
     public:
         void post() {
             sem_post(_sem);
         }
 
-        void wait() {
-            int r = sem_wait(_sem);
+        bool wait(int ms) {
+            struct timespec ts;
+            makeSemTimeoutTime(&ts, ms);
+            int r = sem_timedwait(_sem, &ts);
             if (r != 0) {
-                ERROR2("sem_wait error: %d, %s\n", errno, strerror(errno));
+                if (errno != ETIMEDOUT) {
+                    ERROR2("sem_wait error: %d, %s\n", errno, strerror(errno));
+                }
+                return false;
             }
+            return true;
         }
 
         bool trywait() {
@@ -365,6 +386,11 @@ class ShmSemApi {
             return (r == 0);
         }
 
+    public:
+        void takeOwnership() {
+            _owner = true;
+        }
+
     public:
         ShmSemApi(const char *n, bool owner) {
             _name = strdup(n);