Fix blocking DBus device reservation, so it plays nice with others

common/JackControlAPI.cpp

@@ -746,6 +746,14 @@ get_realtime_priority_constraint()
 SERVER_EXPORT jackctl_server_t * jackctl_server_create(
     bool (* on_device_acquire)(const char * device_name),
     void (* on_device_release)(const char * device_name))
+{
+    return jackctl_server_create2(on_device_acquire, on_device_release, NULL);
+}
+
+SERVER_EXPORT jackctl_server_t * jackctl_server_create2(
+    bool (* on_device_acquire)(const char * device_name),
+    void (* on_device_release)(const char * device_name),
+    void (* on_device_reservation_loop)(void))
 {
     struct jackctl_server * server_ptr;
     union jackctl_parameter_value value;
@@ -922,6 +930,7 @@ SERVER_EXPORT jackctl_server_t * jackctl_server_create(
 
     JackServerGlobals::on_device_acquire = on_device_acquire;
     JackServerGlobals::on_device_release = on_device_release;
+    JackServerGlobals::on_device_reservation_loop = on_device_reservation_loop;
 
     if (!jackctl_drivers_load(server_ptr))
     {

common/JackControlAPI.h

@@ -94,6 +94,12 @@ jackctl_server_create(
     bool (* on_device_acquire)(const char * device_name),
     void (* on_device_release)(const char * device_name));
 
+SERVER_EXPORT jackctl_server_t *
+jackctl_server_create2(
+    bool (* on_device_acquire)(const char * device_name),
+    void (* on_device_release)(const char * device_name),
+    void (* on_device_reservation_loop)(void));
+
 SERVER_EXPORT void
 jackctl_server_destroy(
 	jackctl_server_t * server);

common/JackServerGlobals.cpp

@@ -36,6 +36,7 @@ std::map<std::string, int> JackServerGlobals::fInternalsList;
 
 bool (* JackServerGlobals::on_device_acquire)(const char * device_name) = NULL;
 void (* JackServerGlobals::on_device_release)(const char * device_name) = NULL;
+void (* JackServerGlobals::on_device_reservation_loop)(void) = NULL;
 
 int JackServerGlobals::Start(const char* server_name,
                              jack_driver_desc_t* driver_desc,

common/JackServerGlobals.h

@@ -44,6 +44,7 @@ struct SERVER_EXPORT JackServerGlobals
 
     static bool (* on_device_acquire)(const char* device_name);
     static void (* on_device_release)(const char* device_name);
+    static void (* on_device_reservation_loop)(void);
 
     JackServerGlobals();
     ~JackServerGlobals();

common/Jackdmp.cpp

@@ -328,11 +328,11 @@ int main(int argc, char** argv)
     copyright(stdout);
 #if defined(JACK_DBUS) && defined(__linux__)
     if (getenv("JACK_NO_AUDIO_RESERVATION"))
-        server_ctl = jackctl_server_create(NULL, NULL);
+        server_ctl = jackctl_server_create2(NULL, NULL, NULL);
     else
-        server_ctl = jackctl_server_create(audio_acquire, audio_release);
+        server_ctl = jackctl_server_create2(audio_acquire, audio_release, audio_reserve_loop);
 #else
-    server_ctl = jackctl_server_create(NULL, NULL);
+    server_ctl = jackctl_server_create2(NULL, NULL, NULL);
 #endif
     if (server_ctl == NULL) {
         fprintf(stderr, "Failed to create server object\n");

common/jack/control.h

@@ -119,20 +119,33 @@ void
 jackctl_wait_signals(
     jackctl_sigmask_t * signals);
 
+/**
+ * \bold THIS FUNCTION IS DEPRECATED AND SHOULD NOT BE USED IN
+ *  NEW JACK PROJECTS
+ *
+ * @deprecated Please use jackctl_server_create2().
+ */
+jackctl_server_t *
+jackctl_server_create(
+    bool (* on_device_acquire)(const char * device_name),
+    void (* on_device_release)(const char * device_name));
+
 /**
  * Call this function to create server object.
  *
  * @param on_device_acquire - Optional callback to be called before device is acquired. If false is returned, device usage will fail
  * @param on_device_release - Optional callback to be called after device is released.
+ * @param on_device_reservation_loop - Optional callback to be called when looping/idling the reservation.
  *
  * @return server object handle, NULL if creation of server object
  * failed. Successfully created server object must be destroyed with
  * paired call to ::jackctl_server_destroy
  */
 jackctl_server_t *
-jackctl_server_create(
+jackctl_server_create2(
     bool (* on_device_acquire)(const char * device_name),
-    void (* on_device_release)(const char * device_name));
+    void (* on_device_release)(const char * device_name),
+    void (* on_device_reservation_loop)(void));
 
 /**
  * Call this function to destroy server object.

dbus/audio_reserve.c

@@ -128,8 +128,7 @@ SERVER_EXPORT void audio_release(const char * device_name)
 SERVER_EXPORT void audio_reserve_loop()
 {
     if (gConnection != NULL) {
-       while (dbus_connection_read_write_dispatch (gConnection, -1))
-         ; // empty loop body
+       dbus_connection_read_write_dispatch (gConnection, 200);
     }
 }
 

dbus/controller.c

@@ -548,7 +548,7 @@ jack_controller_create(
 
     INIT_LIST_HEAD(&controller_ptr->session_pending_commands);
 
-    controller_ptr->server = jackctl_server_create(on_device_acquire, on_device_release);
+    controller_ptr->server = jackctl_server_create2(on_device_acquire, on_device_release, NULL);
     if (controller_ptr->server == NULL)
     {
         jack_error("Failed to create server object");

example-clients/server_control.cpp

@@ -170,7 +170,7 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	server = jackctl_server_create(NULL, NULL);
+	server = jackctl_server_create2(NULL, NULL, NULL);
     parameters = jackctl_server_get_parameters(server);
 
     /*

linux/alsa/JackAlsaDriver.cpp

@@ -67,6 +67,18 @@ static struct jack_constraint_enum_char_descriptor dither_constraint_descr_array
 namespace Jack
 {
 
+static volatile bool device_reservation_loop_running = false;
+
+static void* on_device_reservation_loop(void*)
+{
+    while (device_reservation_loop_running && JackServerGlobals::on_device_reservation_loop != NULL) {
+        JackServerGlobals::on_device_reservation_loop();
+        usleep(50*1000);
+    }
+
+    return NULL;
+}
+
 int JackAlsaDriver::SetBufferSize(jack_nframes_t buffer_size)
 {
     jack_log("JackAlsaDriver::SetBufferSize %ld", buffer_size);
@@ -344,6 +356,12 @@ int JackAlsaDriver::Open(jack_nframes_t nframes,
         // ALSA driver may have changed the in/out values
         fCaptureChannels = ((alsa_driver_t *)fDriver)->capture_nchannels;
         fPlaybackChannels = ((alsa_driver_t *)fDriver)->playback_nchannels;
+        if (JackServerGlobals::on_device_reservation_loop != NULL) {
+            device_reservation_loop_running = true;
+            if (JackPosixThread::StartImp(&fReservationLoopThread, 0, 0, on_device_reservation_loop, NULL) != 0) {
+                device_reservation_loop_running = false;
+            }
+        }
         return 0;
     } else {
         Close();
@@ -360,6 +378,11 @@ int JackAlsaDriver::Close()
         alsa_driver_delete((alsa_driver_t*)fDriver);
     }
 
+    if (device_reservation_loop_running) {
+        device_reservation_loop_running = false;
+        JackPosixThread::StopImp(fReservationLoopThread);
+    }
+
     if (JackServerGlobals::on_device_release != NULL)
     {
         char audio_name[32];

linux/alsa/JackAlsaDriver.h

@@ -39,6 +39,7 @@ class JackAlsaDriver : public JackAudioDriver
     private:
 
         jack_driver_t* fDriver;
+        jack_native_thread_t fReservationLoopThread;
 
         void UpdateLatencies();