stabilize MPV playback, adjust some intervals and timeouts. Make TaskProcess give more proper process state - so ProcessService wont kill process in state of starting or shutdowning

src/main/java/com/mykola2312/mptv/mpv/MPV.java

@@ -18,6 +18,7 @@ import org.slf4j.LoggerFactory;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.mykola2312.mptv.task.TaskProcess;
+import com.mykola2312.mptv.task.TaskProcessState;
 
 public class MPV implements TaskProcess {
     private static final Logger logger = LoggerFactory.getLogger(MPV.class);
@@ -25,6 +26,8 @@ public class MPV implements TaskProcess {
     private final String url;
     private Process process;
 
+    private TaskProcessState state = TaskProcessState.STOPPED;
+
     public MPV(String url) {
         this.url = url;
     }
@@ -131,7 +134,10 @@ public class MPV implements TaskProcess {
 
     @Override
     public boolean spawn() {
+        if (state == TaskProcessState.STARTING) return false;
         try {
+            state = TaskProcessState.STARTING;
+
             process = Runtime.getRuntime().exec(new String[] {
                 "mpv", "--vo=gpu", "--ao=pulse", "--fullscreen", "--input-ipc-server=" + MPV_SOCKET_PATH, url
             });
@@ -147,10 +153,19 @@ public class MPV implements TaskProcess {
             return false;
         }
 
-        return process.isAlive();
+        if (process.isAlive()) {
+            state = TaskProcessState.RUNNING;
+            return true;
+        } else {
+            state = TaskProcessState.STOPPED;
+            return false;
+        }
     }
 
-    private static final float PLAYBACK_TIME_DELAY = 2.5f;
+    @Override
+    public TaskProcessState getTaskState() {
+        return state;
+    }
 
     private boolean checkPlayback() {
         try {
@@ -182,7 +197,7 @@ public class MPV implements TaskProcess {
 
                     return true;
                 } else {
-                    boolean playbackChanged = (playbackTime - lastPlaybackTime) > PLAYBACK_TIME_DELAY;
+                    boolean playbackChanged = (playbackTime - lastPlaybackTime) > 0.1;
                 
                     lastPlaybackTime = playbackTime;
                     return playbackChanged;
@@ -212,6 +227,8 @@ public class MPV implements TaskProcess {
 
     @Override
     public void stop() {
+        state = TaskProcessState.STOPPING;
+
         if (reader != null) reader.running = false;
         if (readerThread != null) readerThread.interrupt();
         if (socket != null) closeConnection();
@@ -220,6 +237,8 @@ public class MPV implements TaskProcess {
         readerThread = null;
         socket = null;
         process = null;
+
+        state = TaskProcessState.STOPPED;
     }
 
     private int requestIdCounter = 0;

src/main/java/com/mykola2312/mptv/piir/PiIR.java

@@ -12,6 +12,7 @@ import org.slf4j.LoggerFactory;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.mykola2312.mptv.Main;
 import com.mykola2312.mptv.task.TaskProcess;
+import com.mykola2312.mptv.task.TaskProcessState;
 import com.mykola2312.mptv.ui.MenuAction;
 
 public class PiIR implements TaskProcess {
@@ -24,6 +25,8 @@ public class PiIR implements TaskProcess {
     private Process process = null;
     private InputStream input = null;
 
+    private TaskProcessState state;
+
     private class PiIRReader implements Runnable {
         private final PiIR piir;
         private final InputStream input;
@@ -118,7 +121,10 @@ public class PiIR implements TaskProcess {
 
     @Override
     public boolean spawn() {
+        if (state == TaskProcessState.STARTING) return false;
         try {
+            state = TaskProcessState.STARTING;
+
             process = Runtime.getRuntime().exec(new String[] {
                 "unbuffer", exec, "dump", "--gpio", String.valueOf(gpio)
             });
@@ -131,7 +137,17 @@ public class PiIR implements TaskProcess {
         readerThread = new Thread(reader);
         readerThread.start();
 
-        return isAlive();
+        if (process.isAlive()) {
+            state = TaskProcessState.RUNNING;
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    @Override
+    public TaskProcessState getTaskState() {
+        return state;
     }
 
     @Override
@@ -141,6 +157,8 @@ public class PiIR implements TaskProcess {
 
     @Override
     public void stop() {
+        state = TaskProcessState.STOPPING;
+
         if (reader != null) reader.running = false;
         if (readerThread != null) readerThread.interrupt();
         if (input != null) {
@@ -154,6 +172,8 @@ public class PiIR implements TaskProcess {
         reader = null;
         readerThread = null;
         process = null;
+
+        state = TaskProcessState.STOPPED;
     }
     
     public void handleDump(PiIRDump dump) {

src/main/java/com/mykola2312/mptv/task/ProcessService.java

@@ -28,7 +28,7 @@ public class ProcessService implements Task {
     @Override
     public void dispatch() {
         for (TaskProcess process : processes) {
-            if (!process.isAlive()) {
+            if (process.getTaskState() == TaskProcessState.RUNNING && !process.isAlive()) {
                 logger.info("restarting process " + process.toString());
                 try {
                     process.stop();

src/main/java/com/mykola2312/mptv/task/TaskProcess.java

@@ -2,6 +2,7 @@ package com.mykola2312.mptv.task;
 
 public interface TaskProcess {
     public boolean spawn();
+    public TaskProcessState getTaskState();
     public boolean isAlive();
     public void stop();
 }

src/main/java/com/mykola2312/mptv/task/TaskProcessState.java

@@ -0,0 +1,8 @@
+package com.mykola2312.mptv.task;
+
+public enum TaskProcessState {
+    STOPPED,
+    STARTING,
+    RUNNING,
+    STOPPING
+}