[Android] Better fix for #2480, pause/resume audio

src/audio/SDL_audio.c

@@ -1348,26 +1348,17 @@ void
 SDL_PauseAudioDevice(SDL_AudioDeviceID devid, int pause_on)
 {
     SDL_AudioDevice *device = get_audio_device(devid);
-    if (device && device->paused != pause_on) {
-        if (pause_on) {
-            current_audio.impl.LockDevice(device);
-        }
+    if (device) {
+        current_audio.impl.LockDevice(device);
         device->paused = pause_on;
-        if (!pause_on) {
-            current_audio.impl.UnlockDevice(device);
-        }
+        current_audio.impl.UnlockDevice(device);
     }
 }
 
 void
 SDL_PauseAudio(int pause_on)
 {
-    int id;
-    for (id = 0; id < SDL_arraysize(open_devices); id++) {
-        if (open_devices[id] != NULL) {
-            SDL_PauseAudioDevice(id+1, pause_on);
-        }
-    }
+    SDL_PauseAudioDevice(1, pause_on);
 }
 
 

src/audio/android/SDL_androidaudio.c

@@ -32,7 +32,7 @@
 
 #include <android/log.h>
 
-static void * audioDevice;
+static SDL_AudioDevice* audioDevice = NULL;
 
 static int
 AndroidAUD_OpenDevice(_THIS, const char *devname, int iscapture)
@@ -50,6 +50,11 @@ AndroidAUD_OpenDevice(_THIS, const char *devname, int iscapture)
 
     audioDevice = this;
     
+    this->hidden = (struct SDL_PrivateAudioData *) SDL_calloc(1, (sizeof *this->hidden));
+    if (this->hidden == NULL) {
+        return SDL_OutOfMemory();
+    }
+
     test_format = SDL_FirstAudioFormat(this->spec.format);
     while (test_format != 0) { /* no "UNKNOWN" constant */
         if ((test_format == AUDIO_U8) || (test_format == AUDIO_S16LSB)) {
@@ -110,6 +115,10 @@ AndroidAUD_CloseDevice(_THIS)
     Android_JNI_CloseAudioDevice();
 
     if (audioDevice == this) {
+        if (audioDevice->hidden != NULL) {
+            SDL_free(this->hidden);
+            this->hidden = NULL;
+        }
         audioDevice = NULL;
     }
 }
@@ -135,6 +144,41 @@ AudioBootStrap ANDROIDAUD_bootstrap = {
     "android", "SDL Android audio driver", AndroidAUD_Init, 0
 };
 
+/* Pause (block) all non already paused audio devices by taking their mixer lock */
+void AndroidAUD_PauseDevices(void)
+{
+    /* TODO: Handle multiple devices? */
+    struct SDL_PrivateAudioData *private;
+    if(audioDevice != NULL && audioDevice->hidden != NULL) {
+        private = (struct SDL_PrivateAudioData *) audioDevice->hidden;
+        if (audioDevice->paused) {
+            /* The device is already paused, leave it alone */
+            private->resume = SDL_FALSE;
+        }
+        else {
+            SDL_LockMutex(audioDevice->mixer_lock);
+            audioDevice->paused = SDL_TRUE;
+            private->resume = SDL_TRUE;
+        }
+    }
+}
+
+/* Resume (unblock) all non already paused audio devices by releasing their mixer lock */
+void AndroidAUD_ResumeDevices(void)
+{
+    /* TODO: Handle multiple devices? */
+    struct SDL_PrivateAudioData *private;
+    if(audioDevice != NULL && audioDevice->hidden != NULL) {
+        private = (struct SDL_PrivateAudioData *) audioDevice->hidden;
+        if (private->resume) {
+            audioDevice->paused = SDL_FALSE;
+            private->resume = SDL_FALSE;
+            SDL_UnlockMutex(audioDevice->mixer_lock);
+        }
+    }
+}
+
+
 #endif /* SDL_AUDIO_DRIVER_ANDROID */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/audio/android/SDL_androidaudio.h

@@ -30,6 +30,8 @@
 
 struct SDL_PrivateAudioData
 {
+    /* Resume device if it was paused automatically */
+    int resume;
 };
 
 static void AndroidAUD_CloseDevice(_THIS);

src/video/android/SDL_androidevents.c

@@ -29,8 +29,11 @@
 #include "SDL_events.h"
 #include "SDL_androidwindow.h"
 
+
 void android_egl_context_backup();
 void android_egl_context_restore();
+void AndroidAUD_ResumeDevices(void);
+void AndroidAUD_PauseDevices(void);
 
 void 
 android_egl_context_restore() 
@@ -74,14 +77,14 @@ Android_PumpEvents(_THIS)
     if (isPaused && !isPausing) {
         /* Make sure this is the last thing we do before pausing */
         android_egl_context_backup();
-        SDL_PauseAudio(1);
+        AndroidAUD_PauseDevices();
         if(SDL_SemWait(Android_ResumeSem) == 0) {
 #else
     if (isPaused) {
         if(SDL_SemTryWait(Android_ResumeSem) == 0) {
 #endif
             isPaused = 0;
-            SDL_PauseAudio(0);
+            AndroidAUD_ResumeDevices();
             /* Restore the GL Context from here, as this operation is thread dependent */
             if (!SDL_HasEvent(SDL_QUIT)) {
                 android_egl_context_restore();
@@ -104,7 +107,7 @@ Android_PumpEvents(_THIS)
 #else
         if(SDL_SemTryWait(Android_PauseSem) == 0) {
             android_egl_context_backup();
-            SDL_PauseAudio(1);
+            AndroidAUD_PauseDevices();
             isPaused = 1;
         }
 #endif