DroidDeck/tools/directaudio/microphone-toggle.patch

--- a/directaudio-relay.c
+++ b/directaudio-relay.c
@@ -70,6 +70,9 @@
  * session log captures it too. Event-level lines are always on: they fire a
  * handful of times per session and are what makes a field report actionable. */
 static int g_verbose;
+static const char *g_mic_control;
+static int g_mic_enabled = 1;
+static pthread_mutex_t g_mic_operations = PTHREAD_MUTEX_INITIALIZER;
 
 static void rlog(const char *fmt, ...)
 {
@@ -735,6 +738,9 @@
     (void)user;
     if (aq != __atomic_load_n(&g_mic.cq, __ATOMIC_SEQ_CST) && __atomic_load_n(&g_mic.cq, __ATOMIC_SEQ_CST))
         return AAUDIO_CALLBACK_RESULT_CONTINUE;
+    if (!__atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE))
+        memset(audioData, 0, numFrames * g_mic.in_channels *
+               (g_mic.in_format == AAUDIO_FORMAT_PCM_I16 ? sizeof(int16_t) : sizeof(float)));
     __atomic_add_fetch(&g_mic.cb_count, 1, __ATOMIC_RELAXED);
 
     pthread_mutex_lock(&g_clients_lock);
@@ -832,13 +838,14 @@
     AAudioStream *aq = NULL;
     int start = 0, stop = 0;
 
+    pthread_mutex_lock(&g_mic_operations);
     pthread_mutex_lock(&g_mic.lock);
     g_mic.want += delta;
     if (g_mic.want < 0) g_mic.want = 0;
     if (g_mic.cq)
     {
-        if (g_mic.want > 0 && !g_mic.started) { g_mic.started = 1; start = 1; aq = g_mic.cq; }
-        if (g_mic.want == 0 && g_mic.started) { g_mic.started = 0; stop = 1; aq = g_mic.cq; }
+        if (g_mic.want > 0 && __atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE) && !g_mic.started) { g_mic.started = 1; start = 1; aq = g_mic.cq; }
+        if ((g_mic.want == 0 || !__atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE)) && g_mic.started) { g_mic.started = 0; stop = 1; aq = g_mic.cq; }
     }
     pthread_mutex_unlock(&g_mic.lock);
 
@@ -856,8 +863,23 @@
     else if (stop)
     {
         AAudioStream_requestStop(aq);
-        REVENT("mic stop (%s was the last consumer)", who);
-    }
+        REVENT("mic stop (%s)", who);
+    }
+    pthread_mutex_unlock(&g_mic_operations);
+}
+
+static void mic_control_update(void)
+{
+    FILE *f;
+    int enabled;
+    if (!g_mic_control) return;
+    f = fopen(g_mic_control, "r");
+    enabled = f && fgetc(f) == '1';
+    if (f) fclose(f);
+    if (enabled == __atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE)) return;
+    __atomic_store_n(&g_mic_enabled, enabled, __ATOMIC_RELEASE);
+    mic_want(0, "session toggle");
+    REVENT("mic enabled=%d", enabled);
 }
 
 static void *mic_reopen_thread(void *unused)
@@ -870,8 +892,9 @@
 
         __atomic_store_n(&g_mic.reopen_redo, 0, __ATOMIC_SEQ_CST);
 
+        pthread_mutex_lock(&g_mic_operations);
         pthread_mutex_lock(&g_mic.lock);
-        want_start = g_mic.want > 0;
+        want_start = g_mic.want > 0 && __atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE);
         pthread_mutex_unlock(&g_mic.lock);
 
         if (open_input(&neu) == AAUDIO_OK)
@@ -902,6 +925,7 @@
             AAudioStream_close(old);
         }
 
+        pthread_mutex_unlock(&g_mic_operations);
         if (__atomic_load_n(&g_mic.reopen_redo, __ATOMIC_SEQ_CST)) { usleep(20000); continue; }
         __atomic_store_n(&g_mic.reopen_running, 0, __ATOMIC_SEQ_CST);
         if (!__atomic_load_n(&g_mic.reopen_redo, __ATOMIC_SEQ_CST)) break;
@@ -1348,7 +1372,8 @@
 /* ---- housekeeping: watchdog tick + mailbox watch, once a second ------------- */
 static void *housekeeping_thread(void *unused)
 {
-    struct timespec iv = { 1, 0 };
+    struct timespec iv = { 0, 100000000 };
+    unsigned tick = 0;
 
     (void)unused;
     for (;;)
@@ -1357,6 +1382,8 @@
         int reload = 0;
 
         nanosleep(&iv, NULL);
+        mic_control_update();
+        if (++tick % 10) continue;
 
         if (g_rt_path[0])
         {
@@ -1402,8 +1429,9 @@
     {
         if (!strcmp(argv[i], "--socket") && i + 1 < argc) path = argv[++i];
         else if (!strcmp(argv[i], "--mic-fifo") && i + 1 < argc) fifo_path = argv[++i];
+        else if (!strcmp(argv[i], "--mic-control") && i + 1 < argc) g_mic_control = argv[++i];
         else if (!strcmp(argv[i], "--log")) g_verbose = 1;
-        else { fprintf(stderr, "usage: directaudio-relay --socket <path> [--mic-fifo <path>] [--log]\n"); return 2; }
+        else { fprintf(stderr, "usage: directaudio-relay --socket <path> [--mic-fifo <path>] [--mic-control <path>] [--log]\n"); return 2; }
     }
     if (!path)
     {
@@ -1429,6 +1457,8 @@
     chmod(path, 0666);
     if (listen(srv, 8) != 0) { REVENT("listen: %d", errno); return 1; }
 
+    mic_control_update();
+    REVENT("mic enabled=%d", __atomic_load_n(&g_mic_enabled, __ATOMIC_ACQUIRE));
     if (pthread_create(&th, NULL, housekeeping_thread, NULL) == 0) pthread_detach(th);
     if (fifo_path && fifo_setup(fifo_path) != 0)
         REVENT("mic-fifo: disabled");