From 484d5fd6cfaf7abdd6d20b9838bbdac8c97bba2d Mon Sep 17 00:00:00 2001
From: Nicolas Cian <[EMAIL REDACTED]>
Date: Wed, 5 Oct 2022 13:19:38 +0200
Subject: [PATCH] audio open: ensure 2 devices don't get the same id
---
src/audio/SDL_audio.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index e2f7412c994e..e33e41dbc33e 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -1313,7 +1313,7 @@ open_audio_device(const char *devname, int iscapture,
return 0;
}
- /* !!! FIXME: there is a race condition here if two devices open from two threads at once. */
+ SDL_LockMutex(current_audio.detectionLock);
/* Find an available device ID... */
for (id = min_id - 1; id < SDL_arraysize(open_devices); id++) {
if (open_devices[id] == NULL) {
@@ -1323,6 +1323,7 @@ open_audio_device(const char *devname, int iscapture,
if (id == SDL_arraysize(open_devices)) {
SDL_SetError("Too many open audio devices");
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
@@ -1330,6 +1331,7 @@ open_audio_device(const char *devname, int iscapture,
obtained = &_obtained;
}
if (!prepare_audiospec(desired, obtained)) {
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
@@ -1351,6 +1353,7 @@ open_audio_device(const char *devname, int iscapture,
if ((iscapture) && (current_audio.impl.OnlyHasDefaultCaptureDevice)) {
if ((devname) && (SDL_strcmp(devname, DEFAULT_INPUT_DEVNAME) != 0)) {
SDL_SetError("No such device");
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
devname = NULL;
@@ -1358,11 +1361,13 @@ open_audio_device(const char *devname, int iscapture,
for (i = 0; i < SDL_arraysize(open_devices); i++) {
if ((open_devices[i]) && (open_devices[i]->iscapture)) {
SDL_SetError("Audio device already open");
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
}
} else if ((!iscapture) && (current_audio.impl.OnlyHasDefaultOutputDevice)) {
if ((devname) && (SDL_strcmp(devname, DEFAULT_OUTPUT_DEVNAME) != 0)) {
+ SDL_UnlockMutex(current_audio.detectionLock);
SDL_SetError("No such device");
return 0;
}
@@ -1370,6 +1375,7 @@ open_audio_device(const char *devname, int iscapture,
for (i = 0; i < SDL_arraysize(open_devices); i++) {
if ((open_devices[i]) && (!open_devices[i]->iscapture)) {
+ SDL_UnlockMutex(current_audio.detectionLock);
SDL_SetError("Audio device already open");
return 0;
}
@@ -1382,20 +1388,19 @@ open_audio_device(const char *devname, int iscapture,
It might still need to open a device based on the string for,
say, a network audio server, but this optimizes some cases. */
SDL_AudioDeviceItem *item;
- SDL_LockMutex(current_audio.detectionLock);
for (item = iscapture ? current_audio.inputDevices : current_audio.outputDevices; item; item = item->next) {
if ((item->handle != NULL) && (SDL_strcmp(item->name, devname) == 0)) {
handle = item->handle;
break;
}
}
- SDL_UnlockMutex(current_audio.detectionLock);
}
if (!current_audio.impl.AllowsArbitraryDeviceNames) {
/* has to be in our device list, or the default device. */
if ((handle == NULL) && (devname != NULL)) {
SDL_SetError("No such device.");
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
}
@@ -1403,6 +1408,7 @@ open_audio_device(const char *devname, int iscapture,
device = (SDL_AudioDevice *) SDL_calloc(1, sizeof (SDL_AudioDevice));
if (device == NULL) {
SDL_OutOfMemory();
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
device->id = id + 1;
@@ -1419,6 +1425,7 @@ open_audio_device(const char *devname, int iscapture,
device->mixer_lock = SDL_CreateMutex();
if (device->mixer_lock == NULL) {
close_audio_device(device);
+ SDL_UnlockMutex(current_audio.detectionLock);
SDL_SetError("Couldn't create mixer lock");
return 0;
}
@@ -1433,6 +1440,7 @@ open_audio_device(const char *devname, int iscapture,
if (current_audio.impl.OpenDevice(device, devname) < 0) {
close_audio_device(device);
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
@@ -1488,6 +1496,7 @@ open_audio_device(const char *devname, int iscapture,
if (!device->stream) {
close_audio_device(device);
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
}
@@ -1497,6 +1506,7 @@ open_audio_device(const char *devname, int iscapture,
device->buffer_queue = SDL_NewDataQueue(SDL_AUDIOBUFFERQUEUE_PACKETLEN, obtained->size * 2);
if (!device->buffer_queue) {
close_audio_device(device);
+ SDL_UnlockMutex(current_audio.detectionLock);
SDL_SetError("Couldn't create audio buffer queue");
return 0;
}
@@ -1514,6 +1524,7 @@ open_audio_device(const char *devname, int iscapture,
device->work_buffer = (Uint8 *) SDL_malloc(device->work_buffer_len);
if (device->work_buffer == NULL) {
close_audio_device(device);
+ SDL_UnlockMutex(current_audio.detectionLock);
SDL_OutOfMemory();
return 0;
}
@@ -1534,9 +1545,11 @@ open_audio_device(const char *devname, int iscapture,
if (device->thread == NULL) {
close_audio_device(device);
SDL_SetError("Couldn't create audio thread");
+ SDL_UnlockMutex(current_audio.detectionLock);
return 0;
}
}
+ SDL_UnlockMutex(current_audio.detectionLock);
return device->id;
}