Support multiple error callbacks
Move from a single callback model to allow multiple registrations.
Created a separate mutex to guard the callback in order to simplify
the process of invoking the callbacks safely without holding the
main lock.
Change-Id: Id09aedda785e99b31c70cba1681a2ee392e9b06c
diff --git a/media/libaudioclient/AudioSystem.cpp b/media/libaudioclient/AudioSystem.cpp
index 941cf54..e0ca07e 100644
--- a/media/libaudioclient/AudioSystem.cpp
+++ b/media/libaudioclient/AudioSystem.cpp
@@ -36,10 +36,11 @@
// client singleton for AudioFlinger binder interface
Mutex AudioSystem::gLock;
+Mutex AudioSystem::gLockErrorCallbacks;
Mutex AudioSystem::gLockAPS;
sp<IAudioFlinger> AudioSystem::gAudioFlinger;
sp<AudioSystem::AudioFlingerClient> AudioSystem::gAudioFlingerClient;
-audio_error_callback AudioSystem::gAudioErrorCallback = NULL;
+std::set<audio_error_callback> AudioSystem::gAudioErrorCallbacks;
dynamic_policy_callback AudioSystem::gDynPolicyCallback = NULL;
record_config_callback AudioSystem::gRecordConfigCallback = NULL;
@@ -63,9 +64,7 @@
if (gAudioFlingerClient == NULL) {
gAudioFlingerClient = new AudioFlingerClient();
} else {
- if (gAudioErrorCallback) {
- gAudioErrorCallback(NO_ERROR);
- }
+ reportError(NO_ERROR);
}
binder->linkToDeath(gAudioFlingerClient);
gAudioFlinger = interface_cast<IAudioFlinger>(binder);
@@ -500,19 +499,16 @@
void AudioSystem::AudioFlingerClient::binderDied(const wp<IBinder>& who __unused)
{
- audio_error_callback cb = NULL;
{
Mutex::Autolock _l(AudioSystem::gLock);
AudioSystem::gAudioFlinger.clear();
- cb = gAudioErrorCallback;
}
// clear output handles and stream to output map caches
clearIoCache();
- if (cb) {
- cb(DEAD_OBJECT);
- }
+ reportError(DEAD_OBJECT);
+
ALOGW("AudioFlinger server died!");
}
@@ -717,10 +713,23 @@
return NO_ERROR;
}
-/* static */ void AudioSystem::setErrorCallback(audio_error_callback cb)
+/* static */ uintptr_t AudioSystem::addErrorCallback(audio_error_callback cb)
{
- Mutex::Autolock _l(gLock);
- gAudioErrorCallback = cb;
+ Mutex::Autolock _l(gLockErrorCallbacks);
+ gAudioErrorCallbacks.insert(cb);
+ return reinterpret_cast<uintptr_t>(cb);
+}
+
+/* static */ void AudioSystem::removeErrorCallback(uintptr_t cb) {
+ Mutex::Autolock _l(gLockErrorCallbacks);
+ gAudioErrorCallbacks.erase(reinterpret_cast<audio_error_callback>(cb));
+}
+
+/* static */ void AudioSystem::reportError(status_t err) {
+ Mutex::Autolock _l(gLockErrorCallbacks);
+ for (auto callback : gAudioErrorCallbacks) {
+ callback(err);
+ }
}
/*static*/ void AudioSystem::setDynPolicyCallback(dynamic_policy_callback cb)
diff --git a/media/libaudioclient/include/media/AudioSystem.h b/media/libaudioclient/include/media/AudioSystem.h
index c4b528e..201acca 100644
--- a/media/libaudioclient/include/media/AudioSystem.h
+++ b/media/libaudioclient/include/media/AudioSystem.h
@@ -27,6 +27,7 @@
#include <media/IAudioFlingerClient.h>
#include <media/IAudioPolicyServiceClient.h>
#include <media/MicrophoneInfo.h>
+#include <set>
#include <system/audio.h>
#include <system/audio_effect.h>
#include <system/audio_policy.h>
@@ -107,7 +108,16 @@
static status_t setParameters(const String8& keyValuePairs);
static String8 getParameters(const String8& keys);
- static void setErrorCallback(audio_error_callback cb);
+ // Registers an error callback. When this callback is invoked, it means all
+ // state implied by this interface has been reset.
+ // Returns a token that can be used for un-registering.
+ // Might block while callbacks are being invoked.
+ static uintptr_t addErrorCallback(audio_error_callback cb);
+
+ // Un-registers a callback previously added with addErrorCallback.
+ // Might block while callbacks are being invoked.
+ static void removeErrorCallback(uintptr_t cb);
+
static void setDynPolicyCallback(dynamic_policy_callback cb);
static void setRecordConfigCallback(record_config_callback);
@@ -560,15 +570,19 @@
static const sp<AudioFlingerClient> getAudioFlingerClient();
static sp<AudioIoDescriptor> getIoDescriptor(audio_io_handle_t ioHandle);
+ // Invokes all registered error callbacks with the given error code.
+ static void reportError(status_t err);
+
static sp<AudioFlingerClient> gAudioFlingerClient;
static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
friend class AudioFlingerClient;
friend class AudioPolicyServiceClient;
- static Mutex gLock; // protects gAudioFlinger and gAudioErrorCallback,
+ static Mutex gLock; // protects gAudioFlinger
+ static Mutex gLockErrorCallbacks; // protects gAudioErrorCallbacks
static Mutex gLockAPS; // protects gAudioPolicyService and gAudioPolicyServiceClient
static sp<IAudioFlinger> gAudioFlinger;
- static audio_error_callback gAudioErrorCallback;
+ static std::set<audio_error_callback> gAudioErrorCallbacks;
static dynamic_policy_callback gDynPolicyCallback;
static record_config_callback gRecordConfigCallback;