AudioFlinger: Clarify effect creation comments and warnings
Test: CTS audio effect tests, instrumented test
Bug: 128633662
Change-Id: I31e4cbec6c34d2419d2f7bbcced98e8bbb8ce78d
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index b8f88cf..43260c2 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -3297,7 +3297,8 @@
// output threads.
// If output is 0 here, sessionId is neither SESSION_OUTPUT_STAGE nor SESSION_OUTPUT_MIX
// because of code checking output when entering the function.
- // Note: io is never 0 when creating an effect on an input
+ // Note: io is never AUDIO_IO_HANDLE_NONE when creating an effect on an input by APM.
+ // An AudioEffect created from the Java API will have io as AUDIO_IO_HANDLE_NONE.
if (io == AUDIO_IO_HANDLE_NONE) {
// look for the thread where the specified audio session is present
io = findIoHandleBySessionId_l(sessionId, mPlaybackThreads);
@@ -3307,6 +3308,25 @@
if (io == AUDIO_IO_HANDLE_NONE) {
io = findIoHandleBySessionId_l(sessionId, mMmapThreads);
}
+
+ // If you wish to create a Record preprocessing AudioEffect in Java,
+ // you MUST create an AudioRecord first and keep it alive so it is picked up above.
+ // Otherwise it will fail when created on a Playback thread by legacy
+ // handling below. Ditto with Mmap, the associated Mmap track must be created
+ // before creating the AudioEffect or the io handle must be specified.
+ //
+ // Detect if the effect is created after an AudioRecord is destroyed.
+ if (getOrphanEffectChain_l(sessionId).get() != nullptr) {
+ ALOGE("%s: effect %s with no specified io handle is denied because the AudioRecord"
+ " for session %d no longer exists",
+ __func__, desc.name, sessionId);
+ lStatus = PERMISSION_DENIED;
+ goto Exit;
+ }
+
+ // Legacy handling of creating an effect on an expired or made-up
+ // session id. We think that it is a Playback effect.
+ //
// If no output thread contains the requested session ID, default to
// first output. The effect chain will be moved to the correct output
// thread when a track with the same session ID is created