commit e2f8b60e3aff70e234430602f80146e9fdc48674
author zhenjun.zhang <zhenjun.zhang1@unisoc.com> Tue Dec 07 19:31:05 2021 +0800
committer Andy Hung <hunga@google.com> Tue Dec 07 16:36:00 2021 +0000
tree 8c7bb3efd188b5293dc7a8d9c050c41249e08a4d
parent fe5ce1bdfe2d03ebb79fbcfd5634d9f7d9365ddd

AudioTrack: Fix Java offload blocking in AudioTrack::write

With Java offload support, both the AudioTrack::write() and the
AudioTrackThread obtainBuffer/waitStreamEndDone can be blocked
on the AudioTrackShared Proxy futex.

Prior to the Java offload support, AudioTrack::write() was not
called simultaneous to the AudioTrackThread
obtainBuffer/waitStreamEndDone, thus only one thread was
blocked on the futex.

Solution: Change the FUTEX_WAKE to wake more than one thread

Test: invoke android.media.cts.AudioTrackOffloadTest#testMP3AudioTrackOffload
repeatly, check if the case may blocked in AudioTrack::write (syscall)
Bug: 209612569
Change-Id: I40d531863486f66e65c2bfe7d8e00156c804232d

media/libaudioclient/AudioTrackShared.cpp

diff --git a/media/libaudioclient/AudioTrackShared.cpp b/media/libaudioclient/AudioTrackShared.cpp
index 35719be..da27dc8 100644
--- a/media/libaudioclient/AudioTrackShared.cpp
+++ b/media/libaudioclient/AudioTrackShared.cpp
@@ -409,7 +409,7 @@
         android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
         // it seems that a FUTEX_WAKE_PRIVATE will not wake a FUTEX_WAIT, even within same process
         (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE,
-                1);
+                INT_MAX);
     }
 }
 
@@ -419,7 +419,7 @@
     if (!(android_atomic_or(CBLK_INTERRUPT, &cblk->mFlags) & CBLK_INTERRUPT)) {
         android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
         (void) syscall(__NR_futex, &cblk->mFutex, mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE,
-                1);
+                INT_MAX);
     }
 }
 
@@ -747,7 +747,7 @@
             int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
             if (!(old & CBLK_FUTEX_WAKE)) {
                 (void) syscall(__NR_futex, &cblk->mFutex,
-                        mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1);
+                        mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, INT_MAX);
             }
         }
         mFlushed += (newFront - front) & mask;
@@ -917,7 +917,7 @@
         int32_t old = android_atomic_or(CBLK_FUTEX_WAKE, &cblk->mFutex);
         if (!(old & CBLK_FUTEX_WAKE)) {
             (void) syscall(__NR_futex, &cblk->mFutex,
-                    mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, 1);
+                    mClientInServer ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE, INT_MAX);
         }
     }