commit 28f1351369682801e1bb40a835bdae3c97b73c1c
author Glenn Kasten <gkasten@google.com> Wed Jul 31 12:27:26 2013 -0700
committer Glenn Kasten <gkasten@google.com> Fri Aug 02 16:22:41 2013 -0700
tree eb6e8fad009764ef115c894f017be5b110689b65
parent f36dbfe3d517e9311be0a4d0fd6658380690e84c

AudioRecord callback thread waits for priority boost

Change-Id: Iae38fa4ac20a45751566169213a08a15deb0a2f6

include/media/AudioRecord.h

diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index c65ffe8..596cf93 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -476,6 +476,7 @@
 
     int                     mPreviousPriority;  // before start()
     SchedPolicy             mPreviousSchedulingGroup;
+    bool                    mAwaitBoost;    // thread should wait for priority boost before running
 
     // The proxy should only be referenced while a lock is held because the proxy isn't
     // multi-thread safe.

media/libmedia/AudioRecord.cpp

diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index 0e7e17f..7be7529 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -665,6 +665,26 @@
 nsecs_t AudioRecord::processAudioBuffer(const sp<AudioRecordThread>& thread)
 {
     mLock.lock();
+    if (mAwaitBoost) {
+        mAwaitBoost = false;
+        mLock.unlock();
+        static const int32_t kMaxTries = 5;
+        int32_t tryCounter = kMaxTries;
+        uint32_t pollUs = 10000;
+        do {
+            int policy = sched_getscheduler(0);
+            if (policy == SCHED_FIFO || policy == SCHED_RR) {
+                break;
+            }
+            usleep(pollUs);
+            pollUs <<= 1;
+        } while (tryCounter-- > 0);
+        if (tryCounter < 0) {
+            ALOGE("did not receive expected priority boost on time");
+        }
+        // Run again immediately
+        return 0;
+    }
 
     // Can only reference mCblk while locked
     int32_t flags = android_atomic_and(~CBLK_OVERRUN, &mCblk->mFlags);