commit 5964e73774b381748013b91d04dfb6fc60f533ee
author Eric Laurent <elaurent@google.com> Thu Jul 09 01:56:20 2009 -0700
committer Eric Laurent <elaurent@google.com> Thu Jul 09 01:56:20 2009 -0700
tree 3ed233d830f2d7741411c4984262da5636cf6662
parent c52d55c5404a09a3845a322f50577fc4c125a86d

Fix issue 1946033: dialer deadlocks and/or ANRs when using dialpad in-call

The cause is very likely that the WaveGenerator *lpWaveGen returned by lpToneGen->mWaveGens.valueFor(lFrequency) just before calling lpWaveGen->getSamples(lpOut, lGenSmp, lWaveCmd) is invalid. The frequency lFrequency is not part of the frequencies in mWaveGens.
This can happen if a different tone is started while the callback function is active: The state is changed to TONE_RESTARTING and the call to prepareWave() at line 1226 will change the tone descriptor pointed to by mpToneDesc as well as the content of mWaveGens. However, mpToneDesc was cached in a local variable lpToneDesc when entering the callback and is not reloaded when exiting prepareWave(). This causes a mismatch between the tone frequencies listed in lpToneDesc and the frequencies present in mWaveGens.
This regression was introduced in change 973 when mpToneDesc was cached in a local variable.

media/libmedia/ToneGenerator.cpp

diff --git a/media/libmedia/ToneGenerator.cpp b/media/libmedia/ToneGenerator.cpp
index c22cd53..5435da7 100644
--- a/media/libmedia/ToneGenerator.cpp
+++ b/media/libmedia/ToneGenerator.cpp
@@ -1225,6 +1225,8 @@
             LOGV("Cbk restarting track\n");
             if (lpToneGen->prepareWave()) {
                 lpToneGen->mState = TONE_STARTING;
+                // must reload lpToneDesc as prepareWave() may change mpToneDesc
+                lpToneDesc = lpToneGen->mpToneDesc;
             } else {
                 LOGW("Cbk restarting prepareWave() failed\n");
                 lpToneGen->mState = TONE_IDLE;