There is a complain from Valgrind about invalid memory access in snd_device_name_hint(-1, ..) // -1 means all cards.

It looks like the problem is actually because we use -1 to loop through all the soundcards.
And this patch will loop through the soundcard manually, which should resolve the Valgrind problem.

Bug=96207
Test=media_unittests with Valgrind

Review URL: http://codereview.chromium.org/7888011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@101240 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 23 insertions, 35 deletions

diff --git a/media/audio/linux/alsa_wrapper.cc b/media/audio/linux/alsa_wrapper.cc
index 563bccb..69b703e 100644
--- a/media/audio/linux/alsa_wrapper.cc
+++ b/media/audio/linux/alsa_wrapper.cc
@@ -29,6 +29,10 @@ int AlsaWrapper::DeviceNameFreeHint(void** hints) {
   return snd_device_name_free_hint(hints);
 }
 
+int AlsaWrapper::CardNext(int* rcard) {
+  return snd_card_next(rcard);
+}
+
 int AlsaWrapper::PcmClose(snd_pcm_t* handle) {
   return snd_pcm_close(handle);
 }
diff --git a/media/audio/linux/alsa_wrapper.h b/media/audio/linux/alsa_wrapper.h
index efe93d0..85cf68a 100644
--- a/media/audio/linux/alsa_wrapper.h
+++ b/media/audio/linux/alsa_wrapper.h
@@ -19,6 +19,7 @@ class MEDIA_EXPORT AlsaWrapper {
   virtual int DeviceNameHint(int card, const char* iface, void*** hints);
   virtual char* DeviceNameGetHint(const void* hint, const char* id);
   virtual int DeviceNameFreeHint(void** hints);
+  virtual int CardNext(int* rcard);
 
   virtual int PcmOpen(snd_pcm_t** handle, const char* name,
                       snd_pcm_stream_t stream, int mode);
diff --git a/media/audio/linux/audio_manager_linux.cc b/media/audio/linux/audio_manager_linux.cc
index caab797..930c6b2 100644
--- a/media/audio/linux/audio_manager_linux.cc
+++ b/media/audio/linux/audio_manager_linux.cc
@@ -63,25 +63,29 @@ bool AudioManagerLinux::HasAudioInputDevices() {
   }
 
   // Constants specified by the ALSA API for device hints.
-  static const int kGetAllDevices = -1;
   static const char kPcmInterfaceName[] = "pcm";
   bool has_device = false;
   void** hints = NULL;
-
-  // Use the same approach to find the devices as in
-  // AlsaPcmOutputStream::FindDeviceForChannels
-  // Get Alsa device hints.
-  int error = wrapper_->DeviceNameHint(kGetAllDevices,
-                                       kPcmInterfaceName,
-                                       &hints);
-  if (error == 0) {
-    has_device = HasAnyValidAudioInputDevice(hints);
-  } else {
-    LOG(ERROR) << "Unable to get device hints: " << wrapper_->StrError(error);
+  int card = -1;
+
+  // Loop through the sound cards to get Alsa device hints.
+  // Don't use snd_device_name_hint(-1,..) since there is a access violation
+  // inside this ALSA API with libasound.so.2.0.0.
+  while (!wrapper_->CardNext(&card) && (card >= 0) && !has_device) {
+    int error = wrapper_->DeviceNameHint(card,
+                                         kPcmInterfaceName,
+                                         &hints);
+    if (error == 0) {
+      has_device = HasAnyValidAudioInputDevice(hints);
+
+      // Destroy the hints now that we're done with it.
+      wrapper_->DeviceNameFreeHint(hints);
+      hints = NULL;
+    } else {
+      LOG(ERROR) << "Unable to get device hints: " << wrapper_->StrError(error);
+    }
   }
 
-  // Destroy the hint now that we're done with it.
-  wrapper_->DeviceNameFreeHint(hints);
   return has_device;
 }
 
diff --git a/tools/valgrind/memcheck/suppressions.txt b/tools/valgrind/memcheck/suppressions.txt
index 2bc604b..6a9dbd4 100644
--- a/tools/valgrind/memcheck/suppressions.txt
+++ b/tools/valgrind/memcheck/suppressions.txt
@@ -4761,27 +4761,6 @@
    fun:_ZN27ScopedRunnableMethodFactoryIN3net21HttpStreamFactoryImpl3JobEE14RunnableMethodIMS2_FvvE6Tuple0E3RunEv
 }
 {
-   bug_96207_a
-   Memcheck:Addr1
-   ...
-   fun:snd_device_name_hint
-   fun:_ZN11AlsaWrapper14DeviceNameHintEiPKcPPPv
-}
-{
-   bug_96207_b
-   Memcheck:Addr4
-   ...
-   fun:snd_device_name_hint
-   fun:_ZN11AlsaWrapper14DeviceNameHintEiPKcPPPv
-}
-{
-   bug_96207_c
-   Memcheck:Addr4
-   ...
-   fun:snd_config_iterator_next
-   fun:_ZN11AlsaWrapper14DeviceNameHintEiPKcPPPv
-}
-{
    bug_96295
    Memcheck:Leak
    fun:_Znw*