From 7c0d20a753a930507bec09d7f89da83acc86d0da Mon Sep 17 00:00:00 2001
From: Dave Sparks <davidsparks@android.com>
Date: Mon, 26 Oct 2009 16:28:26 -0700
Subject: [PATCH] Run the metadataretriever at background priority. Bug
 2187133.

This change forces metadata retreiver threads to background priority.
Uses an inner class to encapsulate the priority change so that it
automatically restores priority when returning to the client.
---
 .../MetadataRetrieverClient.cpp               | 27 +++++++++++++++++++
 .../MetadataRetrieverClient.h                 | 10 +++++++
 2 files changed, 37 insertions(+)

diff --git a/media/libmediaplayerservice/MetadataRetrieverClient.cpp b/media/libmediaplayerservice/MetadataRetrieverClient.cpp
index ddd4e24d9b7ed..8eabe5def29d1 100644
--- a/media/libmediaplayerservice/MetadataRetrieverClient.cpp
+++ b/media/libmediaplayerservice/MetadataRetrieverClient.cpp
@@ -21,6 +21,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/resource.h>
 #include <dirent.h>
 #include <unistd.h>
 
@@ -38,6 +39,18 @@
 #include "MidiMetadataRetriever.h"
 #include "MetadataRetrieverClient.h"
 
+/* desktop Linux needs a little help with gettid() */
+#if defined(HAVE_GETTID) && !defined(HAVE_ANDROID_OS)
+#define __KERNEL__
+# include <linux/unistd.h>
+#ifdef _syscall0
+_syscall0(pid_t,gettid)
+#else
+pid_t gettid() { return syscall(__NR_gettid);}
+#endif
+#undef __KERNEL__
+#endif
+
 namespace android {
 
 extern player_type getPlayerType(const char* url);
@@ -212,6 +225,7 @@ sp<IMemory> MetadataRetrieverClient::captureFrame()
 {
     LOGV("captureFrame");
     Mutex::Autolock lock(mLock);
+    Priority priority(ANDROID_PRIORITY_BACKGROUND);
     mThumbnail.clear();
     mThumbnailDealer.clear();
     if (mRetriever == NULL) {
@@ -253,6 +267,7 @@ sp<IMemory> MetadataRetrieverClient::extractAlbumArt()
 {
     LOGV("extractAlbumArt");
     Mutex::Autolock lock(mLock);
+    Priority priority(ANDROID_PRIORITY_BACKGROUND);
     mAlbumArt.clear();
     mAlbumArtDealer.clear();
     if (mRetriever == NULL) {
@@ -294,7 +309,19 @@ const char* MetadataRetrieverClient::extractMetadata(int keyCode)
         LOGE("retriever is not initialized");
         return NULL;
     }
+    Priority priority(ANDROID_PRIORITY_BACKGROUND);
     return mRetriever->extractMetadata(keyCode);
 }
 
+MetadataRetrieverClient::Priority::Priority(int newPriority)
+{
+    mOldPriority = getpriority(PRIO_PROCESS, 0);
+    setpriority(PRIO_PROCESS, 0, newPriority);
+}
+
+MetadataRetrieverClient::Priority::~Priority()
+{
+    setpriority(PRIO_PROCESS, 0, mOldPriority);
+}
+
 }; // namespace android
diff --git a/media/libmediaplayerservice/MetadataRetrieverClient.h b/media/libmediaplayerservice/MetadataRetrieverClient.h
index 8cb8ad13f1b07..852d73497fd48 100644
--- a/media/libmediaplayerservice/MetadataRetrieverClient.h
+++ b/media/libmediaplayerservice/MetadataRetrieverClient.h
@@ -54,6 +54,16 @@ public:
 private:
     friend class MediaPlayerService;
 
+    class Priority
+    {
+    public:
+        Priority(int newPriority);
+        ~Priority();
+    private:
+        Priority();
+        int         mOldPriority;
+    };
+
     explicit MetadataRetrieverClient(pid_t pid);
     virtual ~MetadataRetrieverClient();