EGL: add deferred saving of the cache

This change causes any insertions into the EGL cache to trigger an
attempt to save the cache contents to disk.  The save operation is
deferred to allow multiple cache insertions to be batched up.

Change-Id: I6cfec9c0dbbef94d3f8880860e2a365dccc296c7

1 files changed, 27 insertions, 0 deletions

diff --git a/opengl/libs/EGL/egl_cache.cpp b/opengl/libs/EGL/egl_cache.cpp
index aa40d5888ce5..522421b1d43f 100644
--- a/opengl/libs/EGL/egl_cache.cpp
+++ b/opengl/libs/EGL/egl_cache.cpp
@@ -34,6 +34,9 @@ static const size_t maxTotalSize = 64 * 1024;
 static const char* cacheFileMagic = "EGL$";
 static const size_t cacheFileHeaderSize = 8;
 
+// The time in seconds to wait before saving newly inserted cache entries.
+static const unsigned int deferredSaveDelay = 4;
+
 // ----------------------------------------------------------------------------
 namespace android {
 // ----------------------------------------------------------------------------
@@ -128,6 +131,30 @@ void egl_cache_t::setBlob(const void* key, EGLsizei keySize, const void* value,
     if (mInitialized) {
         sp<BlobCache> bc = getBlobCacheLocked();
         bc->set(key, keySize, value, valueSize);
+
+        if (!mSavePending) {
+            class DeferredSaveThread : public Thread {
+            public:
+                DeferredSaveThread() : Thread(false) {}
+
+                virtual bool threadLoop() {
+                    sleep(deferredSaveDelay);
+                    egl_cache_t* c = egl_cache_t::get();
+                    Mutex::Autolock lock(c->mMutex);
+                    if (c->mInitialized) {
+                        c->saveBlobCacheLocked();
+                    }
+                    c->mSavePending = false;
+                    return false;
+                }
+            };
+
+            // The thread will hold a strong ref to itself until it has finished
+            // running, so there's no need to keep a ref around.
+            sp<Thread> deferredSaveThread(new DeferredSaveThread());
+            mSavePending = true;
+            deferredSaveThread->run();
+        }
     }
 }