EGL: Refactor multifile blobcache

After more testing, it became apparent that we need to
avoid accessing the filesystem to have decent speed.

This CL does that by:
* Moving the multifile cache to a class
* Tracking all entries in a bookkeeping system
* Remove use of STL for read/write
* Keep recent entries in a hot cache
* Deferring file writes to a worker thread
* Allowing devices to opt in via config

For more data and details on the design philosophy:
go/improving-multifile-blobcache-speed

Also added a new sequence of tests that bypass EGL
and directly invoke the mulfifile cache.

Test: pubg_mobile_launch ANGLE trace
Test: /data/nativetest64/EGL_test/EGL_test
Test: /data/nativetest64/libEGL_test/libEGL_test
Bug: b/266725576
Change-Id: Ia19147522a6f68f05fbe47c1545e4c9d69e513c6
diff --git a/opengl/libs/EGL/egl_cache.cpp b/opengl/libs/EGL/egl_cache.cpp
index 1e8a348..b00ee33 100644
--- a/opengl/libs/EGL/egl_cache.cpp
+++ b/opengl/libs/EGL/egl_cache.cpp
@@ -14,6 +14,8 @@
  ** limitations under the License.
  */
 
+// #define LOG_NDEBUG 0
+
 #include "egl_cache.h"
 
 #include <android-base/properties.h>
@@ -25,22 +27,19 @@
 #include <thread>
 
 #include "../egl_impl.h"
-#include "egl_cache_multifile.h"
 #include "egl_display.h"
 
 // Monolithic cache size limits.
-static const size_t maxKeySize = 12 * 1024;
-static const size_t maxValueSize = 64 * 1024;
-static const size_t maxTotalSize = 32 * 1024 * 1024;
+static const size_t kMaxMonolithicKeySize = 12 * 1024;
+static const size_t kMaxMonolithicValueSize = 64 * 1024;
+static const size_t kMaxMonolithicTotalSize = 2 * 1024 * 1024;
 
 // The time in seconds to wait before saving newly inserted monolithic cache entries.
-static const unsigned int deferredSaveDelay = 4;
+static const unsigned int kDeferredMonolithicSaveDelay = 4;
 
-// Multifile cache size limit
-constexpr size_t kMultifileCacheByteLimit = 64 * 1024 * 1024;
-
-// Delay before cleaning up multifile cache entries
-static const unsigned int deferredMultifileCleanupDelaySeconds = 1;
+// Multifile cache size limits
+constexpr uint32_t kMultifileHotCacheLimit = 8 * 1024 * 1024;
+constexpr uint32_t kMultifileCacheByteLimit = 32 * 1024 * 1024;
 
 namespace android {
 
@@ -68,10 +67,7 @@
 // egl_cache_t definition
 //
 egl_cache_t::egl_cache_t()
-      : mInitialized(false),
-        mMultifileMode(false),
-        mCacheByteLimit(maxTotalSize),
-        mMultifileCleanupPending(false) {}
+      : mInitialized(false), mMultifileMode(false), mCacheByteLimit(kMaxMonolithicTotalSize) {}
 
 egl_cache_t::~egl_cache_t() {}
 
@@ -85,7 +81,7 @@
     std::lock_guard<std::mutex> lock(mMutex);
 
     egl_connection_t* const cnx = &gEGLImpl;
-    if (cnx->dso && cnx->major >= 0 && cnx->minor >= 0) {
+    if (display && cnx->dso && cnx->major >= 0 && cnx->minor >= 0) {
         const char* exts = display->disp.queryString.extensions;
         size_t bcExtLen = strlen(BC_EXT_STR);
         size_t extsLen = strlen(exts);
@@ -114,14 +110,36 @@
         }
     }
 
-    // Allow forcing monolithic cache for debug purposes
-    if (base::GetProperty("debug.egl.blobcache.multifilemode", "") == "false") {
-        ALOGD("Forcing monolithic cache due to debug.egl.blobcache.multifilemode == \"false\"");
+    // Check the device config to decide whether multifile should be used
+    if (base::GetBoolProperty("ro.egl.blobcache.multifile", false)) {
+        mMultifileMode = true;
+        ALOGV("Using multifile EGL blobcache");
+    }
+
+    // Allow forcing the mode for debug purposes
+    std::string mode = base::GetProperty("debug.egl.blobcache.multifile", "");
+    if (mode == "true") {
+        ALOGV("Forcing multifile cache due to debug.egl.blobcache.multifile == %s", mode.c_str());
+        mMultifileMode = true;
+    } else if (mode == "false") {
+        ALOGV("Forcing monolithic cache due to debug.egl.blobcache.multifile == %s", mode.c_str());
         mMultifileMode = false;
     }
 
     if (mMultifileMode) {
-        mCacheByteLimit = kMultifileCacheByteLimit;
+        mCacheByteLimit = static_cast<size_t>(
+                base::GetUintProperty<uint32_t>("ro.egl.blobcache.multifile_limit",
+                                                kMultifileCacheByteLimit));
+
+        // Check for a debug value
+        int debugCacheSize = base::GetIntProperty("debug.egl.blobcache.multifile_limit", -1);
+        if (debugCacheSize >= 0) {
+            ALOGV("Overriding cache limit %zu with %i from debug.egl.blobcache.multifile_limit",
+                  mCacheByteLimit, debugCacheSize);
+            mCacheByteLimit = debugCacheSize;
+        }
+
+        ALOGV("Using multifile EGL blobcache limit of %zu bytes", mCacheByteLimit);
     }
 
     mInitialized = true;
@@ -133,10 +151,10 @@
         mBlobCache->writeToFile();
     }
     mBlobCache = nullptr;
-    if (mMultifileMode) {
-        checkMultifileCacheSize(mCacheByteLimit);
+    if (mMultifileBlobCache) {
+        mMultifileBlobCache->finish();
     }
-    mMultifileMode = false;
+    mMultifileBlobCache = nullptr;
     mInitialized = false;
 }
 
@@ -151,20 +169,8 @@
 
     if (mInitialized) {
         if (mMultifileMode) {
-            setBlobMultifile(key, keySize, value, valueSize, mFilename);
-
-            if (!mMultifileCleanupPending) {
-                mMultifileCleanupPending = true;
-                // Kick off a thread to cull cache files below limit
-                std::thread deferredMultifileCleanupThread([this]() {
-                    sleep(deferredMultifileCleanupDelaySeconds);
-                    std::lock_guard<std::mutex> lock(mMutex);
-                    // Check the size of cache and remove entries to stay under limit
-                    checkMultifileCacheSize(mCacheByteLimit);
-                    mMultifileCleanupPending = false;
-                });
-                deferredMultifileCleanupThread.detach();
-            }
+            MultifileBlobCache* mbc = getMultifileBlobCacheLocked();
+            mbc->set(key, keySize, value, valueSize);
         } else {
             BlobCache* bc = getBlobCacheLocked();
             bc->set(key, keySize, value, valueSize);
@@ -172,7 +178,7 @@
             if (!mSavePending) {
                 mSavePending = true;
                 std::thread deferredSaveThread([this]() {
-                    sleep(deferredSaveDelay);
+                    sleep(kDeferredMonolithicSaveDelay);
                     std::lock_guard<std::mutex> lock(mMutex);
                     if (mInitialized && mBlobCache) {
                         mBlobCache->writeToFile();
@@ -196,15 +202,21 @@
 
     if (mInitialized) {
         if (mMultifileMode) {
-            return getBlobMultifile(key, keySize, value, valueSize, mFilename);
+            MultifileBlobCache* mbc = getMultifileBlobCacheLocked();
+            return mbc->get(key, keySize, value, valueSize);
         } else {
             BlobCache* bc = getBlobCacheLocked();
             return bc->get(key, keySize, value, valueSize);
         }
     }
+
     return 0;
 }
 
+void egl_cache_t::setCacheMode(EGLCacheMode cacheMode) {
+    mMultifileMode = (cacheMode == EGLCacheMode::Multifile);
+}
+
 void egl_cache_t::setCacheFilename(const char* filename) {
     std::lock_guard<std::mutex> lock(mMutex);
     mFilename = filename;
@@ -216,7 +228,7 @@
     if (!mMultifileMode) {
         // If we're not in multifile mode, ensure the cache limit is only being lowered,
         // not increasing above the hard coded platform limit
-        if (cacheByteLimit > maxTotalSize) {
+        if (cacheByteLimit > kMaxMonolithicTotalSize) {
             return;
         }
     }
@@ -226,8 +238,8 @@
 
 size_t egl_cache_t::getCacheSize() {
     std::lock_guard<std::mutex> lock(mMutex);
-    if (mMultifileMode) {
-        return getMultifileCacheSize();
+    if (mMultifileBlobCache) {
+        return mMultifileBlobCache->getTotalSize();
     }
     if (mBlobCache) {
         return mBlobCache->getSize();
@@ -237,9 +249,18 @@
 
 BlobCache* egl_cache_t::getBlobCacheLocked() {
     if (mBlobCache == nullptr) {
-        mBlobCache.reset(new FileBlobCache(maxKeySize, maxValueSize, mCacheByteLimit, mFilename));
+        mBlobCache.reset(new FileBlobCache(kMaxMonolithicKeySize, kMaxMonolithicValueSize,
+                                           mCacheByteLimit, mFilename));
     }
     return mBlobCache.get();
 }
 
+MultifileBlobCache* egl_cache_t::getMultifileBlobCacheLocked() {
+    if (mMultifileBlobCache == nullptr) {
+        mMultifileBlobCache.reset(
+                new MultifileBlobCache(mCacheByteLimit, kMultifileHotCacheLimit, mFilename));
+    }
+    return mMultifileBlobCache.get();
+}
+
 }; // namespace android