libgui: add EGL Image Tracking for debug

Track EGL images allocated by libgui to help debug memory leaks

Test: monkey
Bug: 137514000
Change-Id: I0b193c0fdb7a4c07d7c2e5d06063e3dc01b5a57b
diff --git a/libs/gui/DebugEGLImageTracker.cpp b/libs/gui/DebugEGLImageTracker.cpp
new file mode 100644
index 0000000..ab6f364
--- /dev/null
+++ b/libs/gui/DebugEGLImageTracker.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/stringprintf.h>
+#include <cutils/properties.h>
+#include <gui/DebugEGLImageTracker.h>
+
+#include <cinttypes>
+#include <unordered_map>
+
+using android::base::StringAppendF;
+
+std::mutex DebugEGLImageTracker::mInstanceLock;
+std::atomic<DebugEGLImageTracker *> DebugEGLImageTracker::mInstance;
+
+class DebugEGLImageTrackerNoOp : public DebugEGLImageTracker {
+public:
+    DebugEGLImageTrackerNoOp() = default;
+    ~DebugEGLImageTrackerNoOp() override = default;
+    void create(const char * /*from*/) override {}
+    void destroy(const char * /*from*/) override {}
+
+    void dump(std::string & /*result*/) override {}
+};
+
+class DebugEGLImageTrackerImpl : public DebugEGLImageTracker {
+public:
+    DebugEGLImageTrackerImpl() = default;
+    ~DebugEGLImageTrackerImpl() override = default;
+    void create(const char * /*from*/) override;
+    void destroy(const char * /*from*/) override;
+
+    void dump(std::string & /*result*/) override;
+
+private:
+    std::mutex mLock;
+    std::unordered_map<std::string, int64_t> mCreateTracker;
+    std::unordered_map<std::string, int64_t> mDestroyTracker;
+
+    int64_t mTotalCreated = 0;
+    int64_t mTotalDestroyed = 0;
+};
+
+DebugEGLImageTracker *DebugEGLImageTracker::getInstance() {
+    std::lock_guard lock(mInstanceLock);
+    if (mInstance == nullptr) {
+        char value[PROPERTY_VALUE_MAX];
+        property_get("debug.sf.enable_egl_image_tracker", value, "0");
+        const bool enabled = static_cast<bool>(atoi(value));
+
+        if (enabled) {
+            mInstance = new DebugEGLImageTrackerImpl();
+        } else {
+            mInstance = new DebugEGLImageTrackerNoOp();
+        }
+    }
+
+    return mInstance;
+}
+
+void DebugEGLImageTrackerImpl::create(const char *from) {
+    std::lock_guard lock(mLock);
+    mCreateTracker[from]++;
+    mTotalCreated++;
+}
+
+void DebugEGLImageTrackerImpl::destroy(const char *from) {
+    std::lock_guard lock(mLock);
+    mDestroyTracker[from]++;
+    mTotalDestroyed++;
+}
+
+void DebugEGLImageTrackerImpl::dump(std::string &result) {
+    std::lock_guard lock(mLock);
+    StringAppendF(&result, "Live EGL Image objects: %" PRIi64 "\n",
+                  mTotalCreated - mTotalDestroyed);
+    StringAppendF(&result, "Total EGL Image created: %" PRIi64 "\n", mTotalCreated);
+    for (const auto &[from, count] : mCreateTracker) {
+        StringAppendF(&result, "\t%s: %" PRIi64 "\n", from.c_str(), count);
+    }
+    StringAppendF(&result, "Total EGL Image destroyed: %" PRIi64 "\n", mTotalDestroyed);
+    for (const auto &[from, count] : mDestroyTracker) {
+        StringAppendF(&result, "\t%s: %" PRIi64 "\n", from.c_str(), count);
+    }
+}