Adding Skia Recorder to Render Engine

To start recording run:
adb shell setprop debug.renderengine.capture_skia_ms 1000

File will be stored in the /data directory on the device:
adb shell ls -al /data/user/
adb pull /data/user/re_skiacapture_<timestamp>.mskp

The recording will stop after MS specified. To reset the
recording, set the capture_skia_ms flag to a new time.
When recording is finished, the capture_skia_ms flag will
be set to 0 to avoid circular recording.

Bug: 173805658
Test: Turn on the flag. Turn off the flag. Pull the file from
      the device. Open it in Skia Debugger.
Change-Id: Iea478245c267fb4b26f980417d96acd7273bfb55
diff --git a/libs/renderengine/skia/debug/CommonPool.cpp b/libs/renderengine/skia/debug/CommonPool.cpp
new file mode 100644
index 0000000..bf15300
--- /dev/null
+++ b/libs/renderengine/skia/debug/CommonPool.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright 2020 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 "CommonPool.h"
+
+#undef LOG_TAG
+#define LOG_TAG "RenderEngine"
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include <sys/resource.h>
+#include <utils/Trace.h>
+
+#include <system/thread_defs.h>
+#include <array>
+
+namespace android {
+namespace renderengine {
+namespace skia {
+
+CommonPool::CommonPool() {
+    ATRACE_CALL();
+
+    CommonPool* pool = this;
+    // Create 2 workers
+    for (int i = 0; i < THREAD_COUNT; i++) {
+        std::thread worker([pool, i] {
+            {
+                std::array<char, 20> name{"reTask"};
+                snprintf(name.data(), name.size(), "reTask%d", i);
+                auto self = pthread_self();
+                pthread_setname_np(self, name.data());
+                setpriority(PRIO_PROCESS, 0, ANDROID_PRIORITY_FOREGROUND);
+            }
+            pool->workerLoop();
+        });
+        worker.detach();
+    }
+}
+
+CommonPool& CommonPool::instance() {
+    static CommonPool pool;
+    return pool;
+}
+
+void CommonPool::post(Task&& task) {
+    instance().enqueue(std::move(task));
+}
+
+void CommonPool::enqueue(Task&& task) {
+    std::unique_lock lock(mLock);
+    while (mWorkQueue.size() > QUEUE_SIZE) {
+        lock.unlock();
+        ALOGW("Queue is full: %d, waiting before adding more tasks.", QUEUE_SIZE);
+        usleep(100);
+        lock.lock();
+    }
+    mWorkQueue.push(std::move(task));
+    if (mWaitingThreads == THREAD_COUNT || (mWaitingThreads > 0 && mWorkQueue.size() > 1)) {
+        mCondition.notify_one();
+    }
+}
+
+void CommonPool::workerLoop() {
+    std::unique_lock lock(mLock);
+    while (true) {
+        if (mWorkQueue.size() == 0) {
+            mWaitingThreads++;
+            mCondition.wait(lock);
+            mWaitingThreads--;
+        }
+        // Need to double-check that work is still available now that we have the lock
+        // It may have already been grabbed by a different thread
+        while (mWorkQueue.size() > 0) {
+            auto work = mWorkQueue.front();
+            mWorkQueue.pop();
+            lock.unlock();
+            work();
+            lock.lock();
+        }
+    }
+}
+
+} // namespace skia
+} // namespace renderengine
+} // namespace android
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