Add tracing thread for RenderEngine's fences

RenderEngine doesn't always render to FramebufferSurface, so tracing
that is built into BufferQueue is lost. Add a tracing thread so that
screenshots and caching can also have GPU work traced.

Bug: 280684246
Bug: 269822044
Test: perfetto
Change-Id: I067430f6b6b588dd3046d1cf66d0a3fc8465746d
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 80fed98..bf34987 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -217,6 +217,7 @@
         "DebugEGLImageTracker.cpp",
         "DisplayEventDispatcher.cpp",
         "DisplayEventReceiver.cpp",
+        "FenceMonitor.cpp",
         "GLConsumer.cpp",
         "IConsumerListener.cpp",
         "IGraphicBufferConsumer.cpp",
diff --git a/libs/gui/FenceMonitor.cpp b/libs/gui/FenceMonitor.cpp
new file mode 100644
index 0000000..230c81a
--- /dev/null
+++ b/libs/gui/FenceMonitor.cpp
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2023 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.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include <gui/FenceMonitor.h>
+#include <gui/TraceUtils.h>
+#include <log/log.h>
+
+#include <thread>
+
+namespace android::gui {
+
+FenceMonitor::FenceMonitor(const char* name) : mName(name), mFencesQueued(0), mFencesSignaled(0) {
+    std::thread thread(&FenceMonitor::loop, this);
+    pthread_setname_np(thread.native_handle(), mName);
+    thread.detach();
+}
+
+void FenceMonitor::queueFence(const sp<Fence>& fence) {
+    char message[64];
+
+    std::lock_guard<std::mutex> lock(mMutex);
+    if (fence->getSignalTime() != Fence::SIGNAL_TIME_PENDING) {
+        snprintf(message, sizeof(message), "%s fence %u has signaled", mName, mFencesQueued);
+        ATRACE_NAME(message);
+        // Need an increment on both to make the trace number correct.
+        mFencesQueued++;
+        mFencesSignaled++;
+        return;
+    }
+    snprintf(message, sizeof(message), "Trace %s fence %u", mName, mFencesQueued);
+    ATRACE_NAME(message);
+
+    mQueue.push_back(fence);
+    mCondition.notify_one();
+    mFencesQueued++;
+    ATRACE_INT(mName, int32_t(mQueue.size()));
+}
+
+void FenceMonitor::loop() {
+    while (true) {
+        threadLoop();
+    }
+}
+
+void FenceMonitor::threadLoop() {
+    sp<Fence> fence;
+    uint32_t fenceNum;
+    {
+        std::unique_lock<std::mutex> lock(mMutex);
+        while (mQueue.empty()) {
+            mCondition.wait(lock);
+        }
+        fence = mQueue[0];
+        fenceNum = mFencesSignaled;
+    }
+    {
+        char message[64];
+        snprintf(message, sizeof(message), "waiting for %s %u", mName, fenceNum);
+        ATRACE_NAME(message);
+
+        status_t result = fence->waitForever(message);
+        if (result != OK) {
+            ALOGE("Error waiting for fence: %d", result);
+        }
+    }
+    {
+        std::lock_guard<std::mutex> lock(mMutex);
+        mQueue.pop_front();
+        mFencesSignaled++;
+        ATRACE_INT(mName, int32_t(mQueue.size()));
+    }
+}
+
+} // namespace android::gui
\ No newline at end of file
diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index a5cf8d6..3a1e600 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -30,6 +30,7 @@
 #include <android/gui/DisplayStatInfo.h>
 #include <android/native_window.h>
 
+#include <gui/FenceMonitor.h>
 #include <gui/TraceUtils.h>
 #include <utils/Log.h>
 #include <utils/NativeHandle.h>
@@ -545,82 +546,6 @@
     return NO_ERROR;
 }
 
-class FenceMonitor {
-public:
-    explicit FenceMonitor(const char* name) : mName(name), mFencesQueued(0), mFencesSignaled(0) {
-        std::thread thread(&FenceMonitor::loop, this);
-        pthread_setname_np(thread.native_handle(), mName);
-        thread.detach();
-    }
-
-    void queueFence(const sp<Fence>& fence) {
-        char message[64];
-
-        std::lock_guard<std::mutex> lock(mMutex);
-        if (fence->getSignalTime() != Fence::SIGNAL_TIME_PENDING) {
-            snprintf(message, sizeof(message), "%s fence %u has signaled", mName, mFencesQueued);
-            ATRACE_NAME(message);
-            // Need an increment on both to make the trace number correct.
-            mFencesQueued++;
-            mFencesSignaled++;
-            return;
-        }
-        snprintf(message, sizeof(message), "Trace %s fence %u", mName, mFencesQueued);
-        ATRACE_NAME(message);
-
-        mQueue.push_back(fence);
-        mCondition.notify_one();
-        mFencesQueued++;
-        ATRACE_INT(mName, int32_t(mQueue.size()));
-    }
-
-private:
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wmissing-noreturn"
-    void loop() {
-        while (true) {
-            threadLoop();
-        }
-    }
-#pragma clang diagnostic pop
-
-    void threadLoop() {
-        sp<Fence> fence;
-        uint32_t fenceNum;
-        {
-            std::unique_lock<std::mutex> lock(mMutex);
-            while (mQueue.empty()) {
-                mCondition.wait(lock);
-            }
-            fence = mQueue[0];
-            fenceNum = mFencesSignaled;
-        }
-        {
-            char message[64];
-            snprintf(message, sizeof(message), "waiting for %s %u", mName, fenceNum);
-            ATRACE_NAME(message);
-
-            status_t result = fence->waitForever(message);
-            if (result != OK) {
-                ALOGE("Error waiting for fence: %d", result);
-            }
-        }
-        {
-            std::lock_guard<std::mutex> lock(mMutex);
-            mQueue.pop_front();
-            mFencesSignaled++;
-            ATRACE_INT(mName, int32_t(mQueue.size()));
-        }
-    }
-
-    const char* mName;
-    uint32_t mFencesQueued;
-    uint32_t mFencesSignaled;
-    std::deque<sp<Fence>> mQueue;
-    std::condition_variable mCondition;
-    std::mutex mMutex;
-};
-
 void Surface::getDequeueBufferInputLocked(
         IGraphicBufferProducer::DequeueBufferInput* dequeueInput) {
     LOG_ALWAYS_FATAL_IF(dequeueInput == nullptr, "input is null");
@@ -694,7 +619,7 @@
     ALOGE_IF(fence == nullptr, "Surface::dequeueBuffer: received null Fence! buf=%d", buf);
 
     if (CC_UNLIKELY(atrace_is_tag_enabled(ATRACE_TAG_GRAPHICS))) {
-        static FenceMonitor hwcReleaseThread("HWC release");
+        static gui::FenceMonitor hwcReleaseThread("HWC release");
         hwcReleaseThread.queueFence(fence);
     }
 
@@ -893,7 +818,7 @@
         sp<GraphicBuffer>& gbuf(mSlots[slot].buffer);
 
         if (CC_UNLIKELY(atrace_is_tag_enabled(ATRACE_TAG_GRAPHICS))) {
-            static FenceMonitor hwcReleaseThread("HWC release");
+            static gui::FenceMonitor hwcReleaseThread("HWC release");
             hwcReleaseThread.queueFence(output.fence);
         }
 
@@ -1163,7 +1088,7 @@
     mQueueBufferCondition.broadcast();
 
     if (CC_UNLIKELY(atrace_is_tag_enabled(ATRACE_TAG_GRAPHICS))) {
-        static FenceMonitor gpuCompletionThread("GPU completion");
+        static gui::FenceMonitor gpuCompletionThread("GPU completion");
         gpuCompletionThread.queueFence(fence);
     }
 }
diff --git a/libs/gui/include/gui/FenceMonitor.h b/libs/gui/include/gui/FenceMonitor.h
new file mode 100644
index 0000000..62cedde
--- /dev/null
+++ b/libs/gui/include/gui/FenceMonitor.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2023 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.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <deque>
+#include <mutex>
+
+#include <ui/Fence.h>
+
+namespace android::gui {
+
+class FenceMonitor {
+public:
+    explicit FenceMonitor(const char* name);
+    void queueFence(const sp<Fence>& fence);
+
+private:
+    void loop();
+    void threadLoop();
+
+    const char* mName;
+    uint32_t mFencesQueued;
+    uint32_t mFencesSignaled;
+    std::deque<sp<Fence>> mQueue;
+    std::condition_variable mCondition;
+    std::mutex mMutex;
+};
+
+} // namespace android::gui
\ No newline at end of file