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/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