Add support for Atrace and hook into SkEventTracer framework.

This change is a different version of:
https://skia-review.googlesource.com/c/3269/

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3345

Change-Id: I49d4f2987740d3ad1307f6aba3add0d63a46b22d
Reviewed-on: https://skia-review.googlesource.com/3345
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Greg Daniel <egdaniel@google.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/core/SkATrace.cpp b/src/core/SkATrace.cpp
new file mode 100644
index 0000000000..b40795e4da
--- /dev/null
+++ b/src/core/SkATrace.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkATrace.h"
+
+#include "SkTraceEvent.h"
+
+#ifdef SK_BUILD_FOR_ANDROID
+#include <dlfcn.h>
+#endif
+
+SkATrace::SkATrace() : fBeginSection(nullptr), fEndSection(nullptr), fIsEnabled(nullptr) {
+#ifdef SK_BUILD_FOR_ANDROID
+    if (void* lib = dlopen("libandroid.so", RTLD_NOW | RTLD_LOCAL)) {
+        fBeginSection = (decltype(fBeginSection))dlsym(lib, "ATrace_beginSection");
+        fEndSection = (decltype(fEndSection))dlsym(lib, "ATrace_endSection");
+        fIsEnabled = (decltype(fIsEnabled))dlsym(lib, "ATrace_isEnabled");
+    }
+#endif
+    if (!fIsEnabled) {
+        fIsEnabled = []{ return false; };
+    }
+}
+
+SkEventTracer::Handle SkATrace::addTraceEvent(char phase,
+                                              const uint8_t* categoryEnabledFlag,
+                                              const char* name,
+                                              uint64_t id,
+                                              int numArgs,
+                                              const char** argNames,
+                                              const uint8_t* argTypes,
+                                              const uint64_t* argValues,
+                                              uint8_t flags) {
+    if (fIsEnabled()) {
+        if (TRACE_EVENT_PHASE_COMPLETE == phase ||
+            TRACE_EVENT_PHASE_BEGIN == phase ||
+            TRACE_EVENT_PHASE_INSTANT == phase) {
+            fBeginSection(name);
+        }
+
+        if (TRACE_EVENT_PHASE_END == phase ||
+            TRACE_EVENT_PHASE_INSTANT == phase) {
+            fEndSection();
+        }
+    }
+    return 0;
+}
+
+void SkATrace::updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
+                                        const char* name,
+                                        SkEventTracer::Handle handle) {
+    // This is only ever called from a scoped trace event so we will just end the ATrace section.
+    if (fIsEnabled()) {
+        fEndSection();
+    }
+}
+
+const uint8_t* SkATrace::getCategoryGroupEnabled(const char* name) {
+    // Chrome tracing is setup to not repeatly call this function once it has been initialized. So
+    // we can't use this to do a check for ATrace isEnabled(). Thus we will always return yes here
+    // and then check to see if ATrace is enabled when beginning and ending a section.
+    static uint8_t yes = SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
+    return &yes;
+}
+