Integrate Chrome tracing with V8 (WIP)

include/v8-tracing.h

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_V8_TRACING_H_
+#define V8_V8_TRACING_H_
+
+#include <stdint.h>
+
+namespace v8 {
+
+// This will mark the trace event as disabled by default. The user will need
+// to explicitly enable the event.
+#define TRACE_DISABLED_BY_DEFAULT(name) "disabled-by-default-" name
+
+class EventTracer {
+ public:
+  typedef uint64_t Handle;
+
+  static EventTracer* GetInstance();
+
+  static void SetInstance(EventTracer* tracer) {
+    delete (EventTracer::gInstance);
+    EventTracer::gInstance = tracer;
+  }
+
+  virtual ~EventTracer() {}
+
+  // The pointer returned from GetCategoryGroupEnabled() points to a
+  // value with zero or more of the following bits. Used in this class only.
+  // The TRACE_EVENT macros should only use the value as a bool.
+  // These values must be in sync with macro values in trace_event.h in
+  // chromium.
+  enum CategoryGroupEnabledFlags {
+    // Category group enabled for the recording mode.
+    kEnabledForRecording_CategoryGroupEnabledFlags = 1 << 0,
+    // Category group enabled for the monitoring mode.
+    kEnabledForMonitoring_CategoryGroupEnabledFlags = 1 << 1,
+    // Category group enabled by SetEventCallbackEnabled().
+    kEnabledForEventCallback_CategoryGroupEnabledFlags = 1 << 2,
+  };
+
+  virtual const uint8_t* getCategoryGroupEnabled(const char* name) = 0;
+  virtual const char* getCategoryGroupName(
+      const uint8_t* categoryEnabledFlag) = 0;
+
+  virtual EventTracer::Handle addTraceEvent(
+      char phase, const uint8_t* categoryEnabledFlag, const char* name,
+      uint64_t id, int32_t numArgs, const char** argNames,
+      const uint8_t* argTypes, const uint64_t* argValues, uint8_t flags) = 0;
+
+  virtual void updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
+                                        const char* name,
+                                        EventTracer::Handle handle) = 0;
+
+ private:
+  static EventTracer* gInstance;
+};
+}
+
+#endif  // V8_V8_TRACING_H_