[cpu-profiler] Make tracing-based CPU profile ids unique

Using CpuProfile pointer is not safe for id as the profile objects
can be recreated on the same memory address.
Use sequential numbers instead.

Change-Id: I7253605819055bc3396b797f9ce27669e8c2584d
Reviewed-on: https://chromium-review.googlesource.com/1123325Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Alexei Filippov <alph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54180}

src/profiler/profile-generator.cc

@@ -386,6 +386,8 @@ void ProfileTree::TraverseDepthFirst(Callback* callback) {
 
 using v8::tracing::TracedValue;
 
+std::atomic<uint32_t> CpuProfile::last_id_;
+
 CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
                        bool record_samples, ProfilingMode mode)
     : title_(title),
@@ -394,12 +396,13 @@ CpuProfile::CpuProfile(CpuProfiler* profiler, const char* title,
       start_time_(base::TimeTicks::HighResolutionNow()),
       top_down_(profiler->isolate()),
       profiler_(profiler),
-      streaming_next_sample_(0) {
+      streaming_next_sample_(0),
+      id_(++last_id_) {
   auto value = TracedValue::Create();
   value->SetDouble("startTime",
                    (start_time_ - base::TimeTicks()).InMicroseconds());
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
-                              "Profile", this, "data", std::move(value));
+                              "Profile", id_, "data", std::move(value));
 }
 
 void CpuProfile::AddPath(base::TimeTicks timestamp,
@@ -491,7 +494,7 @@ void CpuProfile::StreamPendingTraceEvents() {
   }
 
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
-                              "ProfileChunk", this, "data", std::move(value));
+                              "ProfileChunk", id_, "data", std::move(value));
 }
 
 void CpuProfile::FinishProfile() {
@@ -500,7 +503,7 @@ void CpuProfile::FinishProfile() {
   auto value = TracedValue::Create();
   value->SetDouble("endTime", (end_time_ - base::TimeTicks()).InMicroseconds());
   TRACE_EVENT_SAMPLE_WITH_ID1(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profiler"),
-                              "ProfileChunk", this, "data", std::move(value));
+                              "ProfileChunk", id_, "data", std::move(value));
 }
 
 void CpuProfile::Print() {

src/profiler/profile-generator.h

@@ -5,6 +5,7 @@
 #ifndef V8_PROFILER_PROFILE_GENERATOR_H_
 #define V8_PROFILER_PROFILE_GENERATOR_H_
 
+#include <atomic>
 #include <deque>
 #include <limits>
 #include <map>
@@ -261,7 +262,6 @@ class ProfileNode {
   DISALLOW_COPY_AND_ASSIGN(ProfileNode);
 };
 
-
 class ProfileTree {
  public:
   explicit ProfileTree(Isolate* isolate);
@@ -354,6 +354,9 @@ class CpuProfile {
   ProfileTree top_down_;
   CpuProfiler* const profiler_;
   size_t streaming_next_sample_;
+  uint32_t id_;
+
+  static std::atomic<uint32_t> last_id_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfile);
 };