Record Chrome trace events in tcmalloc heap profiles

chrome/browser/chrome_browser_main_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chrome_browser_main_linux.h"
 
+#include "base/debug/trace_memory.h"
+
 #if !defined(OS_CHROMEOS)
 #include "chrome/browser/storage_monitor/storage_monitor_linux.h"
 #include "content/public/browser/browser_thread.h"
 #endif
 
 #if defined(USE_LINUX_BREAKPAD)
 #include <stdlib.h>
 
 #include "base/command_line.h"
 #include "base/linux_util.h"
@@ skipping 77 matching lines @@
       breakpad_enabled = getenv(env_vars::kHeadless) != NULL;
     if (!breakpad_enabled)
       breakpad_enabled = CommandLine::ForCurrentProcess()->HasSwitch(
             switches::kEnableCrashReporterForTesting);
   }
 
   return breakpad_enabled;
 }
 #endif  // defined(USE_LINUX_BREAKPAD)
 
+class MemoryDumpHolder : public base::debug::ConvertableToTraceFormat {
+ public:
+  // Takes ownership of dump, which must be a JSON string, allocated with
+  // malloc() and NULL terminated.
+  explicit MemoryDumpHolder(char* dump) : dump_(dump) {}
+  virtual ~MemoryDumpHolder() { free(dump_); }
+
+  // base::debug::ConvertableToTraceFormat overrides:
+  virtual void AppendAsTraceFormat(std::string* out) const OVERRIDE {
+    LOG(ERROR) << "JAMESDEBUG AppendAsTraceFormat dump len " << strlen(dump_);

[James Cook, 2013/05/21 01:45:41]

I'm now seeing this string printed after taking a trace, with a length of about
48000, but still no green dots in the trace viewer.  Any ideas?

+    out->append(dump_);
+  }
+
+ private:
+  char* dump_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemoryDumpHolder);
+};
+
+void DumpMemoryProfile() {
+  // Check to see if tracing is enabled for the memory category.
+  bool enabled;
+  TRACE_EVENT_CATEGORY_GROUP_ENABLED("memory", &enabled);
+  if (enabled) {
+    // We take ownership of this string.
+    char* dump = base::TraceMemoryDumpAsString();
+    scoped_ptr<MemoryDumpHolder> dump_holder(new MemoryDumpHolder(dump));
+    const int kSnapshotId = 1;
+    TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
+        "memory",
+        "memory::Heap",
+        kSnapshotId,
+        dump_holder.PassAs<base::debug::ConvertableToTraceFormat>());
+  }
+  MessageLoop::current()->PostDelayedTask(FROM_HERE,
+                                          base::Bind(&DumpMemoryProfile),
+                                          base::TimeDelta::FromSeconds(10));
+}
+
 }  // namespace
 
 ChromeBrowserMainPartsLinux::ChromeBrowserMainPartsLinux(
     const content::MainFunctionParams& parameters)
     : ChromeBrowserMainPartsPosix(parameters) {
 }
 
 ChromeBrowserMainPartsLinux::~ChromeBrowserMainPartsLinux() {
 }
 
@@ skipping 20 matching lines @@
 }
 
 void ChromeBrowserMainPartsLinux::PostProfileInit() {
 #if !defined(OS_CHROMEOS)
   storage_monitor_->Init();
 #endif
 
   ChromeBrowserMainPartsPosix::PostProfileInit();
 }
 
+void ChromeBrowserMainPartsLinux::PreMainMessageLoopRun() {
+  ChromeBrowserMainPartsPosix::PreMainMessageLoopRun();
+
+  // TODO(jamescook): This could be moved earlier in startup to capture more
+  // startup allocations.
+  base::TraceMemoryStart();
+
+  // Dump a heap profile every 10 seconds, forever.
+  MessageLoop::current()->PostDelayedTask(FROM_HERE,
+                                          base::Bind(&DumpMemoryProfile),
+                                          base::TimeDelta::FromSeconds(10));
+}
+
 void ChromeBrowserMainPartsLinux::PostMainMessageLoopRun() {
 #if !defined(OS_CHROMEOS)
   // Delete it now. Otherwise the FILE thread would be gone when we try to
   // release it in the dtor and Valgrind would report a leak on almost every
   // single browser_test.
   storage_monitor_.reset();
 #endif
 
+  base::TraceMemoryDump();
+  base::TraceMemoryStop();
+
   ChromeBrowserMainPartsPosix::PostMainMessageLoopRun();
 }