Record Chrome trace events in tcmalloc heap profiles

chrome/browser/chrome_browser_main_linux.cc

Index: chrome/browser/chrome_browser_main_linux.cc
diff --git a/chrome/browser/chrome_browser_main_linux.cc b/chrome/browser/chrome_browser_main_linux.cc
index 870a95c53670669280fffd38d6492facb7d74dff..2c46b56f4582e02b1275bc9a2471fbfc89dd5339 100644
--- a/chrome/browser/chrome_browser_main_linux.cc
+++ b/chrome/browser/chrome_browser_main_linux.cc
@@ -4,6 +4,8 @@
 
 #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"
@@ -101,6 +103,45 @@ bool IsCrashReportingEnabled(const PrefService* local_state) {
 }
 #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(
@@ -141,6 +182,19 @@ void ChromeBrowserMainPartsLinux::PostProfileInit() {
   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
@@ -149,5 +203,8 @@ void ChromeBrowserMainPartsLinux::PostMainMessageLoopRun() {
   storage_monitor_.reset();
 #endif
 
+  base::TraceMemoryDump();
+  base::TraceMemoryStop();
+
   ChromeBrowserMainPartsPosix::PostMainMessageLoopRun();
 }