chrome/browser/metrics/thread_watcher_report_hang.cc

// Copyright 2014 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/metrics/thread_watcher_report_hang.h"

#include "base/debug/activity_tracker.h"
#include "base/debug/debugger.h"
#include "base/debug/dump_without_crashing.h"
#include "base/time/time.h"
#include "build/build_config.h"

namespace metrics {

// The following are unique function names for forcing the crash when a thread
// is unresponsive. This makes it possible to tell from the callstack alone what
// thread was unresponsive. Inhibiting tail calls to this function ensures that
// the caller will appear on the call stack.
NOINLINE NOT_TAIL_CALLED void ReportThreadHang() {
  [[maybe_unused]] volatile const char* inhibit_comdat = __func__;

  // The first 8 characters of sha1 of "ReportThreadHang".
  // echo -n "ReportThreadHang" | sha1sum
  static constexpr uint32_t kActivityTrackerId = 0xceec103d;

  base::debug::ScopedActivity scoped_activity(0, kActivityTrackerId, 0);
  auto& user_data = scoped_activity.user_data();
  const base::TimeTicks now = base::TimeTicks::Now();
  user_data.SetUint("timestamp_us", now.since_origin().InMicroseconds());

#if defined(NDEBUG)
  base::debug::DumpWithoutCrashing();
#else
  base::debug::BreakDebugger();
#endif
}

#if !BUILDFLAG(IS_ANDROID)

NOINLINE void StartupHang() {
  // TODO(rtenneti): http://crbug.com/440885 enable crashing after fixing false
  // positive startup hang data.
  // ReportThreadHang();
  [[maybe_unused]] volatile int inhibit_comdat = __LINE__;
}

NOINLINE void ShutdownHang() {
  ReportThreadHang();
  [[maybe_unused]] volatile int inhibit_comdat = __LINE__;
}

#endif  // !BUILDFLAG(IS_ANDROID)

NOINLINE void ThreadUnresponsive_UI() {
  ReportThreadHang();
  [[maybe_unused]] volatile int inhibit_comdat = __LINE__;
}

NOINLINE void ThreadUnresponsive_IO() {
  ReportThreadHang();
  [[maybe_unused]] volatile int inhibit_comdat = __LINE__;
}

NOINLINE void CrashBecauseThreadWasUnresponsive(
    content::BrowserThread::ID thread_id) {
  switch (thread_id) {
    case content::BrowserThread::UI:
      return ThreadUnresponsive_UI();
    case content::BrowserThread::IO:
      return ThreadUnresponsive_IO();
    case content::BrowserThread::ID_COUNT:
      NOTREACHED();
      break;
  }
}

}  // namespace metrics