C++ (Cpp) SharedLibraryInfo::Clear Examples

Example #1

File: HangMonitor.cpp Project: mozilla/pjs

static void
GetChromeHangReport(Telemetry::HangStack &callStack, SharedLibraryInfo &moduleMap)
{
  MOZ_ASSERT(winMainThreadHandle);

  DWORD ret = ::SuspendThread(winMainThreadHandle);
  if (ret == -1) {
    callStack.Clear();
    moduleMap.Clear();
    return;
  }
  NS_StackWalk(ChromeStackWalker, 0, &callStack,
               reinterpret_cast<uintptr_t>(winMainThreadHandle));
  ret = ::ResumeThread(winMainThreadHandle);
  if (ret == -1) {
    callStack.Clear();
    moduleMap.Clear();
    return;
  }

  moduleMap = SharedLibraryInfo::GetInfoForSelf();
  moduleMap.SortByAddress();

  // Remove all modules not referenced by a PC on the stack
  Telemetry::HangStack sortedStack = callStack;
  sortedStack.Sort();

  size_t moduleIndex = 0;
  size_t stackIndex = 0;
  bool unreferencedModule = true;
  while (stackIndex < sortedStack.Length() && moduleIndex < moduleMap.GetSize()) {
    uintptr_t pc = sortedStack[stackIndex];
    SharedLibrary& module = moduleMap.GetEntry(moduleIndex);
    uintptr_t moduleStart = module.GetStart();
    uintptr_t moduleEnd = module.GetEnd() - 1;
    if (moduleStart <= pc && pc <= moduleEnd) {
      // If the current PC is within the current module, mark module as used
      unreferencedModule = false;
      ++stackIndex;
    } else if (pc > moduleEnd) {
      if (unreferencedModule) {
        // Remove module if no PCs within its address range
        moduleMap.RemoveEntries(moduleIndex, moduleIndex + 1);
      } else {
        // Module was referenced on stack, but current PC belongs to later module
        unreferencedModule = true;
        ++moduleIndex;
      }
    } else {
      // PC does not belong to any module
      ++stackIndex;
    }
  }

  // Clean up remaining unreferenced modules, i.e. module addresses > max(pc)
  if (moduleIndex + 1 < moduleMap.GetSize()) {
    moduleMap.RemoveEntries(moduleIndex + 1, moduleMap.GetSize());
  }
}

Example #2

File: HangMonitor.cpp Project: mozilla/pjs

void
ThreadMain(void*)
{
  PR_SetCurrentThreadName("Hang Monitor");

  MonitorAutoLock lock(*gMonitor);

  // In order to avoid issues with the hang monitor incorrectly triggering
  // during a general system stop such as sleeping, the monitor thread must
  // run twice to trigger hang protection.
  PRIntervalTime lastTimestamp = 0;
  int waitCount = 0;

#ifdef REPORT_CHROME_HANGS
  Telemetry::HangStack hangStack;
  SharedLibraryInfo hangModuleMap;
#endif

  while (true) {
    if (gShutdown) {
      return; // Exit the thread
    }

    // avoid rereading the volatile value in this loop
    PRIntervalTime timestamp = gTimestamp;

    PRIntervalTime now = PR_IntervalNow();

    if (timestamp != PR_INTERVAL_NO_WAIT &&
        now < timestamp) {
      // 32-bit overflow, reset for another waiting period
      timestamp = 1; // lowest legal PRInterval value
    }

    if (timestamp != PR_INTERVAL_NO_WAIT &&
        timestamp == lastTimestamp &&
        gTimeout > 0) {
      ++waitCount;
      if (waitCount == 2) {
#ifdef REPORT_CHROME_HANGS
        GetChromeHangReport(hangStack, hangModuleMap);
#else
        PRInt32 delay =
          PRInt32(PR_IntervalToSeconds(now - timestamp));
        if (delay > gTimeout) {
          MonitorAutoUnlock unlock(*gMonitor);
          Crash();
        }
#endif
      }
    }
    else {
#ifdef REPORT_CHROME_HANGS
      if (waitCount >= 2) {
        PRUint32 hangDuration = PR_IntervalToSeconds(now - lastTimestamp);
        Telemetry::RecordChromeHang(hangDuration, hangStack, hangModuleMap);
        hangStack.Clear();
        hangModuleMap.Clear();
      }
#endif
      lastTimestamp = timestamp;
      waitCount = 0;
    }

    PRIntervalTime timeout;
    if (gTimeout <= 0) {
      timeout = PR_INTERVAL_NO_TIMEOUT;
    }
    else {
      timeout = PR_MillisecondsToInterval(gTimeout * 500);
    }
    lock.Wait(timeout);
  }
}