Fix overflow in timeout logic (open-telemetry#3046)

sdk/src/metrics/export/periodic_exporting_metric_reader.cc

@@ -218,7 +218,7 @@ bool PeriodicExportingMetricReader::OnForceFlush(std::chrono::microseconds timeo
  // - If original `timeout` is `zero`, use that in exporter::forceflush
  // - Else if remaining `timeout_steady` more than zero, use that in exporter::forceflush
  // - Else don't invoke exporter::forceflush ( as remaining time is zero or less)
- if (timeout <= std::chrono::steady_clock::duration::zero())
+ if (timeout <= std::chrono::milliseconds::duration::zero())
  {
  result =
  exporter_->ForceFlush(std::chrono::duration_cast<std::chrono::microseconds>(timeout));

sdk/src/metrics/meter_context.cc

@@ -168,46 +168,36 @@ bool MeterContext::ForceFlush(std::chrono::microseconds timeout) noexcept
  bool result = true;
  // Simultaneous flush not allowed.
  const std::lock_guard<opentelemetry::common::SpinLockMutex> locked(forceflush_lock_);
- // Convert to nanos to prevent overflow
- auto timeout_ns = (std::chrono::nanoseconds::max)();
- if (std::chrono::duration_cast<std::chrono::microseconds>(timeout_ns) > timeout)
- {
- timeout_ns = std::chrono::duration_cast<std::chrono::nanoseconds>(timeout);
- }
-
- auto current_time = std::chrono::system_clock::now();
- std::chrono::system_clock::time_point expire_time;
- auto overflow_checker = (std::chrono::system_clock::time_point::max)();
 
- // check if the expected expire time doesn't overflow.
- if (overflow_checker - current_time > timeout_ns)
+ auto time_remaining = (std::chrono::steady_clock::duration::max)();
+ if (std::chrono::duration_cast<std::chrono::microseconds>(time_remaining) > timeout)
  {
- expire_time =
- current_time + std::chrono::duration_cast<std::chrono::system_clock::duration>(timeout_ns);
+ time_remaining = timeout;
  }
- else
+
+ auto current_time = std::chrono::steady_clock::now();
+ auto expire_time = (std::chrono::steady_clock::time_point::max)();
+ if (expire_time - current_time > time_remaining)
  {
- // overflow happens, reset expire time to max.
- expire_time = overflow_checker;
+ expire_time = current_time + time_remaining;
  }
 
  for (auto &collector : collectors_)
  {
  if (!std::static_pointer_cast<MetricCollector>(collector)->ForceFlush(
- std::chrono::duration_cast<std::chrono::microseconds>(timeout_ns)))
+ std::chrono::duration_cast<std::chrono::microseconds>(time_remaining)))
  {
  result = false;
  }
 
- current_time = std::chrono::system_clock::now();
-
+ current_time = std::chrono::steady_clock::now();
  if (expire_time >= current_time)
  {
- timeout_ns = std::chrono::duration_cast<std::chrono::nanoseconds>(expire_time - current_time);
+ time_remaining = expire_time - current_time;
  }
  else
  {
- timeout_ns = std::chrono::nanoseconds::zero();
+ time_remaining = std::chrono::steady_clock::duration::zero();
  }
  }
  if (!result)