[syncd] Bring back TimerWatchdog (#821)

syncd/Syncd.cpp

@@ -14,6 +14,7 @@
 #include "RedisSelectableChannel.h"
 #include "ZeroMQSelectableChannel.h"
 #include "PerformanceIntervalTimer.h"
+#include "TimerWatchdog.h"
 
 #include "sairediscommon.h"
 
@@ -4295,6 +4296,14 @@ bool Syncd::isVeryFirstRun()
  return firstRun;
 }
 
+static void timerWatchdogCallback(
+ _In_ int64_t span)
+{
+ SWSS_LOG_ENTER();
+
+ SWSS_LOG_ERROR("main loop execution exceeded %ld us", span);
+}
+
 void Syncd::run()
 {
  SWSS_LOG_ENTER();
@@ -4342,6 +4351,10 @@ void Syncd::run()
  runMainLoop = false;
  }
 
+ TimerWatchdog twd(30 * 1000000); // watch for executions over 30 seconds
+
+ twd.setCallback(timerWatchdogCallback);
+
  while(runMainLoop)
  {
  try
@@ -4350,6 +4363,8 @@ void Syncd::run()
 
  int result = s->select(&sel);
 
+ twd.setStartTime();
+
  if (sel == m_restartQuery.get())
  {
  /*
@@ -4438,6 +4453,8 @@ void Syncd::run()
  {
  SWSS_LOG_ERROR("select failed: %d", result);
  }
+
+ twd.setEndTime();
  }
  catch(const std::exception &e)
  {
@@ -4454,6 +4471,8 @@ void Syncd::run()
 
  // make sure that if second exception will arise, then we break the loop
  m_commandLineOptions->m_disableExitSleep = true;
+
+ twd.setEndTime();
  }
  }