GLog.h File Reference

#include <atomic>
#include <chrono>
#include <glog/logging.h>

Go to the source code of this file.

Macros
#define	FB_LOG_EVERY_MS(severity, milli_interval)

Macro Definition Documentation

#define FB_LOG_EVERY_MS	(		severity,
			milli_interval
	)

Value:

for (decltype(milli_interval) FB_LEM_once = 1,                               \
                                FB_LEM_interval = (milli_interval);            \
       FB_LEM_once;)                                                           \
    for (::std::chrono::milliseconds::rep FB_LEM_prev,                         \
         FB_LEM_now = FB_LEM_interval <= 0                                     \
             ? 0                                                               \
             : ::std::chrono::duration_cast<::std::chrono::milliseconds>(      \
                   ::std::chrono::system_clock::now().time_since_epoch())      \
                   .count();                                                   \
         FB_LEM_once;)                                                         \
      for (static ::std::atomic<::std::chrono::milliseconds::rep> FB_LEM_hist; \
           FB_LEM_once;                                                        \
           FB_LEM_once = 0)                                                    \
        if (FB_LEM_interval > 0 &&                                             \
            (FB_LEM_now -                                                      \
                     (FB_LEM_prev =                                            \
                          FB_LEM_hist.load(std::memory_order_acquire)) <       \
                 FB_LEM_interval ||                                            \
             !FB_LEM_hist.compare_exchange_strong(FB_LEM_prev, FB_LEM_now))) { \
        } else                                                                 \
          LOG(severity)

Issues a LOG(severity) no more often than every milliseconds. Example:

FB_LOG_EVERY_MS(INFO, 10000) << "At least ten seconds passed" " since you last saw this.";

The implementation uses for statements to introduce variables in a nice way that doesn't mess surrounding statements. It is thread safe. Non-positive intervals will always log.

Definition at line 36 of file GLog.h.

Referenced by BENCHMARK(), folly::detail::MemoryIdler::flushLocalMallocCaches(), and TEST().