Making use of GetSystemTimePreciseAsFileTime dynamic - code review fixes

db/auto_roll_logger.cc

@@ -32,9 +32,11 @@ Status AutoRollLogger::ResetLogger() {
 }
 
 void AutoRollLogger::RollLogFile() {
+  // This function is called when log is rotating. Two rotations
+  // can happen quickly (NowMicro returns same value). To not overwrite
+  // previous log file we increment by one micro second and try again.
   uint64_t now = env_->NowMicros();
   std::string old_fname;
-  // Try to check target name only 10 times at most
   for (int i = 0; i < 10; i++) {
     old_fname = OldInfoLogFileName(
       dbname_, now, db_absolute_path_, db_log_dir_);

port/win/env_win.cc

@@ -2110,29 +2110,23 @@ class WinEnv : public Env {
   std::vector<ThreadPool> thread_pools_;
   mutable std::mutex mu_;
   std::vector<std::thread> threads_to_join_;
-  static FnGetSystemTimePreciseAsFileTime GetSystemTimePreciseAsFileTime_;
-  static bool GetSystemTimePreciseAsFileTimeInitialized_;
+  FnGetSystemTimePreciseAsFileTime GetSystemTimePreciseAsFileTime_;
 };
 
-FnGetSystemTimePreciseAsFileTime WinEnv::GetSystemTimePreciseAsFileTime_ = NULL;
-bool WinEnv::GetSystemTimePreciseAsFileTimeInitialized_ = false;
-
 WinEnv::WinEnv()
     : checkedDiskForMmap_(false),
       forceMmapOff(false),
       page_size_(4 * 1012),
       allocation_granularity_(page_size_),
       perf_counter_frequency_(0),
-      thread_pools_(Priority::TOTAL) {
+      thread_pools_(Priority::TOTAL),
+      GetSystemTimePreciseAsFileTime_(NULL) {
 
-  if (!GetSystemTimePreciseAsFileTimeInitialized_) {
   HMODULE module = GetModuleHandle("kernel32.dll");
   if (module != NULL) {
     GetSystemTimePreciseAsFileTime_ = (FnGetSystemTimePreciseAsFileTime)GetProcAddress(
       module, "GetSystemTimePreciseAsFileTime");
   }
-    GetSystemTimePreciseAsFileTimeInitialized_ = true;
-  }
 
   SYSTEM_INFO sinfo;
   GetSystemInfo(&sinfo);