[base] Use thread safe localtime_r() instead of localtime().

src/base/platform/platform-cygwin.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Platform-specific code for Cygwin goes here. For the POSIX-compatible
 // parts, the implementation is in platform-posix.cc.
 
 #include <errno.h>
 #include <pthread.h>
 #include <semaphore.h>
@@ skipping 11 matching lines @@
 #include "src/base/platform/platform.h"
 #include "src/base/win32-headers.h"
 
 namespace v8 {
 namespace base {
 
 
 const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
-  struct tm* t = localtime(&tv);  // NOLINT(runtime/threadsafe_fn)
+  struct tm tm;
+  struct tm* t = localtime_r(&tv, &tm);
   if (NULL == t) return "";
   return tzname[0];  // The location of the timezone string on Cygwin.
 }
 
 
 double OS::LocalTimeOffset(TimezoneCache* cache) {
   // On Cygwin, struct tm does not contain a tm_gmtoff field.
   time_t utc = time(NULL);
   DCHECK(utc != -1);
-  struct tm* loc = localtime(&utc);  // NOLINT(runtime/threadsafe_fn)
+  struct tm tm;
+  struct tm* loc = localtime_r(&utc, &tm);
   DCHECK(loc != NULL);
   // time - localtime includes any daylight savings offset, so subtract it.
   return static_cast<double>((mktime(loc) - utc) * msPerSecond -
                              (loc->tm_isdst > 0 ? 3600 * msPerSecond : 0));
 }
 
 
 void* OS::Allocate(const size_t requested,
                    size_t* allocated,
                    bool is_executable) {
@@ skipping 194 matching lines @@
 }
 
 
 bool VirtualMemory::HasLazyCommits() {
   // TODO(alph): implement for the platform.
   return false;
 }
 
 }  // namespace base
 }  // namespace v8