src/utilities: fix build without pthread

- Remove is_default_thread function which is an internal and not used
  function
- Remove g_main_thread_id as it was used only by is_default_thread

Fixes:
 - http://autobuild.buildroot.net/results/5320bbe1205e782e3516d9bead8d1ed825bcbaad

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

src/utilities.cc

@@ -61,7 +61,6 @@ using std::string;
 _START_GOOGLE_NAMESPACE_
 
 static const char* g_program_invocation_short_name = NULL;
-static pthread_t g_main_thread_id;
 
 _END_GOOGLE_NAMESPACE_
 
@@ -181,16 +180,6 @@ bool IsGoogleLoggingInitialized() {
   return g_program_invocation_short_name != NULL;
 }
 
-bool is_default_thread() {
-  if (g_program_invocation_short_name == NULL) {
-    // InitGoogleLogging() not yet called, so unlikely to be in a different
-    // thread
-    return true;
-  } else {
-    return pthread_equal(pthread_self(), g_main_thread_id);
-  }
-}
-
 #ifdef OS_WINDOWS
 struct timeval {
   long tv_sec, tv_usec;
@@ -276,9 +265,11 @@ pid_t GetTID() {
   return getpid();  // Linux:  getpid returns thread ID when gettid is absent
 #elif defined OS_WINDOWS && !defined OS_CYGWIN
   return GetCurrentThreadId();
-#else
+#elif defined(HAVE_PTHREAD)
   // If none of the techniques above worked, we use pthread_self().
   return (pid_t)(uintptr_t)pthread_self();
+#else
+  return -1;
 #endif
 }
 
@@ -350,7 +341,6 @@ void InitGoogleLoggingUtilities(const char* argv0) {
   if (!slash)  slash = strrchr(argv0, '\\');
 #endif
   g_program_invocation_short_name = slash ? slash + 1 : argv0;
-  g_main_thread_id = pthread_self();
 
 #ifdef HAVE_STACKTRACE
   InstallFailureFunction(&DumpStackTraceAndExit);

src/utilities.h

@@ -163,8 +163,6 @@ const char* ProgramInvocationShortName();
 
 bool IsGoogleLoggingInitialized();
 
-bool is_default_thread();
-
 int64 CycleClock_Now();
 
 int64 UsecToCycles(int64 usec);