src/glog/logging.h.in: fix race conditions in LOG_EVERY_N

src/glog/logging.h.in

@@ -86,6 +86,22 @@
 #include <gflags/gflags.h>
 #endif
 
+// Check if it's compiled in C++11 mode.
+//
+// GXX_EXPERIMENTAL_CXX0X is defined by gcc and clang up to at least
+// gcc-4.7 and clang-3.1 (2011-12-13).  __cplusplus was defined to 1
+// in gcc before 4.7 (Crosstool 16) and clang before 3.1, but is
+// defined according to the language version in effect thereafter.
+// Microsoft Visual Studio 14 (2015) sets __cplusplus==199711 despite
+// reasonably good C++11 support, so we set LANG_CXX for it and
+// newer versions (_MSC_VER >= 1900).
+#define SUPPORT_CPLUSPLUS11 (defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L || \
+                            (defined(_MSC_VER) && _MSC_VER >= 1900)) && !defined(__UCLIBCXX_MAJOR__)
+
+#if SUPPORT_CPLUSPLUS11
+#include <atomic>
+#endif
+
 @ac_google_start_namespace@
 
 #if @ac_cv_have_uint16_t@      // the C99 format
@@ -896,6 +912,45 @@ PLOG_IF(FATAL, GOOGLE_PREDICT_BRANCH_NOT_TAKEN((invocation) == -1))    \
 #define LOG_OCCURRENCES LOG_EVERY_N_VARNAME(occurrences_, __LINE__)
 #define LOG_OCCURRENCES_MOD_N LOG_EVERY_N_VARNAME(occurrences_mod_n_, __LINE__)
 
+#if SUPPORT_CPLUSPLUS11
+#define SOME_KIND_OF_LOG_EVERY_N(severity, n, what_to_do) \
+  static std::atomic<int> LOG_OCCURRENCES(0), LOG_OCCURRENCES_MOD_N(0); \
+  ++LOG_OCCURRENCES; \
+  if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
+  if (LOG_OCCURRENCES_MOD_N == 1) \
+    @ac_google_namespace@::LogMessage( \
+        __FILE__, __LINE__, @ac_google_namespace@::GLOG_ ## severity, LOG_OCCURRENCES, \
+        &what_to_do).stream()
+
+#define SOME_KIND_OF_LOG_IF_EVERY_N(severity, condition, n, what_to_do) \
+  static std::atomic<int> LOG_OCCURRENCES(0), LOG_OCCURRENCES_MOD_N(0); \
+  ++LOG_OCCURRENCES; \
+  if (condition && \
+      ((LOG_OCCURRENCES_MOD_N=(LOG_OCCURRENCES_MOD_N + 1) % n) == (1 % n))) \
+    @ac_google_namespace@::LogMessage( \
+        __FILE__, __LINE__, @ac_google_namespace@::GLOG_ ## severity, LOG_OCCURRENCES, \
+                 &what_to_do).stream()
+
+#define SOME_KIND_OF_PLOG_EVERY_N(severity, n, what_to_do) \
+  static std::atomic<int> LOG_OCCURRENCES(0), LOG_OCCURRENCES_MOD_N(0); \
+  ++LOG_OCCURRENCES; \
+  if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
+  if (LOG_OCCURRENCES_MOD_N == 1) \
+    @ac_google_namespace@::ErrnoLogMessage( \
+        __FILE__, __LINE__, @ac_google_namespace@::GLOG_ ## severity, LOG_OCCURRENCES, \
+        &what_to_do).stream()
+
+#define SOME_KIND_OF_LOG_FIRST_N(severity, n, what_to_do) \
+  static std::atomic<int> LOG_OCCURRENCES(0); \
+  if (LOG_OCCURRENCES <= n) \
+    ++LOG_OCCURRENCES; \
+  if (LOG_OCCURRENCES <= n) \
+    @ac_google_namespace@::LogMessage( \
+        __FILE__, __LINE__, @ac_google_namespace@::GLOG_ ## severity, LOG_OCCURRENCES, \
+        &what_to_do).stream()
+
+#else
+
 #define SOME_KIND_OF_LOG_EVERY_N(severity, n, what_to_do) \
   static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
   ++LOG_OCCURRENCES; \
@@ -931,6 +986,7 @@ PLOG_IF(FATAL, GOOGLE_PREDICT_BRANCH_NOT_TAKEN((invocation) == -1))    \
     @ac_google_namespace@::LogMessage( \
         __FILE__, __LINE__, @ac_google_namespace@::GLOG_ ## severity, LOG_OCCURRENCES, \
         &what_to_do).stream()
+#endif
 
 namespace glog_internal_namespace_ {
 template <bool>
@@ -1315,17 +1371,7 @@ inline void LogAtLevel(int const severity, std::string const &msg) {
 // LOG macros, 2. this macro can be used as C++ stream.
 #define LOG_AT_LEVEL(severity) @ac_google_namespace@::LogMessage(__FILE__, __LINE__, severity).stream()
 
-// Check if it's compiled in C++11 mode.
-//
-// GXX_EXPERIMENTAL_CXX0X is defined by gcc and clang up to at least
-// gcc-4.7 and clang-3.1 (2011-12-13).  __cplusplus was defined to 1
-// in gcc before 4.7 (Crosstool 16) and clang before 3.1, but is
-// defined according to the language version in effect thereafter.
-// Microsoft Visual Studio 14 (2015) sets __cplusplus==199711 despite
-// reasonably good C++11 support, so we set LANG_CXX for it and
-// newer versions (_MSC_VER >= 1900).
-#if (defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L || \
-     (defined(_MSC_VER) && _MSC_VER >= 1900)) && !defined(__UCLIBCXX_MAJOR__)
+#if SUPPORT_CPLUSPLUS11
 // Helper for CHECK_NOTNULL().
 //
 // In C++11, all cases can be handled by a single function. Since the value