Update mutex.h
This change introduces a CriticalSectionLock class as a lightweight replacement for std::mutex on Windows platforms. std::mutex does not work on Windows XP SP2 with the latest VC++ libraries, because it utilizes the Concurrency Runtime that uses ::GetLogicalProcessorInformation which is only supported on Windows XP SP3 and above.
diff --git a/src/google/protobuf/stubs/mutex.h b/src/google/protobuf/stubs/mutex.h
index 8c99736..29bcd21 100644
--- a/src/google/protobuf/stubs/mutex.h
+++ b/src/google/protobuf/stubs/mutex.h
@@ -32,6 +32,17 @@
#include <mutex>
+#ifdef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP
+
+#include <windows.h>
+
+// GetMessage conflicts with GeneratedMessageReflection::GetMessage().
+#ifdef GetMessage
+#undef GetMessage
+#endif
+
+#endif
+
#include <google/protobuf/stubs/macros.h>
// Define thread-safety annotations for use below, if we are building with
@@ -56,6 +67,27 @@
#define GOOGLE_PROTOBUF_LINKER_INITIALIZED
+#ifdef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP
+
+// This class is a lightweight replacement for std::mutex on Windows platforms.
+// std::mutex does not work on Windows XP SP2 with the latest VC++ libraries,
+// because it utilizes the Concurrency Runtime that is only supported on Windows
+// XP SP3 and above.
+class PROTOBUF_EXPORT CriticalSectionLock {
+ public:
+ CriticalSectionLock() { InitializeCriticalSection(&critical_section_); }
+ ~CriticalSectionLock() { DeleteCriticalSection(&critical_section_); }
+ void lock() { EnterCriticalSection(&critical_section_); }
+ void unlock() { LeaveCriticalSection(&critical_section_); }
+
+ private:
+ CRITICAL_SECTION critical_section_;
+
+ GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(CriticalSectionLock);
+};
+
+#endif
+
// Mutex is a natural type to wrap. As both google and other organization have
// specialized mutexes. gRPC also provides an injection mechanism for custom
// mutexes.
@@ -69,7 +101,11 @@
void AssertHeld() const {}
private:
+#ifndef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP
std::mutex mu_;
+#else // ifndef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP
+ CriticalSectionLock mu_;
+#endif // #ifndef GOOGLE_PROTOBUF_SUPPORT_WINDOWS_XP
};
using Mutex = WrappedMutex;
