--- /dev/null
+//========================================================================
+//
+// GMutex.h
+//
+// Portable mutex macros.
+//
+// Copyright 2002 Glyph & Cog, LLC
+//
+//========================================================================
+
+#ifndef GMUTEX_H
+#define GMUTEX_H
+
+// Usage:
+//
+// GMutex m;
+// gInitMutex(&m);
+// ...
+// gLockMutex(&m);
+// ... critical section ...
+// gUnlockMutex(&m);
+// ...
+// gDestroyMutex(&m);
+
+#ifdef WIN32
+
+#include <windows.h>
+
+typedef CRITICAL_SECTION GMutex;
+
+#define gInitMutex(m) InitializeCriticalSection(m)
+#define gDestroyMutex(m) DeleteCriticalSection(m)
+#define gLockMutex(m) EnterCriticalSection(m)
+#define gUnlockMutex(m) LeaveCriticalSection(m)
+
+#else // assume pthreads
+
+#include <pthread.h>
+
+typedef pthread_mutex_t GMutex;
+
+#define gInitMutex(m) pthread_mutex_init(m, NULL)
+#define gDestroyMutex(m) pthread_mutex_destroy(m)
+#define gLockMutex(m) pthread_mutex_lock(m)
+#define gUnlockMutex(m) pthread_mutex_unlock(m)
+
+#endif
+
+#endif