Check in the pristine copy of ICU 51.2

icu51/source/common/umutex.h

Index: icu51/source/common/umutex.h
===================================================================
--- icu51/source/common/umutex.h	(revision 0)
+++ icu51/source/common/umutex.h	(revision 0)
@@ -0,0 +1,229 @@
+/*
+**********************************************************************
+*   Copyright (C) 1997-2012, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*
+* File UMUTEX.H
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   04/02/97  aliu        Creation.
+*   04/07/99  srl         rewrite - C interface, multiple mutices
+*   05/13/99  stephen     Changed to umutex (from cmutex)
+******************************************************************************
+*/
+
+#ifndef UMUTEX_H
+#define UMUTEX_H
+
+#include "unicode/utypes.h"
+#include "unicode/uclean.h"
+#include "putilimp.h"
+
+/* For _ReadWriteBarrier(). */
+#if defined(_MSC_VER) && _MSC_VER >= 1500
+# include <intrin.h>
+#endif
+
+/* For CRITICAL_SECTION */
+#if U_PLATFORM_HAS_WIN32_API
+#if 0  
+/* TODO(andy): Why doesn't windows.h compile in all files? It does in some.
+ *             The intent was to include windows.h here, and have struct UMutex
+ *             have an embedded CRITICAL_SECTION when building on Windows.
+ *             The workaround is to put some char[] storage in UMutex instead,
+ *             avoiding the need to include windows.h everwhere this header is included.
+ */
+# define WIN32_LEAN_AND_MEAN
+# define VC_EXTRALEAN
+# define NOUSER
+# define NOSERVICE
+# define NOIME
+# define NOMCX
+# include <windows.h>
+#endif  /* 0 */
+#define U_WINDOWS_CRIT_SEC_SIZE 64
+#endif  /* win32 */
+
+#if U_PLATFORM_IS_DARWIN_BASED
+#if defined(__STRICT_ANSI__)
+#define UPRV_REMAP_INLINE
+#define inline
+#endif
+#include <libkern/OSAtomic.h>
+#define USE_MAC_OS_ATOMIC_INCREMENT 1
+#if defined(UPRV_REMAP_INLINE)
+#undef inline
+#undef UPRV_REMAP_INLINE
+#endif
+#endif
+
+/*
+ * If we do not compile with dynamic_annotations.h then define
+ * empty annotation macros.
+ *  See http://code.google.com/p/data-race-test/wiki/DynamicAnnotations
+ */
+#ifndef ANNOTATE_HAPPENS_BEFORE
+# define ANNOTATE_HAPPENS_BEFORE(obj)
+# define ANNOTATE_HAPPENS_AFTER(obj)
+# define ANNOTATE_UNPROTECTED_READ(x) (x)
+#endif
+
+#ifndef UMTX_FULL_BARRIER
+# if U_HAVE_GCC_ATOMICS
+#  define UMTX_FULL_BARRIER __sync_synchronize();
+# elif defined(_MSC_VER) && _MSC_VER >= 1500
+    /* From MSVC intrin.h. Use _ReadWriteBarrier() only on MSVC 9 and higher. */
+#  define UMTX_FULL_BARRIER _ReadWriteBarrier();
+# elif U_PLATFORM_IS_DARWIN_BASED
+#  define UMTX_FULL_BARRIER OSMemoryBarrier();
+# else
+#  define UMTX_FULL_BARRIER \
+    { \
+        umtx_lock(NULL); \
+        umtx_unlock(NULL); \
+    }
+# endif
+#endif
+
+#ifndef UMTX_ACQUIRE_BARRIER
+# define UMTX_ACQUIRE_BARRIER UMTX_FULL_BARRIER
+#endif
+
+#ifndef UMTX_RELEASE_BARRIER
+# define UMTX_RELEASE_BARRIER UMTX_FULL_BARRIER
+#endif
+
+/**
+ * \def UMTX_CHECK
+ * Encapsulates a safe check of an expression
+ * for use with double-checked lazy inititialization.
+ * Either memory barriers or mutexes are required, to prevent both the hardware
+ * and the compiler from reordering operations across the check.
+ * The expression must involve only a  _single_ variable, typically
+ *    a possibly null pointer or a boolean that indicates whether some service
+ *    is initialized or not.
+ * The setting of the variable involved in the test must be the last step of
+ *    the initialization process.
+ *
+ * @internal
+ */
+#define UMTX_CHECK(pMutex, expression, result) \
+    { \
+        (result)=(expression); \
+        UMTX_ACQUIRE_BARRIER; \
+    }
+/*
+ * TODO: Replace all uses of UMTX_CHECK and surrounding code
+ * with SimpleSingleton or TriStateSingleton, and remove UMTX_CHECK.
+ */
+
+/*
+ * Code within ICU that accesses shared static or global data should
+ * instantiate a Mutex object while doing so.  The unnamed global mutex
+ * is used throughout ICU, so keep locking short and sweet.
+ *
+ * For example:
+ *
+ * void Function(int arg1, int arg2)
+ * {
+ *   static Object* foo;     // Shared read-write object
+ *   umtx_lock(NULL);        // Lock the ICU global mutex
+ *   foo->Method();
+ *   umtx_unlock(NULL);
+ * }
+ *
+ * an alternative C++ mutex API is defined in the file common/mutex.h
+ */
+
+/*
+ * UMutex - Mutexes for use by ICU implementation code.
+ *          Must be declared as static or globals. They cannot appear as members
+ *          of other objects.
+ *          UMutex structs must be initialized.
+ *          Example:
+ *            static UMutex = U_MUTEX_INITIALIZER;
+ *          The declaration of struct UMutex is platform dependent.
+ */
+
+
+#if U_PLATFORM_HAS_WIN32_API
+
+/*  U_INIT_ONCE mimics the windows API INIT_ONCE, which exists on Windows Vista and newer.
+ *  When ICU no longer needs to support older Windows platforms (XP) that do not have
+ * a native INIT_ONCE, switch this implementation over to wrap the native Windows APIs.
+ */
+typedef struct U_INIT_ONCE {
+    long               fState;
+    void              *fContext;
+} U_INIT_ONCE;
+#define U_INIT_ONCE_STATIC_INIT {0, NULL}
+
+typedef struct UMutex {
+    U_INIT_ONCE       fInitOnce;
+    UMTX              fUserMutex;
+    UBool             fInitialized;  /* Applies to fUserMutex only. */
+    /* CRITICAL_SECTION  fCS; */  /* See note above. Unresolved problems with including
+                                   * Windows.h, which would allow using CRITICAL_SECTION
+                                   * directly here. */
+    char              fCS[U_WINDOWS_CRIT_SEC_SIZE];
+} UMutex;
+
+/* Initializer for a static UMUTEX. Deliberately contains no value for the
+ *  CRITICAL_SECTION.
+ */
+#define U_MUTEX_INITIALIZER {U_INIT_ONCE_STATIC_INIT, NULL, FALSE}
+
+#elif U_PLATFORM_IMPLEMENTS_POSIX
+#include <pthread.h>
+
+struct UMutex {
+    pthread_mutex_t  fMutex;
+    UMTX             fUserMutex;
+    UBool            fInitialized;
+};
+#define U_MUTEX_INITIALIZER  {PTHREAD_MUTEX_INITIALIZER, NULL, FALSE}
+
+#else
+/* Unknow platform type. */
+struct UMutex {
+    void *fMutex;
+};
+#define U_MUTEX_INITIALIZER {NULL}
+#error Unknown Platform.
+
+#endif
+
+#if (U_PLATFORM != U_PF_CYGWIN && U_PLATFORM != U_PF_MINGW) || defined(CYGWINMSVC)
+typedef struct UMutex UMutex;
+#endif
+    
+/* Lock a mutex.
+ * @param mutex The given mutex to be locked.  Pass NULL to specify
+ *              the global ICU mutex.  Recursive locks are an error
+ *              and may cause a deadlock on some platforms.
+ */
+U_CAPI void U_EXPORT2 umtx_lock(UMutex* mutex); 
+
+/* Unlock a mutex.
+ * @param mutex The given mutex to be unlocked.  Pass NULL to specify
+ *              the global ICU mutex.
+ */
+U_CAPI void U_EXPORT2 umtx_unlock (UMutex* mutex);
+
+/*
+ * Atomic Increment and Decrement of an int32_t value.
+ *
+ * Return Values:
+ *   If the result of the operation is zero, the return zero.
+ *   If the result of the operation is not zero, the sign of returned value
+ *      is the same as the sign of the result, but the returned value itself may
+ *      be different from the result of the operation.
+ */
+U_CAPI int32_t U_EXPORT2 umtx_atomic_inc(int32_t *);
+U_CAPI int32_t U_EXPORT2 umtx_atomic_dec(int32_t *);
+
+#endif /*_CMUTEX*/
+/*eof*/
Property changes on: icu51/source/common/umutex.h
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Added: svn:eol-style
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