go back to ps #4

patches/mutex.patch

+diff --git a/source/common/putilimp.h b/source/common/putilimp.h
+index e3da340..90bae92 100644
+--- a/source/common/putilimp.h
++++ b/source/common/putilimp.h
+@@ -1,7 +1,7 @@
+ /*
+ ******************************************************************************
+ *
+-*   Copyright (C) 1997-2014, International Business Machines
++*   Copyright (C) 1997-2015, International Business Machines
+ *   Corporation and others.  All Rights Reserved.
+ *
+ ******************************************************************************
+@@ -229,6 +229,26 @@ typedef size_t uintptr_t;
+ #endif
+ 
+ 
++/**
++ *  \def U_HAVE_CLANG_ATOMICS
++ *  Defines whether Clang c11 style built-in atomics are avaialable.
++ *  These are used in preference to gcc atomics when both are available.
++ */
++#ifdef U_HAVE_CLANG_ATOMICS
++    /* Use the predefined value. */
++#elif !defined(__clang__)
++#    define U_HAVE_CLANG_ATOMICS 0
++#else
++#if __has_builtin(__c11_atomic_load) && \
++    __has_builtin(__c11_atomic_store) && \
++    __has_builtin(__c11_atomic_fetch_add) && \
++    __has_builtin(__c11_atomic_fetch_sub)
++#    define U_HAVE_CLANG_ATOMICS 1
++#else
++#    define U_HAVE_CLANG_ATOMICS 0
++#endif
++#endif
++
+ /*===========================================================================*/
+ /** @{ Code alignment                                                        */
+ /*===========================================================================*/
+diff --git a/source/common/umutex.cpp b/source/common/umutex.cpp
+index 0c1fdc8..581f2b9 100644
+--- a/source/common/umutex.cpp
++++ b/source/common/umutex.cpp
+@@ -349,8 +349,8 @@ umtx_atomic_dec(u_atomic_int32_t *p) {
+ 
+ U_COMMON_API int32_t U_EXPORT2
+ umtx_loadAcquire(u_atomic_int32_t &var) {
+-    int32_t val = var;
+     umtx_lock(&gIncDecMutex);
++    int32_t val = var;
+     umtx_unlock(&gIncDecMutex);
+     return val;
+ }
+@@ -358,8 +358,8 @@ umtx_loadAcquire(u_atomic_int32_t &var) {
+ U_COMMON_API void U_EXPORT2
+ umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
+     umtx_lock(&gIncDecMutex);
+-    umtx_unlock(&gIncDecMutex);
+     var = val;
++    umtx_unlock(&gIncDecMutex);
+ }
+ 
+ U_NAMESPACE_END
+diff --git a/source/common/umutex.h b/source/common/umutex.h
+index e0ad0d3..0e4d118 100644
+--- a/source/common/umutex.h
++++ b/source/common/umutex.h
+@@ -1,6 +1,6 @@
+ /*
+ **********************************************************************
+-*   Copyright (C) 1997-2014, International Business Machines
++*   Copyright (C) 1997-2015, International Business Machines
+ *   Corporation and others.  All Rights Reserved.
+ **********************************************************************
+ *
+@@ -118,6 +118,33 @@ inline int32_t umtx_atomic_dec(u_atomic_int32_t *var) {
+ U_NAMESPACE_END
+ 
+ 
++#elif U_HAVE_CLANG_ATOMICS
++/*
++ *  Clang __c11 atomic built-ins
++ */
++
++U_NAMESPACE_BEGIN
++typedef _Atomic(int32_t) u_atomic_int32_t;
++#define ATOMIC_INT32_T_INITIALIZER(val) val
++
++inline int32_t umtx_loadAcquire(u_atomic_int32_t &var) {
++     return __c11_atomic_load(&var, __ATOMIC_ACQUIRE);
++}
++
++inline void umtx_storeRelease(u_atomic_int32_t &var, int32_t val) {
++   return __c11_atomic_store(&var, val, __ATOMIC_RELEASE);
++}
++
++inline int32_t umtx_atomic_inc(u_atomic_int32_t *var) {
++    return __c11_atomic_fetch_add(var, 1, __ATOMIC_SEQ_CST) + 1;
++}
++
++inline int32_t umtx_atomic_dec(u_atomic_int32_t *var) {
++    return __c11_atomic_fetch_sub(var, 1, __ATOMIC_SEQ_CST) - 1;
++}
++U_NAMESPACE_END
++
++
+ #elif U_HAVE_GCC_ATOMICS
+ /*
+  * gcc atomic ops. These are available on several other compilers as well.