[PATCH] More noexcept for standard mutex types and locks

[Jonathan Wakely]

These functions can all be noexcept (if we ever wanted to check the
mutex is owned by the calling thread in the adopt_lock ctors we'd
abort, not throw).

        * include/bits/std_mutex.h (mutex::native_handle)
        (lock_guard(mutex_type&, adopt_lock_t)
        (unique_lock(mutex_type&, adopt_lock_t): Add noexcept.
        * include/std/mutex (recursive_mutex, timed_mutex)
        (recursive_timed_mutex): Likewise.

Tested powerpc64le-linux, committed to trunk.


commit 65e13b82ae0dac570b2e558d302bffa791d94375
Author: redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Tue Oct 11 10:33:16 2016 +0000

    More noexcept for standard mutex types and locks
    
        * include/bits/std_mutex.h (mutex::native_handle)
        (lock_guard(mutex_type&, adopt_lock_t)
        (unique_lock(mutex_type&, adopt_lock_t): Add noexcept.
        * include/std/mutex (recursive_mutex, timed_mutex)
        (recursive_timed_mutex): Likewise.
    
    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@240980 
138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/include/bits/std_mutex.h 
b/libstdc++-v3/include/bits/std_mutex.h
index 49ef752..ad43841 100644
--- a/libstdc++-v3/include/bits/std_mutex.h
+++ b/libstdc++-v3/include/bits/std_mutex.h
@@ -122,7 +122,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     native_handle_type
-    native_handle()
+    native_handle() noexcept
     { return &_M_mutex; }
   };
 
@@ -161,7 +161,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       explicit lock_guard(mutex_type& __m) : _M_device(__m)
       { _M_device.lock(); }
 
-      lock_guard(mutex_type& __m, adopt_lock_t) : _M_device(__m)
+      lock_guard(mutex_type& __m, adopt_lock_t) noexcept : _M_device(__m)
       { } // calling thread owns mutex
 
       ~lock_guard()
@@ -206,7 +206,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       : _M_device(std::__addressof(__m)), _M_owns(_M_device->try_lock())
       { }
 
-      unique_lock(mutex_type& __m, adopt_lock_t)
+      unique_lock(mutex_type& __m, adopt_lock_t) noexcept
       : _M_device(std::__addressof(__m)), _M_owns(true)
       {
        // XXX calling thread owns mutex
diff --git a/libstdc++-v3/include/std/mutex b/libstdc++-v3/include/std/mutex
index 1f4da57..7a7bd2e 100644
--- a/libstdc++-v3/include/std/mutex
+++ b/libstdc++-v3/include/std/mutex
@@ -124,7 +124,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     native_handle_type
-    native_handle()
+    native_handle() noexcept
     { return &_M_mutex; }
   };
 
@@ -219,7 +219,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     native_handle_type
-    native_handle()
+    native_handle() noexcept
     { return &_M_mutex; }
 
     private:
@@ -279,7 +279,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
     native_handle_type
-    native_handle()
+    native_handle() noexcept
     { return &_M_mutex; }
 
     private: