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Re: debug container mutex association
On 20/09/16 09:53 +0100, Jonathan Wakely wrote:
On 19/09/16 21:56 +0200, François Dumont wrote:
Hi
Following our conversation here is a much simpler patch. I just
consider that all debug containers will have the same alignment.
Even if I submit this patch as a whole I will commit into pieces,
at least one for the pure cleanup parts and one for the debug.cc
change.
Among those changes there is:
- __gnu_cxx::__scoped_lock(this->_M_get_mutex());
+ __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
I would appreciate if you could tell me what was happening with
the initial expression. I don't understand why it is compiling. I
even tried the same in debug.cc and started having compilation
errors.
It creates a temporary __scoped_lock, which immediately goes out of
scope and unlocks the mutex again. This should be fixed on the gcc-5
and gcc-6 branches too.
I'm committing this to the gcc-5 and gcc-6 branches.
commit 5218b515fdb54881d8a2b87c28eb5fd84c52db01
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Sep 27 16:22:28 2016 +0100
Fix lifetime of mutex lock in debug iterator
* include/debug/safe_iterator.h (_Safe_iterator::operator++()): Fix
lifetime of lock.
diff --git a/libstdc++-v3/include/debug/safe_iterator.h b/libstdc++-v3/include/debug/safe_iterator.h
index 5368f3b..3f5a7f8 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -296,7 +296,7 @@ namespace __gnu_debug
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
- __gnu_cxx::__scoped_lock(this->_M_get_mutex());
+ __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
++base();
return *this;
}