On 2005-04-15, at 01:10, Richard Henderson wrote:
On Thu, Apr 14, 2005 at 11:30:20PM +0200, Jason Merrill wrote:
Consider Double-Checked Locking
(http://www.cs.umd.edu/~pugh/java/memoryModel/
DoubleCheckedLocking.html).
I used DCL with explicit memory barriers to implement thread-safe
initialization of function-local statics
(libstdc++-v3/libsupc++/guard.cc). The proposed change to volatile
semantics would allow me to write it more simply, by just making the
initialized flag volatile. Yes, volatile would be stronger than is
actually necessary for DCLP, but I don't have to use it if I want
finer-grained control over the synchronization.
Is there any reason to want to overload volatile for this, rather than
template<classname T> T acquire(T *ptr);
template<classname T> void release(T *ptr, T val);
where the functions do the indirection plus the memory ordering?
Templates are a no-go for a well known and well defined subset for C++
for embedded programming known commonly as well embedded C++.
Actually speaking about embedded C++. Well, it would be helpful
to have an option for the C++ frontend which would disallow
constructs prohibited by it. If I only could find the time right now...
