namespace simgrid {
namespace simix {
+/** Fulfill a promise by executing a given code */
template<class R, class F>
void fulfill_promise(std::promise<R>& promise, F&& code)
{
try {
- promise.set_value(code());
+ promise.set_value(std::forward<F>(code)());
}
catch(...) {
promise.set_exception(std::current_exception());
}
}
-// special version for R=void because the previous code does not compile
-// in this case:
+/** Fulfill a promise by executing a given code
+ *
+ * This is a special version for `std::promise<void>` because the default
+ * version does not compile in this case.
+ */
template<class F>
void fulfill_promise(std::promise<void>& promise, F&& code)
{
try {
- code();
+ std::forward<F>(code)();
promise.set_value();
}
catch(...) {
}
}
+/** Execute some code in the kernel/maestro
+ *
+ * This can be used to enforce mutual exclusion with other simcall.
+ * More importantly, this enforces a deterministic/reproducible ordering
+ * of the operation with respect to other simcalls.
+ */
template<class F>
typename std::result_of<F()>::type kernel(F&& code)
{
+ // If we are in the maestro, we take the fast path and execute the
+ // code directly without simcall mashalling/unmarshalling/dispatch:
+ if (SIMIX_is_maestro())
+ return std::forward<F>(code)();
+
+ // If we are in the application, pass the code to the maestro which is
+ // executes it for us and reports the result. We use a std::future which
+ // conveniently handles the success/failure value for us.
typedef typename std::result_of<F()>::type R;
std::promise<R> promise;
simcall_run_kernel([&]{
- fulfill_promise(promise, code);
+ xbt_assert(SIMIX_is_maestro(), "Not in maestro");
+ fulfill_promise(promise, std::forward<F>(code));
});
return promise.get_future().get();
}
