X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/53ce86d0b99163e9f523ef8f994854474d297328..a707ad979be7c88d7581f403661c67598d320d55:/include/simgrid/simix.hpp

diff --git a/include/simgrid/simix.hpp b/include/simgrid/simix.hpp
index 7cabe4f7e6..fb8addfb3c 100644
--- a/include/simgrid/simix.hpp
+++ b/include/simgrid/simix.hpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2007-2019. The SimGrid Team.
+/* Copyright (c) 2007-2022. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -7,92 +7,92 @@
 #ifndef SIMGRID_SIMIX_HPP
 #define SIMGRID_SIMIX_HPP
 
-#include <simgrid/simix.h>
-#include <xbt/functional.hpp>
-#include <xbt/future.hpp>
+#include <simgrid/s4u/Actor.hpp>
+#include <xbt/promise.hpp>
 #include <xbt/signal.hpp>
 
 #include <string>
 #include <unordered_map>
 
-XBT_PUBLIC void simcall_run_kernel(std::function<void()> const& code);
-
-/** Execute some code in the kernel and block
- *
- * run_blocking() is a generic blocking simcall. It is given a callback
- * which is executed immediately in the SimGrid kernel. The callback is
- * responsible for setting the suitable logic for waking up the process
- * when needed.
- *
- * @ref simix::kernelSync() is a higher level wrapper for this.
- */
-XBT_PUBLIC void simcall_run_blocking(std::function<void()> const& code);
-
-template<class F> inline
-void simcall_run_kernel(F& f)
-{
-  simcall_run_kernel(std::function<void()>(std::ref(f)));
-}
-template<class F> inline
-void simcall_run_blocking(F& f)
-{
-  simcall_run_blocking(std::function<void()>(std::ref(f)));
-}
+XBT_PUBLIC void simcall_run_answered(std::function<void()> const& code,
+                                     simgrid::kernel::actor::SimcallObserver* observer);
+XBT_PUBLIC void simcall_run_blocking(std::function<void()> const& code,
+                                     simgrid::kernel::actor::SimcallObserver* observer);
 
 namespace simgrid {
+namespace kernel {
+namespace actor {
 
-namespace simix {
-
-/** Execute some code in the kernel/maestro
+/** Execute some code in kernel context on behalf of the user code.
+ *
+ * Every modification of the environment must be protected this way: every setter, constructor and similar.
+ * Getters don't have to be protected this way.
  *
- *  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.
+ * This allows deterministic parallel simulation without any locking, even if almost nobody uses parallel simulation in
+ * SimGrid. More interestingly it makes every modification of the simulated world observable by the model-checker,
+ * allowing the whole MC business.
+ *
+ * It is highly inspired from the syscalls in a regular operating system, allowing the user code to get some specific
+ * code executed in the kernel context. But here, there is almost no security involved. Parameters get checked for
+ * finiteness but that's all. The main goal remain to ensure reproducible ordering of uncomparable events (in
+ * [parallel] simulation) and observability of events (in model-checking).
+ *
+ * The code passed as argument is supposed to terminate at the exact same simulated timestamp.
+ * Do not use it if your code may block waiting for a subsequent event, e.g. if you lock a mutex,
+ * you may need to wait for that mutex to be unlocked by its current owner.
+ * Potentially blocking simcall must be issued using simcall_blocking(), right below in this file.
  */
-template <class F> typename std::result_of<F()>::type simcall(F&& code)
+template <class F> typename std::result_of_t<F()> simcall_answered(F&& code, SimcallObserver* observer = nullptr)
 {
   // 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())
+  // code directly without simcall marshalling/unmarshalling/dispatch:
+  if (s4u::Actor::is_maestro())
     return std::forward<F>(code)();
 
   // If we are in the application, pass the code to the maestro which
   // 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;
+  using R = typename std::result_of_t<F()>;
   simgrid::xbt::Result<R> result;
-  simcall_run_kernel([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward<F>(code)); });
+  simcall_run_answered([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward<F>(code)); }, observer);
   return result.get();
 }
 
-XBT_ATTRIB_DEPRECATED_v325("Please manifest if you actually need this function.")
-    XBT_PUBLIC const std::vector<smx_actor_t>& process_get_runnable();
-
-// What's executed as SIMIX actor code:
-typedef std::function<void()> ActorCode;
-
-// Create an ActorCode based on a std::string
-typedef std::function<ActorCode(std::vector<std::string> args)> ActorCodeFactory;
-
-XBT_PUBLIC void register_function(std::string name, ActorCodeFactory factory);
-}
-}
-
-XBT_PUBLIC smx_actor_t simcall_process_create(std::string name, simgrid::simix::ActorCode code, void* data,
-                                              sg_host_t host, std::unordered_map<std::string, std::string>* properties);
-
-XBT_PUBLIC smx_timer_t SIMIX_timer_set(double date, simgrid::xbt::Task<void()> callback);
-
-template<class F> inline
-smx_timer_t SIMIX_timer_set(double date, F callback)
+/** Execute some code (that does not return immediately) in kernel context
+ *
+ * This is very similar to simcall() right above, but the calling actor will not get rescheduled until
+ * actor->simcall_answer() is called explicitly.
+ *
+ * This is meant for blocking actions. For example, locking a mutex is a blocking simcall.
+ * First it's a simcall because that's obviously a modification of the world. Then, that's a blocking simcall because if
+ * the mutex happens not to be free, the actor is added to a queue of actors in the mutex. Every mutex->unlock() takes
+ * the first actor from the queue, mark it as current owner of the mutex and call actor->simcall_answer() to mark that
+ * this mutex is now unblocked and ready to run again. If the mutex is initially free, the calling actor is unblocked
+ * right away with actor->simcall_answer() once the mutex is marked as locked.
+ *
+ * If your code never calls actor->simcall_answer() itself, the actor will never return from its simcall.
+ *
+ * The return value is obtained from observer->get_result() if it exists. Otherwise void is returned.
+ */
+template <class F> void simcall_blocking(F&& code, SimcallObserver* observer = nullptr)
 {
-  return SIMIX_timer_set(date, simgrid::xbt::Task<void()>(std::move(callback)));
+  xbt_assert(not s4u::Actor::is_maestro(), "Cannot execute blocking call in kernel mode");
+
+  // Pass the code to the maestro which executes it for us and reports the result. We use a std::future which
+  // conveniently handles the success/failure value for us.
+  simgrid::xbt::Result<void> result;
+  simcall_run_blocking([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward<F>(code)); }, observer);
+  result.get(); // rethrow stored exception if any
 }
 
-template<class R, class T> inline
-smx_timer_t SIMIX_timer_set(double date, R(*callback)(T*), T* arg)
+template <class F, class Observer>
+auto simcall_blocking(F&& code, Observer* observer) -> decltype(observer->get_result())
 {
-  return SIMIX_timer_set(date, [callback, arg]() { callback(arg); });
+  simcall_blocking(std::forward<F>(code), static_cast<SimcallObserver*>(observer));
+  return observer->get_result();
 }
+} // namespace actor
+} // namespace kernel
+} // namespace simgrid
 
 #endif