X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/82af9c443eb39b534153396598f68562ed6eac98..041733d27687138580274a397bb287da01c48b4c:/src/simix/ActorImpl.hpp

diff --git a/src/simix/ActorImpl.hpp b/src/simix/ActorImpl.hpp
index 906c4cd274..b15d40ef10 100644
--- a/src/simix/ActorImpl.hpp
+++ b/src/simix/ActorImpl.hpp
@@ -9,12 +9,13 @@
 #include "simgrid/s4u/Actor.hpp"
 #include "src/simix/popping_private.h"
 #include "xbt/swag.h"
-#include<list>
+#include <list>
 
 typedef struct s_smx_process_exit_fun {
   int_f_pvoid_pvoid_t fun;
   void *arg;
-} s_smx_process_exit_fun_t, *smx_process_exit_fun_t;
+} s_smx_process_exit_fun_t;
+typedef s_smx_process_exit_fun_t* smx_process_exit_fun_t;
 
 namespace simgrid {
 namespace simix {
@@ -33,6 +34,7 @@ public:
 class ActorImpl {
 public:
   ActorImpl() : piface_(this) {}
+  ~ActorImpl();
 
   // TODO, replace with boost intrusive container hooks
   s_xbt_swag_hookup_t process_hookup   = { nullptr, nullptr }; /* simix_global->process_list */
@@ -66,31 +68,43 @@ public:
   smx_timer_t kill_timer = nullptr;
   int segment_index = -1; /* Reference to an SMPI process' data segment. Default value is -1 if not in SMPI context*/
 
+  /* Refcounting */
+private:
+  std::atomic_int_fast32_t refcount_{0};
+
+public:
   friend void intrusive_ptr_add_ref(ActorImpl* process)
   {
-    process->refcount_.fetch_add(1, std::memory_order_relaxed);
+    // std::memory_order_relaxed ought to be enough here instead of std::memory_order_seq_cst
+    // But then, we have a threading issue when an actor commits a suicide:
+    //  it seems that in this case, the worker thread kills the last occurrence of the actor
+    //  while usually, the maestro does so. FIXME: we should change how actors suicide
+    process->refcount_.fetch_add(1, std::memory_order_seq_cst);
   }
   friend void intrusive_ptr_release(ActorImpl* process)
   {
     // inspired from http://www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html
     if (process->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
+      // Make sure that any changes done on other threads before their acquire are committed before our delete
+      // http://stackoverflow.com/questions/27751025/why-is-an-acquire-barrier-needed-before-deleting-the-data-in-an-atomically-refer
       std::atomic_thread_fence(std::memory_order_acquire);
       delete process;
     }
   }
 
-  ~ActorImpl();
-
+  /* S4U/implem interfaces */
+private:
+  simgrid::s4u::Actor piface_; // Our interface is part of ourselves
+public:
   simgrid::s4u::ActorPtr iface() { return s4u::ActorPtr(&piface_); }
   simgrid::s4u::Actor* ciface() { return &piface_; }
 
-  void daemonize();
-  bool isDaemon();
-
+  /* Daemon actors are automatically killed when the last non-daemon leaves */
 private:
   bool daemon = false;
-  std::atomic_int_fast32_t refcount_ { 1 };
-  simgrid::s4u::Actor piface_; // Our interface is part of ourselves
+public:
+  void daemonize();
+  bool isDaemon();
 };
 
 }
@@ -118,17 +132,13 @@ XBT_PRIVATE void SIMIX_process_empty_trash();
 XBT_PRIVATE void SIMIX_process_yield(smx_actor_t self);
 XBT_PRIVATE void SIMIX_process_exception_terminate(xbt_ex_t * e);
 XBT_PRIVATE void SIMIX_process_change_host(smx_actor_t process, sg_host_t dest);
-XBT_PRIVATE smx_activity_t SIMIX_process_suspend(smx_actor_t process, smx_actor_t issuer);
 XBT_PRIVATE void SIMIX_process_resume(smx_actor_t process);
 XBT_PRIVATE int SIMIX_process_get_PID(smx_actor_t self);
 XBT_PRIVATE void SIMIX_process_set_data(smx_actor_t process, void *data);
 XBT_PRIVATE smx_actor_t SIMIX_process_get_by_name(const char* name);
 XBT_PRIVATE int SIMIX_process_is_suspended(smx_actor_t process);
 XBT_PRIVATE xbt_dict_t SIMIX_process_get_properties(smx_actor_t process);
-XBT_PRIVATE smx_activity_t SIMIX_process_join(smx_actor_t issuer, smx_actor_t process, double timeout);
-XBT_PRIVATE smx_activity_t SIMIX_process_sleep(smx_actor_t process, double duration);
 
-XBT_PRIVATE void SIMIX_process_sleep_destroy(smx_activity_t synchro);
 XBT_PRIVATE void SIMIX_process_auto_restart_set(smx_actor_t process, int auto_restart);
 XBT_PRIVATE smx_actor_t SIMIX_process_restart(smx_actor_t process, smx_actor_t issuer);
 
@@ -137,4 +147,9 @@ extern void (*SMPI_switch_data_segment)(int dest);
 
 SG_END_DECL()
 
+XBT_PRIVATE void SIMIX_process_sleep_destroy(smx_activity_t synchro);
+XBT_PRIVATE smx_activity_t SIMIX_process_suspend(smx_actor_t process, smx_actor_t issuer);
+XBT_PRIVATE smx_activity_t SIMIX_process_join(smx_actor_t issuer, smx_actor_t process, double timeout);
+XBT_PRIVATE smx_activity_t SIMIX_process_sleep(smx_actor_t process, double duration);
+
 #endif