X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2f8d17b7da365107340aab6f75763d0a9f2cecbb..bdeb73fa38787af6728f7d01c0f6c0ae73d38b42:/src/simix/ActorImpl.hpp

diff --git a/src/simix/ActorImpl.hpp b/src/simix/ActorImpl.hpp
index 9e4930deac..9b499496d4 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 */
@@ -40,8 +42,8 @@ public:
   s_xbt_swag_hookup_t host_proc_hookup = { nullptr, nullptr }; /* smx_host->process_lis */
   s_xbt_swag_hookup_t destroy_hookup   = { nullptr, nullptr }; /* simix_global->process_to_destroy */
 
-  unsigned long pid  = 0;
-  unsigned long ppid = -1;
+  aid_t pid  = 0;
+  aid_t ppid = -1;
   simgrid::xbt::string name;
   const char* cname() { return name.c_str(); }
   s4u::Host* host       = nullptr; /* the host on which the process is running */
@@ -56,7 +58,7 @@ public:
 
   sg_host_t new_host            = nullptr; /* if not null, the host on which the process must migrate to */
   smx_activity_t waiting_synchro = nullptr; /* the current blocking synchro if any */
-  std::list<smx_activity_t> comms               ;           /* the current non-blocking communication synchros */
+  std::list<smx_activity_t> comms;          /* the current non-blocking communication synchros */
   xbt_dict_t properties         = nullptr;
   s_smx_simcall_t simcall;
   void *data          = nullptr; /* kept for compatibility, it should be replaced with moddata */
@@ -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();
 };
 
 }