From 4514daac23fcfbe8c6d340e9f4eb0e7d79704114 Mon Sep 17 00:00:00 2001
From: alegrand <alegrand@48e7efb5-ca39-0410-a469-dd3cf9ba447f>
Date: Wed, 18 Jan 2006 16:04:49 +0000
Subject: [PATCH] fix The Loc's bug. It happened only in very particular
 situations. If sender sends a task and there is no receiver, it gets blocked.
 If somebody suspends it in between, then neither the receiver nor the resumer
 was actually resuming it. Fixing it was tricky so I hope my few lines will
 make it. As time goes, MSG is getting more and more like an awfull pile of
 hack. I fear it is the next one on  the CODE_TO_REWRITE list...

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@1900 48e7efb5-ca39-0410-a469-dd3cf9ba447f
---
 src/msg/gos.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/msg/gos.c b/src/msg/gos.c
index dc3068347d..f61ed61604 100644
--- a/src/msg/gos.c
+++ b/src/msg/gos.c
@@ -92,6 +92,26 @@ static MSG_error_t __MSG_task_get_with_time_out_from_host(m_task_t * task,
   /* Transfer */
   t_simdata->using++;
 
+  while(MSG_process_is_suspended(t_simdata->sender)) {
+    DEBUG1("Oooups, the sender (%s) has been suspended in the meantime. Let's wait for him", 
+	   t_simdata->sender->name);
+    m_task_t task_to_wait_for = t_simdata->sender->simdata->waiting_task;
+    if(__MSG_process_isBlocked(t_simdata->sender)) {
+      DEBUG0("He's blocked. Let's wait for him to go in the suspended state");
+      __MSG_process_unblock(t_simdata->sender);
+      task_to_wait_for->simdata->using++;
+      __MSG_task_wait_event(process, task_to_wait_for);
+      MSG_task_destroy(task_to_wait_for);
+    } else {
+      DEBUG0("He's suspended. Let's wait for him to go in the resumed state");
+      task_to_wait_for->simdata->using++;
+      __MSG_task_wait_event(process, task_to_wait_for);
+      MSG_task_destroy(task_to_wait_for);
+      DEBUG0("He's resumed. He should block again. So let's free him.");
+      __MSG_process_unblock(t_simdata->sender);
+      break;
+    }
+  }
   DEBUG0("Calling SURF for communication creation");
   t_simdata->comm = surf_workstation_resource->extension_public->
     communicate(MSG_process_get_host(t_simdata->sender)->simdata->host,
@@ -99,8 +119,10 @@ static MSG_error_t __MSG_task_get_with_time_out_from_host(m_task_t * task,
   
   surf_workstation_resource->common_public->action_set_data(t_simdata->comm,t);
 
-  if(__MSG_process_isBlocked(t_simdata->sender))
+  if(__MSG_process_isBlocked(t_simdata->sender)) {
+    DEBUG1("Unblocking %s",t_simdata->sender->name);
     __MSG_process_unblock(t_simdata->sender);
+  }
 
   PAJE_PROCESS_PUSH_STATE(process,"C");  
 
@@ -525,6 +547,7 @@ MSG_error_t __MSG_wait_for_computation(m_process_t process, m_task_t task)
   e_surf_action_state_t state = SURF_ACTION_NOT_IN_THE_SYSTEM;
   simdata_task_t simdata = task->simdata;
 
+  XBT_IN4("(%p(%s) %p(%s))",process,process->name,task,task->name);
   simdata->using++;
   do {
     __MSG_task_wait_event(process, task);
@@ -537,16 +560,19 @@ MSG_error_t __MSG_wait_for_computation(m_process_t process, m_task_t task)
     if(surf_workstation_resource->common_public->action_free(simdata->compute)) 
       simdata->compute = NULL;
     simdata->computation_amount = 0.0;
+    XBT_OUT;
     MSG_RETURN(MSG_OK);
   } else if(surf_workstation_resource->extension_public->
 	    get_state(MSG_process_get_host(process)->simdata->host) 
 	    == SURF_CPU_OFF) {
     if(surf_workstation_resource->common_public->action_free(simdata->compute)) 
       simdata->compute = NULL;
+    XBT_OUT;
     MSG_RETURN(MSG_HOST_FAILURE);
   } else {
     if(surf_workstation_resource->common_public->action_free(simdata->compute)) 
       simdata->compute = NULL;
+    XBT_OUT;
     MSG_RETURN(MSG_TASK_CANCELLED);
   }
 }
-- 
2.20.1