Merge pull request #17 from mpoquet/master

[simgrid.git] / src / msg / msg_process.c

diff --git a/src/msg/msg_process.c b/src/msg/msg_process.c
index d78beb5..419e710 100644 (file)
--- a/src/msg/msg_process.c
+++ b/src/msg/msg_process.c
@@ -15,11 +15,9 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(msg_process, msg,
 /** @addtogroup m_process_management
  * \htmlonly <!-- DOXYGEN_NAVBAR_LABEL="Processes" --> \endhtmlonly
  *
- *  We need to simulate many independent scheduling decisions, so
- *  the concept of <em>process</em> is at the heart of the
- *  simulator. A process may be defined as a <em>code</em>, with
- *  some <em>private data</em>, executing in a <em>location</em>.
- *  \see msg_process_t
+ *  Processes (#msg_process_t) are independent agents that can do stuff on their own. They are in charge of executing your code interacting with the simulated world.
+ *  A process may be defined as a <em>code</em> with some <em>private data</em>.
+ *  Processes must be located on <em>hosts</em> (#msg_host_t), and they exchange data by sending tasks (#msg_task_t) that are similar to envelops containing data.
  */
 
 /******************************** Process ************************************/
@@ -166,12 +164,14 @@ msg_process_t MSG_process_create_with_environment(const char *name,
   simdata->data = data;
   simdata->last_errno = MSG_OK;
 
+  int future_simix_process_pid = SIMIX_process_get_maxpid();
+  TRACE_msg_process_create(name, future_simix_process_pid, host);
+
   /* Let's create the process: SIMIX may decide to start it right now,
    * even before returning the flow control to us */
- simcall_process_create(&process, name, code, simdata, sg_host_name(host), -1,
+  simcall_process_create(&process, name, code, simdata, sg_host_name(host), -1,
                            argc, argv, properties,0);
-
-  TRACE_msg_process_create(name, SIMIX_process_get_PID(process), host);
+  xbt_assert(future_simix_process_pid == SIMIX_process_get_PID(process));
 
   if (!process) {
     /* Undo everything we have just changed */
@@ -241,7 +241,10 @@ void* MSG_process_get_data(msg_process_t process)
 
   /* get from SIMIX the MSG process data, and then the user data */
   simdata_process_t simdata = simcall_process_get_data(process);
-  return simdata->data;
+  if (simdata)
+    return simdata->data;
+  else
+    return NULL;
 }
 
 /** \ingroup m_process_management