MSG_process_get_data(): don't segfault if there the process has been cleaned up

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

diff --git a/src/msg/msg_process.c b/src/msg/msg_process.c
index 3a38913..44d3838 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 ************************************/
@@ -153,7 +151,7 @@ msg_process_t MSG_process_create_with_environment(const char *name,
                                                 int argc, char **argv,
                                                 xbt_dict_t properties)
 {
-  xbt_assert(code != NULL && host != NULL, "Invalid parameters");
+  xbt_assert(code != NULL && host != NULL, "Invalid parameters: host and code params must not be NULL");
   simdata_process_t simdata = xbt_new0(s_simdata_process_t, 1);
   msg_process_t process;
 
@@ -237,11 +235,14 @@ msg_error_t MSG_process_migrate(msg_process_t process, msg_host_t host)
  */
 void* MSG_process_get_data(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: first parameter must not be NULL!");
 
   /* 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
@@ -252,7 +253,7 @@ void* MSG_process_get_data(msg_process_t process)
  */
 msg_error_t MSG_process_set_data(msg_process_t process, void *data)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: first parameter must not be NULL!");
 
   simdata_process_t simdata = simcall_process_get_data(process);
   simdata->data = data;
@@ -350,7 +351,7 @@ int MSG_process_get_PID(msg_process_t process)
  */
 int MSG_process_get_PPID(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
 
   return simcall_process_get_PPID(process);
 }
@@ -363,7 +364,7 @@ int MSG_process_get_PPID(msg_process_t process)
  */
 const char *MSG_process_get_name(msg_process_t process)
 {
-  xbt_assert(process, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
 
   return simcall_process_get_name(process);
 }
@@ -388,7 +389,7 @@ const char *MSG_process_get_property_value(msg_process_t process,
  */
 xbt_dict_t MSG_process_get_properties(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
 
   return simcall_process_get_properties(process);
 
@@ -433,7 +434,7 @@ msg_process_t MSG_process_self(void)
  */
 msg_error_t MSG_process_suspend(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
 
   TRACE_msg_process_suspend(process);
   simcall_process_suspend(process);
@@ -448,7 +449,7 @@ msg_error_t MSG_process_suspend(msg_process_t process)
  */
 msg_error_t MSG_process_resume(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
 
   TRACE_msg_process_resume(process);
   simcall_process_resume(process);
@@ -463,7 +464,7 @@ msg_error_t MSG_process_resume(msg_process_t process)
  */
 int MSG_process_is_suspended(msg_process_t process)
 {
-  xbt_assert(process != NULL, "Invalid parameter");
+  xbt_assert(process != NULL, "Invalid parameter: First argument must not be NULL");
   return simcall_process_is_suspended(process);
 }