convert to a single module shutdown function

rather than using 'begin_shutdown', 'get_output_data', and
'shutdown', we combine all three into one shutdown routine.

darshan-runtime/darshan-core.h

@@ -55,7 +55,7 @@ struct darshan_core_module
     void *rec_buf_start;
     void *rec_buf_p;
     int rec_mem_avail;
-    struct darshan_module_funcs funcs;
+    darshan_module_shutdown mod_shutdown_func;
 };
 
 /* strucutre for keeping a reference to registered name records */

darshan-runtime/darshan.h

@@ -56,32 +56,22 @@
 /* default number of records to attempt to store for each module */
 #define DARSHAN_DEF_MOD_REC_COUNT 1024
 
-/* module developers provide the following functions to darshan-core */
-struct darshan_module_funcs
-{
-    /* perform any necessary pre-shutdown steps
-     *
-     * NOTE: this typically includes disabling wrapper functions so
-     * darshan-core can shutdown in a consistent state.
-     */
-    void (*begin_shutdown)(void);
-    /* retrieve module data to write to log file
-     *
-     * NOTE: module developers can use this function to run collective
-     * MPI operations at shutdown time. Typically this functionality
-     * has been used to reduce records shared globablly (given in the
-     * 'shared_recs' array) into a single data record.
-     */
-    void (*get_output_data)(
-        MPI_Comm mod_comm,  /* MPI communicator to run collectives with */
-        darshan_record_id *shared_recs, /* list of shared data record ids */
-        int shared_rec_count, /* count of shared data records */
-        void** mod_buf, /* output parameter to save module buffer address */
-        int* mod_buf_sz /* output parameter to save module buffer size */
-    );
-    /* shutdown module data structures */
-    void (*shutdown)(void);
-};
+/* module developers must define a 'darshan_module_shutdown' function
+ * for allowing darshan-core to call into a module and retrieve final
+ * output data to be saved in the log.
+ *
+ * NOTE: module developers can use this function to run collective
+ * MPI operations at shutdown time. Typically this functionality
+ * has been used to reduce records shared globablly (given in the
+ * 'shared_recs' array) into a single data record.
+ */
+typedef void (*darshan_module_shutdown)(
+    MPI_Comm mod_comm,  /* MPI communicator to run collectives with */
+    darshan_record_id *shared_recs, /* list of shared data record ids */
+    int shared_rec_count, /* count of shared data records */
+    void **mod_buf, /* output parameter to save module buffer address */
+    int *mod_buf_sz /* output parameter to save module buffer size */
+);
 
 /*****************************************************
 * darshan-core functions exported to darshan modules *
@@ -103,7 +93,7 @@ struct darshan_module_funcs
  */
 void darshan_core_register_module(
     darshan_module_id mod_id,
-    struct darshan_module_funcs *funcs,
+    darshan_module_shutdown mod_shutdown_func,
     int *inout_mod_buf_size,
     int *rank,
     int *sys_mem_alignment);

darshan-runtime/lib/darshan-core.c

@@ -406,10 +406,7 @@ void darshan_core_shutdown()
     for(i = 0; i < DARSHAN_MAX_MODS; i++)
     {
         if(final_core->mod_array[i])
-        {
             local_mod_use[i] = 1;
-            final_core->mod_array[i]->funcs.begin_shutdown();
-        }
     }
 
     /* reduce the number of times a module was opened globally and bcast to everyone */
@@ -566,7 +563,7 @@ void darshan_core_shutdown()
         {
             mod_buf = final_core->mod_array[i]->rec_buf_start;
             mod_buf_sz = final_core->mod_array[i]->rec_buf_p - mod_buf;
-            this_mod->funcs.get_output_data(MPI_COMM_WORLD, mod_shared_recs,
+            this_mod->mod_shutdown_func(MPI_COMM_WORLD, mod_shared_recs,
                 mod_shared_rec_cnt, &mod_buf, &mod_buf_sz);
         }
 
@@ -593,11 +590,6 @@ void darshan_core_shutdown()
             return;
         }
 
-        /* shutdown module if registered locally */
-        if(this_mod)
-        {
-            this_mod->funcs.shutdown();
-        }
         if(internal_timing_flag)
             mod2[i] = DARSHAN_MPI_CALL(PMPI_Wtime)();
     }
@@ -1692,7 +1684,7 @@ static void darshan_core_cleanup(struct darshan_core_runtime* core)
 
 void darshan_core_register_module(
     darshan_module_id mod_id,
-    struct darshan_module_funcs *funcs,
+    darshan_module_shutdown mod_shutdown_func,
     int *inout_mod_buf_size,
     int *rank,
     int *sys_mem_alignment)
@@ -1730,7 +1722,7 @@ void darshan_core_register_module(
         mod->rec_mem_avail = mod_mem_avail;
     mod->rec_buf_start = darshan_core->log_mod_p + darshan_core->mod_mem_used;
     mod->rec_buf_p = mod->rec_buf_start;
-    mod->funcs = *funcs;
+    mod->mod_shutdown_func = mod_shutdown_func;
 
     /* register module with darshan */
     darshan_core->mod_array[mod_id] = mod;