first cut at refactor of darshan-core for no mpi

darshan-runtime/darshan-common.h

@@ -263,6 +263,7 @@ void darshan_common_val_counter(
     int64_t *val_p,
     int64_t *cnt_p);
 
+#ifdef HAVE_MPI
 /* darshan_variance_reduce()
  *
  * MPI reduction operation to calculate variances on counters in
@@ -279,5 +280,6 @@ void darshan_variance_reduce(
     void *inoutvec,
     int *len,
     MPI_Datatype *dt);
+#endif
 
 #endif /* __DARSHAN_COMMON_H */

darshan-runtime/darshan-core.h

@@ -7,12 +7,19 @@
 #ifndef __DARSHAN_CORE_H
 #define __DARSHAN_CORE_H
 
+#include "darshan-runtime-config.h"
+
 #include <unistd.h>
 #include <sys/types.h>
 #include <stdint.h>
 #include <limits.h>
 
+#ifdef HAVE_MPI
+#include <mpi.h>
+#endif
+
 #include "uthash.h"
+#include "darshan.h"
 #include "darshan-log-format.h"
 
 /* Environment variable to override __DARSHAN_JOBID */
@@ -48,13 +55,32 @@
 /* default name record buf can store 2048 records of size 100 bytes */
 #define DARSHAN_NAME_RECORD_BUF_SIZE (2048 * 100)
 
+typedef union
+{
+    int nompi_fd;
+#ifdef HAVE_MPI
+    MPI_File mpi_fh;
+#endif
+} darshan_core_log_fh;
+
+/* FS mount information */
+#define DARSHAN_MAX_MNTS 64
+#define DARSHAN_MAX_MNT_PATH 256
+#define DARSHAN_MAX_MNT_TYPE 32
+struct darshan_core_mnt_data
+{
+    char path[DARSHAN_MAX_MNT_PATH];
+    char type[DARSHAN_MAX_MNT_TYPE];
+    struct darshan_fs_info fs_info;
+};
+
 /* structure to track registered modules */
 struct darshan_core_module
 {
     void *rec_buf_start;
     void *rec_buf_p;
     int rec_mem_avail;
-    darshan_module_shutdown mod_shutdown_func;
+    darshan_module_funcs mod_funcs;
 };
 
 /* strucutre for keeping a reference to registered name records */

darshan-runtime/darshan.h

@@ -10,7 +10,10 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <stdint.h>
+
+#ifdef HAVE_MPI
 #include <mpi.h>
+#endif
 
 #include "darshan-log-format.h"
 #include "darshan-common.h"
@@ -76,22 +79,36 @@
 /* default number of records to attempt to store for each module */
 #define DARSHAN_DEF_MOD_REC_COUNT 1024
 
-/* module developers must define a 'darshan_module_shutdown' function
+#ifdef HAVE_MPI
+/*
+ * module developers _can_ define a 'darshan_module_redux' 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. Set to NULL
+ * avoid any reduction steps.
+ */
+typedef void (*darshan_module_redux)(
+    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 */
+);
+#endif
+/*
+ * 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 */
 );
+typedef struct darshan_module_funcs
+{
+#ifdef HAVE_MPI
+    darshan_module_redux mod_redux_func;
+#endif
+    darshan_module_shutdown mod_shutdown_func;
+} darshan_module_funcs;
 
 /* stores FS info from statfs calls for a given mount point */
 struct darshan_fs_info
@@ -124,10 +141,10 @@ void darshan_instrument_fs_data(
  *
  * Register module identifier 'mod_id' with the darshan-core runtime
  * environment, allowing the module to store I/O characterization data.
- * 'mod_shutdown_func is a pointer to a function responsible for
- * shutting down the module and returning final output data to darshan-core.
- * 'inout_mod_buf_size' is an input/output argument, with it being
- * set to the requested amount of module memory on input, and set to
+ * 'mod_funcs' is a set of function pointers that implement module-specific
+ * shutdown functionality (including a possible data reduction step when
+ * using MPI). 'inout_mod_buf_size' is an input/output argument, with it
+ * being set to the requested amount of module memory on input, and set to
  * the amount allocated by darshan-core on output. If given, 'rank' is
  * a pointer to an integer which will contain the calling process's
  * MPI rank on return. If given, 'sys_mem_alignment' is a pointer to
@@ -136,7 +153,7 @@ void darshan_instrument_fs_data(
  */
 void darshan_core_register_module(
     darshan_module_id mod_id,
-    darshan_module_shutdown mod_shutdown_func,
+    darshan_module_funcs mod_funcs,
     int *inout_mod_buf_size,
     int *rank,
     int *sys_mem_alignment);