add ability to uniquify diag output

examples/margo-example-client.c

@@ -176,7 +176,7 @@ int main(int argc, char **argv)
     HG_Addr_free(hg_class, svr_addr);
 
     /* shut down everything */
-    margo_diag_dump(mid, "-");
+    margo_diag_dump(mid, "-", 0);
     margo_finalize(mid);
     
     ABT_finalize();

examples/my-rpc.c

@@ -102,7 +102,7 @@ static void my_rpc_shutdown_ult(hg_handle_t handle)
 
     HG_Destroy(handle);
 
-    margo_diag_dump(mid, "-");
+    margo_diag_dump(mid, "-", 0);
 
     /* NOTE: we assume that the server daemon is using
      * margo_wait_for_finalize() to suspend until this RPC executes, so there

include/margo.h

@@ -223,9 +223,11 @@ void margo_diag_start(margo_instance_id mid);
  *
  * @param [in] mid Margo instance
  * @param [in] file output file ("-" for stdout)
+ * @param [in] uniquify flag indicating if file name should have additional
+ *   information added to it to make output from different processes unique
  * @returns void
  */
-void margo_diag_dump(margo_instance_id mid, const char* file);
+void margo_diag_dump(margo_instance_id mid, const char* file, int uniquify);
 
 #define MARGO_REGISTER(__mid, __func_name, __in_t, __out_t, __handler, __mplex_id, __pool) do { \
     hg_return_t __hret; \

src/margo.c

@@ -935,20 +935,36 @@ static void print_diag_data(FILE *file, const char* name, const char *descriptio
     return;
 }
 
-void margo_diag_dump(margo_instance_id mid, const char* file)
+void margo_diag_dump(margo_instance_id mid, const char* file, int uniquify)
 {
     FILE *outfile;
     time_t ltime;
+    char revised_file_name[256] = {0};
 
     assert(mid->diag_enabled);
 
+    if(uniquify)
+    {
+        char hostname[128] = {0};
+        int pid;
+
+        gethostname(hostname, 128);
+        pid = getpid();
+
+        sprintf(revised_file_name, "%s-%s-%d", file, hostname, pid);
+    }
+    else
+    {
+        sprintf(revised_file_name, "%s", file);
+    }
+
     if(strcmp("-", file) == 0)
     {
         outfile = stdout;
     }
     else
     {
-        outfile = fopen(file, "a");
+        outfile = fopen(revised_file_name, "a");
         if(!outfile)
         {
             perror("fopen");