[padb] r313 committed - Update the minfo code to use the proposed new interface for discoverin...

[padb at googlecode.com]

Revision: 313
Author: apittman
Date: Tue Nov  3 04:15:34 2009
Log: Update the minfo code to use the proposed new interface for discovering
dlls.  Everything should still work as before except an extra variable
is checked in the target process.
Also add some more error checking and report a couple of errors to the user
should they occour.

http://code.google.com/p/padb/source/detail?r=313

Modified:
  /trunk/src/minfo.c

=======================================
--- /trunk/src/minfo.c	Thu Oct 29 15:52:20 2009
+++ /trunk/src/minfo.c	Tue Nov  3 04:15:34 2009
@@ -11,6 +11,7 @@

  #include <dlfcn.h>
  #include <unistd.h>
+#include <assert.h>
  #include "mpi_interface.h"

  struct dll_entry_points {
@@ -108,8 +109,9 @@

  #define QUERY_SIZE 1280

-/* Query (via proxy) gdb for the answer to a question,
- * store the restult in ans, returns -1 on failure */
+/* Query (via proxy) gdb for the answer to a question, store the result in
+ * ans, returns -1 on failure
+ */
  int ask(char *req, char *ans)
  {
      char buff[QUERY_SIZE+3];
@@ -117,8 +119,10 @@
      printf("req: %s\n",req);
      fflush(NULL);
      nbytes = read(0,buff,QUERY_SIZE+3);
-    if ( nbytes < 0 )
+    if ( nbytes < 0 ) {
+	show_warning("Bad result from read");
  	return -1;
+    }
      if ( memcmp(buff,"ok ",3 ) )
  	return -1;
      buff[nbytes-1] = '\000';
@@ -317,8 +321,9 @@
      return mqs_ok;
  }

-// Data comes back as 0x?? for each char, space required is (N*5)-1
-// 256 bytes read need 1279 bytes of space
+/* Data comes back as 0x?? for each char, space required is (N*5)-1 256
+ * bytes read need 1279 bytes of space
+ */
  int find_data (mqs_process *proc, mqs_taddr_t addr, int size, void *base)
  {
      char *local = base;
@@ -347,17 +352,22 @@
      memcpy(b,(void *)a,size);
  }

+/* Fetch a string from a remote memory location, making sure there is
+ * enough memory locally to store our copy.  Return mqs_ok on success */
  int fetch_string (void *bc,void *local, mqs_taddr_t remote, int size)
  {
      char req[128];
-    char ans[128];
+    char *ans = malloc(size+16);
      int i;

      sprintf(req,"string %d %p",size,(void *)remote);
      i = ask(req,ans);
-    if ( i != 0 )
+    if ( i != 0 ) {
+	free(ans);
  	return -1;
+    }
      strncpy(local,ans,size);
+    free(ans);
      return 0;
  }

@@ -533,20 +543,98 @@
      DLSYM(dll_ep,dlhandle,next_communicator);
      DLSYM(dll_ep,dlhandle,setup_operation_iterator);
      DLSYM(dll_ep,dlhandle,next_operation);
-    DLSYM(dll_ep,dlhandle,get_comm_group);
-
+
+    /* "Optional" symbols, these may or may not occour in the dll, if they
+     *  are we can make use of them but if they aren't then that's fine too
+     */
+    DLSYM_LAX(dll_ep,dlhandle,get_comm_group);
      DLSYM_LAX(dll_ep,dlhandle,get_global_rank);
      DLSYM_LAX(dll_ep,dlhandle,get_comm_coll_state);
      return 0;
  }

  #define PATH_MAX 1024
+
+/* Try and load a valid dll from the locations array, loop over the array
+ * trying each one in turn.  Return 0 if and when we managed to load one,
+ * -1 otherwise
+ */
+int find_and_load_dll_from_loc_array() {
+    void **remote_array;
+    char *dll_name;
+    void *locations = find_sym("sym","mpimsgq_dll_locations");
+
+    if ( locations == NULL )
+	return -1;
+
+    if ( find_data(NULL,(mqs_taddr_t)locations,sizeof(void  
*),&remote_array) != mqs_ok ) {
+	return -1;
+    }
+
+    if ( (dll_name = malloc(PATH_MAX)) == NULL )
+	return -1;
+
+    do {
+	void *remote_entry = NULL;
+
+    	if ( find_data(NULL,(mqs_taddr_t)remote_array,sizeof(void  
*),&remote_entry) != mqs_ok )
+	    goto error_out;
+
+	if ( remote_entry == NULL )
+	    goto error_out;
+
+	memset(dll_name,0,PATH_MAX);
+
+	if ( fetch_string(NULL,dll_name,(mqs_taddr_t)remote_entry,PATH_MAX) !=  
mqs_ok ) {
+	    goto error_out;
+
+	} else {
+	    if ( load_msgq_dll(dll_name) == 0 ) {
+		free(dll_name);
+		return mqs_ok;
+	    }
+	}
+	remote_array++;
+    } while ( 1 );
+
+error_out:
+    free(dll_name);
+    return -1;
+}
+
+void find_and_load_dll()
+{
+    char *dll_name;
+
+    dll_name = getenv("MPINFO_DLL");
+    if ( dll_name != NULL ) {
+	if ( load_msgq_dll(dll_name) != 0 ) {
+	    die("Could not load symbols from dll");
+	}
+	return;
+    }
+
+    /* Try the new (proposed) dll specification mechanism */
+    if ( find_and_load_dll_from_loc_array() == mqs_ok )
+	return;
+
+    void *base = find_sym("sym","MPIR_dll_name");
+    if ( base == NULL ) {
+	die("Could not find MPIR_dll_name symbol");
+    }
+    dll_name = malloc(PATH_MAX);
+    if ( fetch_string(NULL,dll_name,(mqs_taddr_t)base,PATH_MAX) != 0 ) {
+	die("Could not read value of MPIR_dll_name");
+    }
+    if ( load_msgq_dll(dll_name) != 0 ) {
+	die("Could not load symbols from dll");
+    }
+}

  int
  main ()
  {
      int res;
-    char *dll_name;
      int comm_id = 0;

      struct image   image;
@@ -555,22 +643,9 @@
      mqs_image   *target_image   = (mqs_image   *)ℑ
      mqs_process *target_process = (mqs_process *)&process;

-    dll_name = getenv("MPINFO_DLL");
-    if ( ! dll_name ) {
-
-	void *base = find_sym("sym","MPIR_dll_name");
-	if ( ! base ) {
-	    die("Could not find MPIR_dll_name symbol");
-	}
-	dll_name = malloc(PATH_MAX);
-	if ( fetch_string(NULL,dll_name,(mqs_taddr_t)base,PATH_MAX) != 0 ) {
-	    die("Could not read value of MPIR_dll_name");
-	}
-    }
-
-    if ( load_msgq_dll(dll_name) != 0 ) {
-	die("Could not load symbols from dll");
-    }
+    find_and_load_dll();
+
+    assert(dll_ep.setup_basic_callbacks != NULL);

      bcb.mqs_malloc_fp           = malloc;
      bcb.mqs_free_fp             = free;