* prof_file.c: Don't double lock the mutex (causes hang). Also, only …

…check timestamp if the file is already in the shared tree data. Otherwise just read it. * prof_set.c: Check to see whether the file is read only or has already been written to *before* mangling the shared tree data. * prof_threads.h: Use default pthread attributes when initializing mutex.

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/meeroh-profile-sharing-optimization@14468 dc483132-0cff-0310-8789-dd5450dbe970

src/util/profile/ChangeLog

@@ -1,3 +1,11 @@
+2002-06-04 Alexandra Ellwood <lxs@mit.edu>
+    * prof_file.c: Don't double lock the mutex (causes hang).  Also, only 
+    check timestamp if the file is already in the shared tree data.  Otherwise
+    just read it.  
+    * prof_set.c: Check to see whether the file is read only or has already 
+    been written to *before* mangling the shared tree data.
+    * prof_threads.h: Use default pthread attributes when initializing mutex.
+
 2002-05-16 Alexandra Ellwood <lxs@mit.edu>
 	* prof_file.c, prof_init.c, prof_int.h, prof_set.c, profile.hin:
 	Removed use of FSSpecs by the profile library other than FSSpec 

src/util/profile/prof_file.c

@@ -173,8 +173,9 @@ errcode_t profile_open_file(filespec, ret_prof)
 			data -> refcount++;
 			prf -> data = data;
 			*ret_prof = prf;
-			retval = profile_update_file_data (data); /* make sure the saved file hasn't changed */
 			prof_mutex_unlock (&g_shared_trees_mutex);
+            /* make sure the saved file hasn't changed -- mutex must be unlocked */
+			retval = profile_update_file_data (data); 
 			goto end;
 		}
 		/* We unlock the mutex here to avoid holding the mutex while we are reading in 
@@ -258,35 +259,36 @@ errcode_t profile_update_file_data(data)
 	}
 #endif /* SHARE_TREE_DATA */
 
-#ifdef HAVE_STAT
-	if (stat(data->filespec, &st)) {
-		retval = errno;
-		goto end;
-	}
-	if (st.st_mtime == data->timestamp) {
-		retval = 0;
-		goto end;
-	}
+#ifdef HAVE_STAT	
+    /* Get the mod date of the file and verify it exists 
+     * Don't worry about the cached data... profile_open_file
+     * won't let callers see it if they don't have access() 
+     */
+    if (stat(data->filespec, &st)) {
+        retval = errno;
+        goto end;
+    }
+#endif
+
 	if (data->root) {
-		profile_free_node(data->root);
-		data->root = 0;
-	}
-	if (data->comment) {
-		free(data->comment);
-		data->comment = 0;
-	}
+        /* If the profile structure is already filled in,
+         * check to make sure we need to read it
+         */
+#ifdef HAVE_STAT	
+        if (st.st_mtime == data->timestamp) {
+            retval = 0;
+            goto end;
+        }
 #else
-	/*
-	 * If we don't have the stat() call, assume that our in-core
-	 * memory image is correct.  That is, we won't reread the
-	 * profile file if it changes.
-	 */
-	if (data->root) {
+        /* If we don't have the stat() call, assume that our in-core
+         * memory image is correct.  That is, we won't reread the
+         * profile file if it changes.
+         */
 		retval = 0;
 		goto end;
-	}
-
 #endif
+    }
+
 	errno = 0;
 	f = fopen(data->filespec, "r");
 	if (f == NULL) {
@@ -299,6 +301,19 @@ errcode_t profile_update_file_data(data)
 	data->flags = 0;
 	if (read_write_access(data->filespec))
 		data->flags |= PROFILE_FILE_RW;
+
+    if (data->root) {
+        /* Free the old copy before profile_parse_file 
+         * overwrites the pointer */
+        profile_free_node(data->root);
+        data->root = 0;
+    }
+    if (data->comment) {
+        /* Free the old copy */
+        free(data->comment);
+        data->comment = 0;
+    }
+
 	retval = profile_parse_file(f, &data->root);
 	fclose(f);
 	if (retval) {
@@ -457,8 +472,8 @@ void profile_free_file_data(data)
 {
 #ifdef SHARE_TREE_DATA
 	if ((data -> flags & PROFILE_FILE_SHARED) != 0) {
+        /* caller (profile_free_file) locked us */
 		/* Remove from the global list first */
-		prof_mutex_lock (&g_shared_trees_mutex);
 		if (g_shared_trees == data) {
 			g_shared_trees = data -> next;
 		} else {
@@ -475,7 +490,6 @@ void profile_free_file_data(data)
 				next = next -> next;
 			}
 		}
-		prof_mutex_unlock (&g_shared_trees_mutex);
 	}
 #endif /* SHARE_TREE_DATA */
 

src/util/profile/prof_set.c

@@ -34,6 +34,13 @@ static errcode_t rw_setup(profile)
 
 	file = profile->first_file;
 
+	if (!(file->data->flags & PROFILE_FILE_RW))
+		return PROF_READ_ONLY;
+
+	/* Don't update the file if we've already made modifications */
+	if (file->data->flags & PROFILE_FILE_DIRTY)
+		return 0;
+
 #ifdef SHARE_TREE_DATA
 	prof_mutex_lock (&g_shared_trees_mutex);
 	/* If the file is shared and we want to write to it, get a lock */
@@ -71,13 +78,6 @@ static errcode_t rw_setup(profile)
 	}
 #endif /* SHARE_TREE_DATA */
 
-	if (!(file->data->flags & PROFILE_FILE_RW))
-		return PROF_READ_ONLY;
-
-	/* Don't update the file if we've already made modifications */
-	if (file->data->flags & PROFILE_FILE_DIRTY)
-		return 0;
-
 	retval = profile_update_file_data(file->data);
 
 	return retval;

src/util/profile/prof_threads.h

@@ -14,7 +14,7 @@
 typedef pthread_mutex_t prof_mutex;
 
 #define prof_mutex_init(mutex)											\
-	pthread_mutex_init (mutex, PTHREAD_PROCESS_PRIVATE)
+	pthread_mutex_init (mutex, /* default attributes */ NULL)
 #define prof_mutex_lock(mutex)											\
 	pthread_mutex_lock (mutex)
 #define prof_mutex_unlock(mutex)										\