X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=buffer_tree.c;h=962359fbfa253790880f1380551335eaf9861c6d;hp=7180149ee49ade68b6310bb2f596562cb8ff08a8;hb=11ef83c4abb2ccbdf3f99a8adf98749b2b0656c2;hpb=b8caed98bbe13587dfb3f59d5c53746a6c6f70a8

diff --git a/buffer_tree.c b/buffer_tree.c
index 7180149e..962359fb 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -8,6 +8,7 @@
 #include "error.h"
 #include "sched.h"
 
+/* whead = NULL means area full */
 struct btr_pool {
 	char *name;
 	char *area_start;
@@ -56,6 +57,17 @@ struct btr_node {
 	void *context;
 };
 
+/**
+ * Create a new buffer pool.
+ *
+ * \param name The name of the new buffer pool.
+ *
+ * \param area The size in bytes of the pool area.
+ *
+ * \return An opaque pointer to the newly created buffer pool. It must be
+ * passed to btr_pool_free() after it is no longer used to deallocate all
+ * resources.
+ */
 struct btr_pool *btr_pool_new(const char *name, size_t area_size)
 {
 	struct btr_pool *btrp;
@@ -70,8 +82,11 @@ struct btr_pool *btr_pool_new(const char *name, size_t area_size)
 	return btrp;
 }
 
-/* whead = NULL means area full */
-
+/**
+ * Dellocate resources used by a buffer pool.
+ *
+ * \param btrp A pointer obtained via btr_pool_new().
+ */
 void btr_pool_free(struct btr_pool *btrp)
 {
 	if (!btrp)
@@ -81,6 +96,14 @@ void btr_pool_free(struct btr_pool *btrp)
 	free(btrp);
 }
 
+/**
+ * Return the size of the buffer pool area.
+ *
+ * \param btrp The buffer pool.
+ *
+ * \return The same value which was passed during creation time to
+ * btr_pool_new().
+ */
 size_t btr_pool_size(struct btr_pool *btrp)
 {
 	return btrp->area_end - btrp->area_start;
@@ -168,14 +191,6 @@ static void btr_pool_deallocate(struct btr_pool *btrp, size_t size)
 #define FOR_EACH_BUFFER_REF_SAFE(_br, _tmp, _btrn) \
 	list_for_each_entry_safe((_br), (_tmp), &(_btrn)->input_queue, node)
 
-/*
-	(parent, child):
-	(NULL, NULL): new, isolated node.
-	(NULL, c): new node becomes root, c must be old root
-	(p, NULL): new leaf node
-	(p, c): new internal node, ch must be child of p
-
-*/
 struct btr_node *btr_new_node(struct btr_node_description *bnd)
 {
 	struct btr_node *btrn = para_malloc(sizeof(*btrn));
@@ -186,14 +201,31 @@ struct btr_node *btr_new_node(struct btr_node_description *bnd)
 	btrn->context = bnd->context;
 	btrn->start.tv_sec = 0;
 	btrn->start.tv_usec = 0;
-	if (bnd->parent)
-		list_add_tail(&btrn->node, &bnd->parent->children);
 	INIT_LIST_HEAD(&btrn->children);
 	INIT_LIST_HEAD(&btrn->input_queue);
-	if (bnd->parent)
-		PARA_INFO_LOG("added %s as child of %s\n", bnd->name, bnd->parent->name);
-	else
-		PARA_INFO_LOG("added %s as btr root\n", bnd->name);
+	if (!bnd->child) {
+		if (bnd->parent) {
+			list_add_tail(&btrn->node, &bnd->parent->children);
+			PARA_INFO_LOG("new leaf node: %s (child of %s)\n",
+				bnd->name, bnd->parent->name);
+		} else
+			PARA_INFO_LOG("added %s as btr root\n", bnd->name);
+		goto out;
+	}
+	if (!bnd->parent) {
+		assert(!bnd->child->parent);
+		PARA_INFO_LOG("new root: %s (was %s)\n",
+			bnd->name, bnd->child->name);
+		btrn->parent = NULL;
+		list_add_tail(&bnd->child->node, &btrn->children);
+		/* link it in */
+		bnd->child->parent = btrn;
+		goto out;
+	}
+	PARA_EMERG_LOG("inserting internal nodes not yet supported.\n");
+	exit(EXIT_FAILURE);
+	assert(bnd->child->parent == bnd->parent);
+out:
 	return btrn;
 }