From e84353bc7028ad5f6d6c17dbb3217e1ec24d0baf Mon Sep 17 00:00:00 2001
From: alegrand <alegrand@48e7efb5-ca39-0410-a469-dd3cf9ba447f>
Date: Fri, 5 Nov 2004 23:11:33 +0000
Subject: [PATCH] Extract returns the object to remove if present in the swag
 and NULL otherwise. Add a function to initialize a swag already malloced.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@490 48e7efb5-ca39-0410-a469-dd3cf9ba447f
---
 include/xbt/swag.h |  4 +++-
 src/xbt/swag.c     | 33 +++++++++++++++------------------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/include/xbt/swag.h b/include/xbt/swag.h
index 75ce3451ae..3b8a0e7c9c 100644
--- a/include/xbt/swag.h
+++ b/include/xbt/swag.h
@@ -23,8 +23,9 @@ typedef struct xbt_swag {
 } s_xbt_swag_t, *xbt_swag_t;
 
 xbt_swag_t xbt_swag_new(size_t offset);
+void xbt_swag_init(xbt_swag_t swag, size_t offset);
 void  xbt_swag_insert(void *obj,xbt_swag_t swag);
-void xbt_swag_extract(void *obj, xbt_swag_t swag);
+void *xbt_swag_extract(void *obj, xbt_swag_t swag);
 int  xbt_swag_size(xbt_swag_t swag);
 int  xbt_swag_belongs(void *obj,xbt_swag_t swag);
 
@@ -36,6 +37,7 @@ static __inline__ void *xbt_swag_getFirst(xbt_swag_t swag)
 #define xbt_swag_getNext(obj,offset) (((xbt_swag_hookup_t)(((char *) (obj)) + (offset)))->prev)
 #define xbt_swag_getPrev(obj,offset) (((xbt_swag_hookup_t)(((char *) (obj)) + (offset)))->next)
 
+#define xbt_swag_offset(var,field) ((char *)&( (var).field ) - (char *)&(var)) 
 
 #define xbt_swag_foreach(obj,swag)                            \
    for(obj=xbt_swag_getFirst(swag);                           \
diff --git a/src/xbt/swag.c b/src/xbt/swag.c
index 36df2b9cfb..8759e67b3c 100644
--- a/src/xbt/swag.c
+++ b/src/xbt/swag.c
@@ -9,9 +9,9 @@
 
 /* This type should be added to a type that is to be used in such a swag */
 
-#include <stdlib.h>
-#include <stdio.h>
-#include "swag.h"
+#include "xbt/sysdep.h"
+#include "xbt/error.h"
+#include "xbt/swag.h"
 
 #define PREV(obj,offset) xbt_swag_getPrev(obj,offset)
 #define NEXT(obj,offset) xbt_swag_getNext(obj,offset)
@@ -22,13 +22,18 @@
 
 xbt_swag_t xbt_swag_new(size_t offset)
 {
-  xbt_swag_t swag = calloc(1, sizeof(s_xbt_swag_t));
+  xbt_swag_t swag = xbt_new0(s_xbt_swag_t,1);
 
   swag->offset = offset;
 
   return swag;
 }
 
+void xbt_swag_init(xbt_swag_t swag, size_t offset)
+{
+  swag->offset = offset;
+}
+
 void xbt_swag_insert(void *obj, xbt_swag_t swag)
 {
   (swag->count)++;
@@ -41,29 +46,20 @@ void xbt_swag_insert(void *obj, xbt_swag_t swag)
   PREV(obj, swag->offset) = swag->tail;
   NEXT(PREV(obj, swag->offset), swag->offset) = obj;
 
-/*   new->prev = l->tail; */
-/*   new->prev->next = new; */
-
   swag->tail = obj;
 }
 
-void xbt_swag_extract(void *obj, xbt_swag_t swag)
+void *xbt_swag_extract(void *obj, xbt_swag_t swag)
 {
   size_t offset = swag->offset;
 
+  if (!obj) return NULL;
   if (swag->head == swag->tail) {	/* special case */
-    if (swag->head != obj) {
-      fprintf(stderr,
-	      "Tried to remove an object that was not in this swag\n");
-      abort();
-    }
+    if (swag->head != obj) /* Trying to remove an object that was not in this swag */
+      return NULL;
     swag->head = NULL;
     swag->tail = NULL;
-    (swag->count)--;
-    return;
-  }
-
-  if (obj == swag->head) {	/* It's the head */
+  } else if (obj == swag->head) {	/* It's the head */
     swag->head = NEXT(obj, offset);
     PREV(swag->head, offset) = NULL;
     NEXT(obj, offset) = NULL;
@@ -77,6 +73,7 @@ void xbt_swag_extract(void *obj, xbt_swag_t swag)
     PREV(obj, offset) = NEXT(obj, offset) = NULL;
   }
   (swag->count)--;
+  return obj;
 }
 
 int xbt_swag_size(xbt_swag_t swag)
-- 
2.20.1