Syn68k from an svn export

runtime/deathqueue.c

@@ -0,0 +1,49 @@
+#include "deathqueue.h"
+
+
+Block *death_queue_head = NULL, *death_queue_tail = NULL;
+
+
+/* Appends a block to the end of the doubly-linked death queue. */
+void
+death_queue_enqueue (Block *b)
+{
+  b->death_queue_prev = death_queue_tail;
+  b->death_queue_next = NULL;
+
+  if (death_queue_tail == NULL)
+    death_queue_head = b;
+  else
+    death_queue_tail->death_queue_next = b;
+
+  death_queue_tail = b;
+}
+
+
+/* Removes a block from the end of the doubly-linked death queue. */
+void
+death_queue_dequeue (Block *b)
+{
+  Block *p, *n;
+
+  p = b->death_queue_prev;
+  n = b->death_queue_next;
+
+  if (p == NULL)
+    {
+      if (death_queue_head == b)  /* Verify this just to be safe. */
+	death_queue_head = n;
+    }
+  else
+    p->death_queue_next = n;
+
+  if (n == NULL)
+    {
+      if (death_queue_tail == b)  /* Verify this just to be safe. */
+	death_queue_tail = p;
+    }
+  else
+    n->death_queue_prev = p;
+
+  b->death_queue_prev = b->death_queue_next = NULL;
+}