1 files changed, 53 insertions, 0 deletions
diff --git a/unix/boot/spp/rpp/ratlibr/dsfree.r b/unix/boot/spp/rpp/ratlibr/dsfree.r
new file mode 100644
index 00000000..34cd7e55
--- /dev/null
+++ b/unix/boot/spp/rpp/ratlibr/dsfree.r
@@ -0,0 +1,53 @@
+include	defs
+
+# dsfree --- return a block of storage to the available space list
+
+   subroutine dsfree (block)
+   pointer block
+
+   DS_DECL(Mem, 1)
+
+   pointer p0, p, q
+
+   integer n, junk
+
+   character con (10)
+
+   p0 = block - DS_OHEAD
+   n = Mem (p0 + DS_SIZE)
+   q = DS_AVAIL
+
+   repeat {
+      p = Mem (q + DS_LINK)
+      if (p == LAMBDA | p > p0)
+	 break
+      q = p
+      }
+
+   if (q + Mem (q + DS_SIZE) > p0) {
+      call remark ("in dsfree:	attempt to free unallocated block.")
+      call remark ("type 'c' to continue.")
+      junk = getlin (con, STDIN)
+      if (con (1) != LETC & con (1) != BIGC)
+	 call endst
+      return	  # do not attempt to free the block
+      }
+
+   if (p0 + n == p & p != LAMBDA) {
+      n = n + Mem (p + DS_SIZE)
+      Mem (p0 + DS_LINK) = Mem (p + DS_LINK)
+      }
+   else
+      Mem (p0 + DS_LINK) = p
+
+   if (q + Mem (q + DS_SIZE) == p0) {
+      Mem (q + DS_SIZE) = Mem (q + DS_SIZE) + n
+      Mem (q + DS_LINK) = Mem (p0 + DS_LINK)
+      }
+   else {
+      Mem (q + DS_LINK) = p0
+      Mem (p0 + DS_SIZE) = n
+      }
+
+   return
+   end