Changeset 14553

Timestamp:

Jan 4, 2011, 9:41:56 AM (14 years ago)

Author:

gz

Message:

Make *GENSYM-COUNTER* global. This means (GENSYM) will generate
globally unique pnames, though it also means multi-threaded code that
explicitly modifies *GENSYM-COUNTER* may need to do appropriate locking
or binding to achieve whatever effect it is hoping to achieve. See
ticket:799 for discussion.

Location:

trunk/source/level-1

Files:

• l1-aprims.lisp (modified) (1 diff)
• l1-utils.lisp (modified) (2 diffs)

trunk/source/level-1/l1-aprims.lisp

@@ -55 +55 @@
 
 (def-standard-initial-binding *package*)
-(def-standard-initial-binding *gensym-counter* 0)
 (def-standard-initial-binding *random-state* (initial-random-state))
 (def-standard-initial-binding *whostate* "Reset")

trunk/source/level-1/l1-utils.lisp

@@ -755 +755 @@
 ;;;;;;;;; VALUE BINDING Functions
 
+;; Lock used only to make sure calls to GENSYM don't step on each other.  Users who
+;; modify *gensym-counter* in multi-threaded apps will need to do their own locking.
+(defparameter *gensym-lock* (make-lock))
+
 (defun gensym (&optional (string-or-integer nil string-or-integer-p))
   "Creates a new uninterned symbol whose name is a prefix string (defaults
@@ -769 +773 @@
         (string (setq prefix (ensure-simple-string string-or-integer)))))
     (unless counter
-      (setq *gensym-counter* (1+ (setq counter *gensym-counter*))))
+      (with-lock-grabbed (*gensym-lock*)
+        (setq *gensym-counter* (1+ (setq counter *gensym-counter*)))))
     (make-symbol (%str-cat prefix (%integer-to-string counter)))))