0.8.3.39:

[sbcl.git] / src / code / gc.lisp

diff --git a/src/code/gc.lisp b/src/code/gc.lisp
index f3daccc..0e60184 100644 (file)
--- a/src/code/gc.lisp
+++ b/src/code/gc.lisp
@@ -143,19 +143,14 @@ and submit it as a patch."
 (defvar *before-gc-hooks* nil ; actually initialized in cold init
   #!+sb-doc
   "A list of functions that are called before garbage collection occurs.
-  The functions should take no arguments.")
+  The functions are run with interrupts disabled and all other threads
+  paused.  They should take no arguments.")
 
 (defvar *after-gc-hooks* nil ; actually initialized in cold init
   #!+sb-doc
   "A list of functions that are called after garbage collection occurs.
-  The functions should take no arguments.")
-
-(defvar *gc-notify-stream* nil ; (actually initialized in cold init)
-  #!+sb-doc
-  "When non-NIL, this must be a STREAM; and the functions bound to
-  *GC-NOTIFY-BEFORE* and *GC-NOTIFY-AFTER* are called with the
-  STREAM value before and after a garbage collection occurs
-  respectively.")
+  The functions are run with interrupts disabled and all other threads
+  paused.  They should take no arguments.")
 
 (defvar *gc-run-time* 0
   #!+sb-doc
@@ -204,9 +199,14 @@ and submit it as a patch."
   (#!+gencgc last-gen #!-gencgc ignore sb!alien:int))
 
 #!+sb-thread
-(def-c-var-frob gc-thread-pid "gc_thread_pid")
+(progn
+  (sb!alien:define-alien-routine gc-stop-the-world sb!alien:void)
+  (sb!alien:define-alien-routine gc-start-the-world sb!alien:void))
+#!-sb-thread
+(progn
+  (defun gc-stop-the-world ())
+  (defun gc-start-the-world ()))
 
-       
 \f
 ;;;; SUB-GC
 
@@ -220,7 +220,8 @@ and submit it as a patch."
 
 ;;; SUB-GC does a garbage collection.  This is called from three places:
 ;;; (1) The C runtime will call here when it detects that we've consed 
-;;;     enough to exceed the gc trigger threshold
+;;;     enough to exceed the gc trigger threshold.  This is done in
+;;;     alloc() for gencgc or interrupt_maybe_gc() for cheneygc
 ;;; (2) The user may request a collection using GC, below
 ;;; (3) At the end of a WITHOUT-GCING section, we are called if
 ;;;     *NEED-TO-COLLECT-GARBAGE* is true
@@ -232,37 +233,27 @@ and submit it as a patch."
 
 ;;; For GENCGC all generations < GEN will be GC'ed.
 
-#!+sb-thread
-(defun sub-gc (&key (gen 0) &aux (pre-gc-dynamic-usage (dynamic-usage)))
-  (setf *need-to-collect-garbage* t)
-  (when (zerop *gc-inhibit*)
-    (setf (sb!alien:extern-alien "maybe_gc_pending" (sb!alien:unsigned 32))
-         (1+ gen))
-    (if (zerop (sb!alien:extern-alien "stop_the_world" (sb!alien:unsigned 32)))
-       (sb!unix:unix-kill (gc-thread-pid) :SIGALRM))
-    (loop
-     (when (zerop
-           (sb!alien:extern-alien "maybe_gc_pending" (sb!alien:unsigned 32)))
-       (return nil)))
-    (incf *n-bytes-freed-or-purified*
-         (max 0 (- pre-gc-dynamic-usage (dynamic-usage))))
-    (setf *need-to-collect-garbage* nil)
-    (scrub-control-stack))
-  (values))
-
-#!-sb-thread
 (defvar *already-in-gc* nil "System is running SUB-GC")
-#!-sb-thread
+(defvar *gc-mutex* (sb!thread:make-mutex :name "GC Mutex"))
+
 (defun sub-gc (&key (gen 0) &aux (pre-gc-dynamic-usage (dynamic-usage)))
   (when *already-in-gc* (return-from sub-gc nil))
   (setf *need-to-collect-garbage* t)
   (when (zerop *gc-inhibit*)
-    (let ((*already-in-gc* t))
-      (without-interrupts (collect-garbage gen))
-      (incf *n-bytes-freed-or-purified*
-           (max 0 (- pre-gc-dynamic-usage (dynamic-usage))))
-      (setf *need-to-collect-garbage* nil))
-    (scrub-control-stack))
+    (sb!thread:with-recursive-lock (*gc-mutex*)
+      (let ((*already-in-gc* t))
+       (without-interrupts
+        (gc-stop-the-world)
+        (dolist (h *before-gc-hooks*)
+          (carefully-funcall h))
+        (collect-garbage gen)
+        (incf *n-bytes-freed-or-purified*
+              (max 0 (- pre-gc-dynamic-usage (dynamic-usage))))
+        (setf *need-to-collect-garbage* nil)
+        (dolist (h *after-gc-hooks*)
+          (carefully-funcall h))
+        (gc-start-the-world)))
+      (scrub-control-stack)))
   (values))