X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fexhaust.lisp;h=7de2f007085623ee139b3a457b7c35ae4f4c4c55;hb=ca267caa3bdb897a93a1e69ae7300ba3ba5d391f;hp=18792451a9ced4b9e73333a4bbe221bfd20e66b0;hpb=ec2616d216958a608581802c47496c0194478dc8;p=sbcl.git

diff --git a/src/code/exhaust.lisp b/src/code/exhaust.lisp
index 1879245..7de2f00 100644
--- a/src/code/exhaust.lisp
+++ b/src/code/exhaust.lisp
@@ -1,4 +1,5 @@
-;;;; detecting and handling exhaustion of memory (stack or heap)
+;;;; detecting and handling exhaustion of fundamental system resources
+;;;; (stack or heap)
 
 ;;;; This software is part of the SBCL system. See the README file for
 ;;;; more information.
@@ -10,60 +11,11 @@
 ;;;; files for more information.
 
 (in-package "SB!KERNEL")
+(define-alien-routine ("protect_control_stack_guard_page"
+		       %protect-control-stack-guard-page)
+    sb!alien:int (thread-id sb!alien:int) (protect-p sb!alien:int))
+(defun protect-control-stack-guard-page (n)
+  (%protect-control-stack-guard-page 
+   (sb!thread:current-thread-id) (if n 1 0)))
 
-;;; A native address on a 4-byte boundary can be thought of (and
-;;; passed around in Lisp code as) a FIXNUM. This function converts
-;;; from a byte address represented as an unsigned integer to such
-;;; a FIXNUM.
-;;;
-;;; FIXME: There should be some better place for this definition to
-;;; go. (Or a redundant definition might already exist. Especially
-;;; since this is essentially just a type pun, so there might be some
-;;; VOP or something which'd do it for us.)
-(eval-when (:compile-toplevel :load-toplevel :execute)
-  (defun native-address-encoded-as-fixnum (native-address)
-    (declare (type unsigned-byte native-address))
-    (aver (zerop (logand native-address 3)))
-    (let* (;; naive encoding
-	   (first-try (ash native-address -2))
-	   ;; final encoding
-	   (second-try 
-	    (if (<= first-try sb!xc:most-positive-fixnum)
-		;; looks good
-		first-try
-		;; When the naive encoding fails to make a FIXNUM
-		;; because the sign is wrong, subtracting *T-M-P-F*
-		;; should fix it. 
-		(- first-try sb!xc:most-positive-fixnum))))
-      (aver (<= second-try sb!xc:most-positive-fixnum))
-      second-try)))
 
-;;; a FIXNUM, to be interpreted as a native pointer, which serves
-;;; as a boundary to catch stack overflow
-;;;
-;;; When stack overflow is detected, this is to be bound to a new
-;;; value (allowing some more space for error handling) around the
-;;; call to ERROR.
-;;;
-;;; FIXME: Maybe (probably?) this should be in SB!VM. And maybe the
-;;; size of the buffer zone should be set in src/compiler/cpu/parms.lisp
-;;; instead of constantly 1Mb for all CPU architectures?
-(defvar *stack-exhaustion*
-  ;; (initialized in cold init)
-  )
-(defun !exhaust-cold-init ()
-  (setf *stack-exhaustion*
-	#.(native-address-encoded-as-fixnum
-	   #!+stack-grows-downward (+ sb!vm:control-stack-start (expt 2 20))
-	   #!+stack-grows-upward (- sb!vm:control-stack-end (expt 2 20)))))
-  
-;;; FIXME: Even though this is only called when (> SAFETY (MAX SPEED SPACE))
-;;; it's still annoyingly wasteful for it to be a full function call.
-;;; It should probably be a VOP calling an assembly routine or something
-;;; like that.
-(defun %detect-stack-exhaustion ()
-  ;; FIXME: Check the stack pointer against *STACK-EXHAUSTION*, and if
-  ;; out of range signal an error (in a context where *S-E* has been
-  ;; rebound to give some space to let error handling code do its
-  ;; thing without new exhaustion problems).
-  (values))