(in-package "SB!IMPL")
-;;; FIXME Not the most sensible way to do this: we could just use
-;;; LOCK ADD, given that we don't need the old version. This will
-;;; do until we get around to writing new VOPs
-;;; FIXME in fact we're not SMP-safe without LOCK anyway, but
-;;; this will do us for UP systems
-
(defmacro atomic-incf/symbol (symbol-name &optional (delta 1))
#!-sb-thread
`(incf ,symbol-name ,delta)
(declare (optimize (safety 0) (speed 3)))
(sb!vm::locked-symbol-global-value-add ',symbol-name ,delta)))
-(defmacro without-gcing (&rest body)
+(defvar *gc-inhibit*) ; initialized in cold init
+
+;;; When the dynamic usage increases beyond this amount, the system
+;;; notes that a garbage collection needs to occur by setting
+;;; *GC-PENDING* to T. It starts out as NIL meaning nobody has figured
+;;; out what it should be yet.
+(defvar *gc-pending* nil)
+
+#!+sb-thread
+(defvar *stop-for-gc-pending* nil)
+
+(defmacro without-gcing (&body body)
#!+sb-doc
- "Executes the forms in the body without doing a garbage collection."
- `(unwind-protect
- (progn
- (atomic-incf/symbol *gc-inhibit*)
- ,@body)
- (atomic-incf/symbol *gc-inhibit* -1)
- (when (and *need-to-collect-garbage* (zerop *gc-inhibit*))
- (sub-gc))))
+ "Executes the forms in the body without doing a garbage collection. It
+inhibits both automatically and explicitly triggered collections. Finally,
+upon leaving the BODY if gc is not inhibited it runs the pending gc.
+Similarly, if gc is triggered in another thread then it waits until gc is
+enabled in this thread.
+
+Implies SB-SYS:WITHOUT-INTERRUPTS for BODY, and causes any nested
+SB-SYS:WITH-INTERRUPTS to signal a warning during execution of the BODY.
+
+Should be used with great care, and not at all in multithreaded application
+code: Any locks that are ever acquired while GC is inhibited need to be always
+held with GC inhibited to prevent deadlocks: if T1 holds the lock and is
+stopped for GC while T2 is waiting for the lock inside WITHOUT-GCING the
+system will be deadlocked. Since SBCL does not currently document its internal
+locks, application code can never be certain that this invariant is
+maintained."
+ (with-unique-names (without-gcing-body)
+ `(flet ((,without-gcing-body ()
+ ,@body))
+ (if *gc-inhibit*
+ (,without-gcing-body)
+ (without-interrupts
+ ;; We need to disable interrupts before disabling GC, so that
+ ;; signal handlers using locks don't accidentally try to grab
+ ;; them with GC inhibited.
+ ;;
+ ;; It would be nice to implement this with just a single UWP, but
+ ;; unfortunately it seems that it cannot be done: the naive
+ ;; solution of binding both *INTERRUPTS-ENABLED* and
+ ;; *GC-INHIBIT*, and checking for both pending GC and interrupts
+ ;; in the cleanup breaks if we have a GC pending, but no
+ ;; interrupts, and we receive an asynch unwind while checking for
+ ;; the pending GC: we unwind before handling the pending GC, and
+ ;; will be left running with further GCs blocked due to the GC
+ ;; pending flag.
+ (unwind-protect
+ (let ((*gc-inhibit* t))
+ (,without-gcing-body))
+ (when (or *gc-pending* #!+sb-thread *stop-for-gc-pending*)
+ (sb!unix::receive-pending-interrupt))))))))
\f
;;; EOF-OR-LOSE is a useful macro that handles EOF.
(let ((svar (gensym)))
`(let ((,svar ,stream))
(cond ((null ,svar) *standard-input*)
- ((eq ,svar t) *terminal-io*)
- (T ,@(when check-type `((enforce-type ,svar ,check-type)))
- #!+high-security
- (unless (input-stream-p ,svar)
- (error 'simple-type-error
- :datum ,svar
- :expected-type '(satisfies input-stream-p)
- :format-control "~S isn't an input stream"
- :format-arguments (list ,svar)))
- ,svar)))))
+ ((eq ,svar t) *terminal-io*)
+ (t ,@(when check-type `((enforce-type ,svar ,check-type))) ;
+ #!+high-security
+ (unless (input-stream-p ,svar)
+ (error 'simple-type-error
+ :datum ,svar
+ :expected-type '(satisfies input-stream-p)
+ :format-control "~S isn't an input stream"
+ :format-arguments (list ,svar)))
+ ,svar)))))
(defmacro out-synonym-of (stream &optional check-type)
(let ((svar (gensym)))
`(let ((,svar ,stream))
(cond ((null ,svar) *standard-output*)
- ((eq ,svar t) *terminal-io*)
- (T ,@(when check-type `((check-type ,svar ,check-type)))
- #!+high-security
- (unless (output-stream-p ,svar)
- (error 'simple-type-error
- :datum ,svar
- :expected-type '(satisfies output-stream-p)
- :format-control "~S isn't an output stream."
- :format-arguments (list ,svar)))
- ,svar)))))
+ ((eq ,svar t) *terminal-io*)
+ (t ,@(when check-type `((check-type ,svar ,check-type)))
+ #!+high-security
+ (unless (output-stream-p ,svar)
+ (error 'simple-type-error
+ :datum ,svar
+ :expected-type '(satisfies output-stream-p)
+ :format-control "~S isn't an output stream."
+ :format-arguments (list ,svar)))
+ ,svar)))))
;;; WITH-mumble-STREAM calls the function in the given SLOT of the
;;; STREAM with the ARGS for ANSI-STREAMs, or the FUNCTION with the
(defmacro with-in-stream (stream (slot &rest args) &optional stream-dispatch)
`(let ((stream (in-synonym-of ,stream)))
,(if stream-dispatch
- `(if (ansi-stream-p stream)
- (funcall (,slot stream) stream ,@args)
- ,@(when stream-dispatch
- `(,(destructuring-bind (function &rest args) stream-dispatch
- `(,function stream ,@args)))))
- `(funcall (,slot stream) stream ,@args))))
+ `(if (ansi-stream-p stream)
+ (funcall (,slot stream) stream ,@args)
+ ,@(when stream-dispatch
+ `(,(destructuring-bind (function &rest args) stream-dispatch
+ `(,function stream ,@args)))))
+ `(funcall (,slot stream) stream ,@args))))
-(defmacro with-out-stream (stream (slot &rest args) &optional stream-dispatch)
- `(let ((stream (out-synonym-of ,stream)))
+(defmacro with-out-stream/no-synonym (stream (slot &rest args) &optional stream-dispatch)
+ `(let ((stream ,stream))
,(if stream-dispatch
- `(if (ansi-stream-p stream)
- (funcall (,slot stream) stream ,@args)
- ,@(when stream-dispatch
- `(,(destructuring-bind (function &rest args) stream-dispatch
- `(,function stream ,@args)))))
- `(funcall (,slot stream) stream ,@args))))
+ `(if (ansi-stream-p stream)
+ (funcall (,slot stream) stream ,@args)
+ ,@(when stream-dispatch
+ `(,(destructuring-bind (function &rest args) stream-dispatch
+ `(,function stream ,@args)))))
+ `(funcall (,slot stream) stream ,@args))))
+
+(defmacro with-out-stream (stream (slot &rest args) &optional stream-dispatch)
+ `(with-out-stream/no-synonym (out-synonym-of ,stream)
+ (,slot ,@args) ,stream-dispatch))
+
\f
;;;; These are hacks to make the reader win.
;;; This macro sets up some local vars for use by the
;;; FAST-READ-CHAR macro within the enclosed lexical scope. The stream
;;; is assumed to be a ANSI-STREAM.
+;;;
+;;; KLUDGE: Some functions (e.g. ANSI-STREAM-READ-LINE) use these variables
+;;; directly, instead of indirecting through FAST-READ-CHAR.
(defmacro prepare-for-fast-read-char (stream &body forms)
`(let* ((%frc-stream% ,stream)
- (%frc-method% (ansi-stream-in %frc-stream%))
- (%frc-buffer% (ansi-stream-in-buffer %frc-stream%))
- (%frc-index% (ansi-stream-in-index %frc-stream%)))
+ (%frc-method% (ansi-stream-in %frc-stream%))
+ (%frc-buffer% (ansi-stream-cin-buffer %frc-stream%))
+ (%frc-index% (ansi-stream-in-index %frc-stream%)))
(declare (type index %frc-index%)
- (type ansi-stream %frc-stream%))
+ (type ansi-stream %frc-stream%))
,@forms))
;;; This macro must be called after one is done with FAST-READ-CHAR
`(setf (ansi-stream-in-index %frc-stream%) %frc-index%))
;;; a macro with the same calling convention as READ-CHAR, to be used
-;;; within the scope of a PREPARE-FOR-FAST-READ-CHAR
+;;; within the scope of a PREPARE-FOR-FAST-READ-CHAR.
(defmacro fast-read-char (&optional (eof-error-p t) (eof-value ()))
`(cond
((not %frc-buffer%)
(funcall %frc-method% %frc-stream% ,eof-error-p ,eof-value))
((= %frc-index% +ansi-stream-in-buffer-length+)
(prog1 (fast-read-char-refill %frc-stream% ,eof-error-p ,eof-value)
- (setq %frc-index% (ansi-stream-in-index %frc-stream%))))
+ (setq %frc-index% (ansi-stream-in-index %frc-stream%))))
(t
- (prog1 (code-char (aref %frc-buffer% %frc-index%))
- (incf %frc-index%)))))
+ (prog1 (aref %frc-buffer% %frc-index%)
+ (incf %frc-index%)))))
;;;; And these for the fasloader...
;;; for the FAST-READ-CHAR stuff) -- WHN 19990825
(defmacro prepare-for-fast-read-byte (stream &body forms)
`(let* ((%frc-stream% ,stream)
- (%frc-method% (ansi-stream-bin %frc-stream%))
- (%frc-buffer% (ansi-stream-in-buffer %frc-stream%))
- (%frc-index% (ansi-stream-in-index %frc-stream%)))
+ (%frc-method% (ansi-stream-bin %frc-stream%))
+ (%frc-buffer% (ansi-stream-in-buffer %frc-stream%))
+ (%frc-index% (ansi-stream-in-index %frc-stream%)))
(declare (type index %frc-index%)
- (type ansi-stream %frc-stream%))
+ (type ansi-stream %frc-stream%))
,@forms))
;;; Similar to fast-read-char, but we use a different refill routine & don't
(funcall %frc-method% %frc-stream% ,eof-error-p ,eof-value))
((= %frc-index% +ansi-stream-in-buffer-length+)
(prog1 (fast-read-byte-refill %frc-stream% ,eof-error-p ,eof-value)
- (setq %frc-index% (ansi-stream-in-index %frc-stream%))))
+ (setq %frc-index% (ansi-stream-in-index %frc-stream%))))
(t
(prog1 (aref %frc-buffer% %frc-index%)
- (incf %frc-index%))))))
+ (incf %frc-index%))))))
(defmacro done-with-fast-read-byte ()
`(done-with-fast-read-char))
projects / sbcl.git / blobdiff