+;;;; unithread stub support for threads in the target machine
+
+;;;; This software is part of the SBCL system. See the README file for
+;;;; more information.
+;;;;
+;;;; This software is derived from the CMU CL system, which was
+;;;; written at Carnegie Mellon University and released into the
+;;;; public domain. The software is in the public domain and is
+;;;; provided with absolutely no warranty. See the COPYING and CREDITS
+;;;; files for more information.
+
(in-package "SB!THREAD")
-#-sb-fluid (declaim (inline sb!vm::current-thread-offset-sap))
-(defun sb!vm::current-thread-offset-sap (n)
+;;; used bu debug-int.lisp to access interrupt contexts
+#!-sb-fluid (declaim (inline sb!vm::current-thread-offset-sap))
+(defun sb!vm::current-thread-offset-sap (n)
(declare (type (unsigned-byte 27) n))
- (sb!sys:sap-ref-sap (alien-sap (extern-alien "all_threads" (* t)))
- (* n 4)))
+ (sb!sys:sap-ref-sap (alien-sap (extern-alien "all_threads" (* t)))
+ (* n sb!vm:n-word-bytes)))
-(defun current-thread-id ()
- (sb!sys:sap-int
- (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot)))
-
-;;;; queues, locks
+;;;; queues, locks
;; spinlocks use 0 as "free" value: higher-level locks use NIL
-(defun get-spinlock (lock offset new-value) )
+(defun get-spinlock (lock offset new-value)
+ (declare (ignore lock offset new-value)))
(defmacro with-spinlock ((queue) &body body)
+ (declare (ignore queue))
`(progn ,@body))
;;;; the higher-level locking operations are based on waitqueues
(defstruct waitqueue
- (name nil :type (or null simple-base-string))
+ (name nil :type (or null simple-string))
(lock 0)
(data nil))
(defstruct (mutex (:include waitqueue))
(value nil))
-#+nil
-(defun wait-on-queue (queue &optional lock)
- (let ((pid (current-thread-id)))
- ;; FIXME what should happen if we get interrupted when we've blocked
- ;; the sigcont? For that matter, can we get interrupted?
- (block-sigcont)
- (when lock (release-mutex lock))
- (get-spinlock queue 2 pid)
- (pushnew pid (waitqueue-data queue))
- (setf (waitqueue-lock queue) 0)
- (unblock-sigcont-and-sleep)))
-
-#+nil
-(defun dequeue (queue)
- (let ((pid (current-thread-id)))
- (get-spinlock queue 2 pid)
- (setf (waitqueue-data queue)
- (delete pid (waitqueue-data queue)))
- (setf (waitqueue-lock queue) 0)))
-
-#+nil
-(defun signal-queue-head (queue)
- (let ((pid (current-thread-id)))
- (get-spinlock queue 2 pid)
- (let ((h (car (waitqueue-data queue))))
- (setf (waitqueue-lock queue) 0)
- (when h
- (sb!unix:unix-kill h :sigcont)))))
-
;;;; mutex
-#+nil
(defun get-mutex (lock &optional new-value (wait-p t))
(declare (type mutex lock))
- (let ((pid (current-thread-id)))
- (unless new-value (setf new-value pid))
- (assert (not (eql new-value (mutex-value lock))))
- (loop
- (unless
- ;; args are object slot-num old-value new-value
- (sb!vm::%instance-set-conditional lock 4 nil new-value)
- (dequeue lock)
- (return t))
- (unless wait-p (return nil))
- (wait-on-queue lock nil))))
-
-#+nil
-(defun release-mutex (lock &optional (new-value nil))
+ (let ((old-value (mutex-value lock)))
+ (when (and old-value wait-p)
+ (error "In unithread mode, mutex ~S was requested with WAIT-P ~S and ~
+ new-value ~S, but has already been acquired (with value ~S)."
+ lock wait-p new-value old-value))
+ (setf (mutex-value lock) new-value)
+ t))
+
+(defun release-mutex (lock)
(declare (type mutex lock))
- (let ((old-value (mutex-value lock))
- (t1 nil))
- (loop
- (unless
- ;; args are object slot-num old-value new-value
- (eql old-value
- (setf t1
- (sb!vm::%instance-set-conditional lock 4 old-value new-value)))
- (signal-queue-head lock)
- (return t))
- (setf old-value t1))))
-
-(defmacro with-mutex ((mutex &key value (wait-p t)) &body body)
- (declare (ignore mutex value wait-p))
- `(progn ,@body))
-
-;;; what's the best thing to do with these on unithread?
-#+NIl
-(defun condition-wait (queue lock)
- "Atomically release LOCK and enqueue ourselves on QUEUE. Another
-thread may subsequently notify us using CONDITION-NOTIFY, at which
-time we reacquire LOCK and return to the caller."
- (unwind-protect
- (wait-on-queue queue lock)
- ;; If we are interrupted while waiting, we should do these things
- ;; before returning. Ideally, in the case of an unhandled signal,
- ;; we should do them before entering the debugger, but this is
- ;; better than nothing.
- (dequeue queue)
- (get-mutex lock)))
-
-#+nil
-(defun condition-notify (queue)
- "Notify one of the processes waiting on QUEUE"
- (signal-queue-head queue))
-
+ (setf (mutex-value lock) nil))
-;;;; multiple independent listeners
-(defvar *session-lock* nil)
+;; FIXME need suitable stub or ERROR-signaling definitions for
+;; condition-wait (queue lock)
+;; condition-notify (queue)
;;;; job control
-(defun debugger-wait-until-foreground-thread (stream) t)
+(defun init-job-control () t)
+(defun debugger-wait-until-foreground-thread (stream)
+ (declare (ignore stream))
+ t)
+(defun get-foreground () t)
+(defun release-foreground (&optional next)
+ (declare (ignore next))
+ t)
+(defun terminate-session ())