+;;;; 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")
;;; FIXME it would be good to define what a thread id is or isn't (our
;;; current assumption is that it's a fixnum). It so happens that on
;;; Linux it's a pid, but it might not be on posix thread implementations
-(sb!alien::define-alien-routine ("create_thread" %create-thread)
- sb!alien:unsigned-long
- (lisp-fun-address sb!alien:unsigned-long))
+(define-alien-routine ("create_thread" %create-thread)
+ unsigned-long
+ (lisp-fun-address unsigned-long))
-(sb!alien::define-alien-routine "signal_thread_to_dequeue"
- sb!alien:unsigned-int
- (thread-pid sb!alien:unsigned-long))
+(define-alien-routine "signal_thread_to_dequeue"
+ unsigned-int
+ (thread-id unsigned-long))
(defvar *session* nil)
-(defun make-thread (function)
- (let* ((real-function (coerce function 'function))
- (tid
- (%create-thread
- (sb!kernel:get-lisp-obj-address
- (lambda ()
- ;; in time we'll move some of the binding presently done in C
- ;; here too
- (let ((sb!kernel::*restart-clusters* nil)
- (sb!impl::*descriptor-handlers* nil) ; serve-event
- (sb!impl::*available-buffers* nil)) ;for fd-stream
- ;; can't use handling-end-of-the-world, because that flushes
- ;; output streams, and we don't necessarily have any (or we
- ;; could be sharing them)
- (sb!sys:enable-interrupt sb!unix:sigint :ignore)
- (sb!unix:unix-exit
- (catch 'sb!impl::%end-of-the-world
- (with-simple-restart
- (destroy-thread
- (format nil "~~@<Destroy this thread (~A)~~@:>"
- (current-thread-id)))
- (funcall real-function))
- 0))))))))
- (with-mutex ((session-lock *session*))
- (pushnew tid (session-threads *session*)))
- tid))
-
-;;; Really, you don't want to use these: they'll get into trouble with
-;;; garbage collection. Use a lock or a waitqueue instead
-(defun suspend-thread (thread-id)
- (sb!unix:unix-kill thread-id sb!unix:sigstop))
-(defun resume-thread (thread-id)
- (sb!unix:unix-kill thread-id sb!unix:sigcont))
-;;; Note warning about cleanup forms
-(defun destroy-thread (thread-id)
- "Destroy the thread identified by THREAD-ID abruptly, without running cleanup forms"
- (sb!unix:unix-kill thread-id sb!unix:sigterm)
- ;; may have been stopped for some reason, so now wake it up to
- ;; deliver the TERM
- (sb!unix:unix-kill thread-id sb!unix:sigcont))
-
-
-;;; a moderate degree of care is expected for use of interrupt-thread,
-;;; due to its nature: if you interrupt a thread that was holding
-;;; important locks then do something that turns out to need those
-;;; locks, you probably won't like the effect. Used with thought
-;;; though, it's a good deal gentler than the last-resort functions above
-
-(defun interrupt-thread (thread function)
- "Interrupt THREAD and make it run FUNCTION. "
- (sb!unix::syscall* ("interrupt_thread"
- sb!alien:unsigned-long sb!alien:unsigned-long)
- thread
- thread (sb!kernel:get-lisp-obj-address
- (coerce function 'function))))
-(defun terminate-thread (thread-id)
- "Terminate the thread identified by THREAD-ID, by causing it to run
-SB-EXT:QUIT - the usual cleanup forms will be evaluated"
- (interrupt-thread thread-id 'sb!ext:quit))
-
-(declaim (inline current-thread-id))
-(defun current-thread-id ()
- (logand
- (sb!sys:sap-int
- (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot))
- ;; KLUDGE pids are 16 bit really. Avoid boxing the return value
- (1- (ash 1 16))))
-
-;;;; iterate over the in-memory threads
-
-(defun mapcar-threads (function)
- "Call FUNCTION once for each known thread, giving it the thread structure as argument"
- (let ((function (coerce function 'function)))
- (loop for thread = (alien-sap (extern-alien "all_threads" (* t)))
- then (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot))
- until (sb!sys:sap= thread (sb!sys:int-sap 0))
- collect (funcall function thread))))
-
;;;; queues, locks
;; spinlocks use 0 as "free" value: higher-level locks use NIL
(sb!alien:define-alien-routine
"futex_wake" int (word unsigned-long) (n unsigned-long))
+
;;; this should only be called while holding the queue spinlock.
;;; it releases the spinlock before sleeping
(defun wait-on-queue (queue &optional lock)
(setf (mutex-value lock) nil)
(futex-wake (mutex-value-address lock) 1))
-
-(defmacro with-mutex ((mutex &key value (wait-p t)) &body body)
- (with-unique-names (got)
- `(let ((,got (get-mutex ,mutex ,value ,wait-p)))
- (when ,got
- (unwind-protect
- (progn ,@body)
- (release-mutex ,mutex))))))
-
-
;;;; condition variables
(defun condition-wait (queue lock)
(fdefinition 'condition-notify) #'condition-notify/futex)
t))
+(defun make-thread (function)
+ (let* ((real-function (coerce function 'function))
+ (tid
+ (%create-thread
+ (sb!kernel:get-lisp-obj-address
+ (lambda ()
+ ;; in time we'll move some of the binding presently done in C
+ ;; here too
+ (let ((sb!kernel::*restart-clusters* nil)
+ (sb!impl::*descriptor-handlers* nil) ; serve-event
+ (sb!impl::*available-buffers* nil)) ;for fd-stream
+ ;; can't use handling-end-of-the-world, because that flushes
+ ;; output streams, and we don't necessarily have any (or we
+ ;; could be sharing them)
+ (sb!sys:enable-interrupt sb!unix:sigint :ignore)
+ (sb!unix:unix-exit
+ (catch 'sb!impl::%end-of-the-world
+ (with-simple-restart
+ (destroy-thread
+ (format nil "~~@<Destroy this thread (~A)~~@:>"
+ (current-thread-id)))
+ (funcall real-function))
+ 0))))))))
+ (with-mutex ((session-lock *session*))
+ (pushnew tid (session-threads *session*)))
+ tid))
+
+;;; Really, you don't want to use these: they'll get into trouble with
+;;; garbage collection. Use a lock or a waitqueue instead
+(defun suspend-thread (thread-id)
+ (sb!unix:unix-kill thread-id sb!unix:sigstop))
+(defun resume-thread (thread-id)
+ (sb!unix:unix-kill thread-id sb!unix:sigcont))
+;;; Note warning about cleanup forms
+(defun destroy-thread (thread-id)
+ "Destroy the thread identified by THREAD-ID abruptly, without running cleanup forms"
+ (sb!unix:unix-kill thread-id sb!unix:sigterm)
+ ;; may have been stopped for some reason, so now wake it up to
+ ;; deliver the TERM
+ (sb!unix:unix-kill thread-id sb!unix:sigcont))
+
+
+
+
+;;; a moderate degree of care is expected for use of interrupt-thread,
+;;; due to its nature: if you interrupt a thread that was holding
+;;; important locks then do something that turns out to need those
+;;; locks, you probably won't like the effect. Used with thought
+;;; though, it's a good deal gentler than the last-resort functions above
+
+(defun interrupt-thread (thread function)
+ "Interrupt THREAD and make it run FUNCTION."
+ (let ((function (coerce function 'function)))
+ (sb!sys:with-pinned-objects (function)
+ (sb!unix::syscall* ("interrupt_thread"
+ sb!alien:unsigned-long sb!alien:unsigned-long)
+ thread
+ thread
+ (sb!kernel:get-lisp-obj-address function)))))
+
+(defun terminate-thread (thread-id)
+ "Terminate the thread identified by THREAD-ID, by causing it to run
+SB-EXT:QUIT - the usual cleanup forms will be evaluated"
+ (interrupt-thread thread-id 'sb!ext:quit))
+
+(declaim (inline current-thread-id))
+(defun current-thread-id ()
+ (logand
+ (sb!sys:sap-int
+ (sb!vm::current-thread-offset-sap sb!vm::thread-pid-slot))
+ ;; KLUDGE pids are 16 bit really. Avoid boxing the return value
+ (1- (ash 1 16))))
+
+;;;; iterate over the in-memory threads
+
+(defun mapcar-threads (function)
+ "Call FUNCTION once for each known thread, giving it the thread structure as argument"
+ (let ((function (coerce function 'function)))
+ (loop for thread = (alien-sap (extern-alien "all_threads" (* t)))
+ then (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot))
+ until (sb!sys:sap= thread (sb!sys:int-sap 0))
+ collect (funcall function thread))))
+
;;;; job control, independent listeners
(defstruct session
(defun init-job-control ()
(setf *session* (new-session)))
+(defun %delete-thread-from-session (tid)
+ (with-mutex ((session-lock *session*))
+ (setf (session-threads *session*)
+ (delete tid (session-threads *session*))
+ (session-interactive-threads *session*)
+ (delete tid (session-interactive-threads *session*)))))
+
(defun call-with-new-session (fn)
- (let ((tid (current-thread-id)))
- (with-mutex ((session-lock *session*))
- (setf (session-threads *session*)
- (delete tid (session-threads *session*))
- (session-interactive-threads *session*)
- (delete tid (session-interactive-threads *session*))))
- (let ((*session* (new-session)))
- (funcall fn))))
+ (%delete-thread-from-session (current-thread-id))
+ (let ((*session* (new-session))) (funcall fn)))
(defmacro with-new-session (args &body forms)
(declare (ignore args)) ;for extensibility
`(labels ((,fb-name () ,@forms))
(call-with-new-session (function ,fb-name)))))
+;;; this is called from a C signal handler: some signals may be masked
+(defun handle-thread-exit (tid)
+ "Remove thread id TID from the session, if it's there"
+ (%delete-thread-from-session tid))
+
(defun terminate-session ()
"Kill all threads in session exept for this one. Does nothing if current
thread is not the foreground thread"
(defun debugger-wait-until-foreground-thread (stream)
"Returns T if thread had been running in background, NIL if it was
interactive."
+ (declare (ignore stream))
(prog1
(with-mutex ((session-lock *session*))
(not (member (current-thread-id)
(session-interactive-threads *session*))))
(get-foreground)))
-(defun thread-repl-prompt-fun (out-stream)
- (get-foreground)
- (let ((stopped-threads (cdr (session-interactive-threads *session*))))
- (when stopped-threads
- (format out-stream "~{~&Thread ~A suspended~}~%" stopped-threads))
- (sb!impl::repl-prompt-fun out-stream)))
(defun get-foreground ()
- (loop
- (with-mutex ((session-lock *session*))
- (let ((tid (current-thread-id)))
- (when (eql (car (session-interactive-threads *session*)) tid)
- (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler)
- (return-from get-foreground t))
- (unless (member tid *interactive-threads*)
- (setf (cdr (last (session-interactive-threads *session*)))
- (list tid)))
- (condition-wait
- (session-interactive-threads-queue *session*)
- (session-lock *session*))))))
+ (let ((was-foreground t))
+ (loop
+ (with-mutex ((session-lock *session*))
+ (let ((tid (current-thread-id))
+ (int-t (session-interactive-threads *session*)))
+ (when (eql (car int-t) tid)
+ (unless was-foreground
+ (format *query-io* "Resuming thread ~A~%" tid))
+ (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler)
+ (return-from get-foreground t))
+ (setf was-foreground nil)
+ (unless (member tid int-t)
+ (setf (cdr (last int-t))
+ (list tid)))
+ (condition-wait
+ (session-interactive-threads-queue *session*)
+ (session-lock *session*)))))))
(defun release-foreground (&optional next)
"Background this thread. If NEXT is supplied, arrange for it to have the foreground next"
(with-mutex ((session-lock *session*))
(let ((tid (current-thread-id)))
(setf (session-interactive-threads *session*)
- (delete tid *interactive-threads*))
+ (delete tid (session-interactive-threads *session*)))
(sb!sys:enable-interrupt sb!unix:sigint :ignore)
(when next
(setf (session-interactive-threads *session*)
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