X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=dd25ecbbce9595f49501c954a98ded9342935dfe;hb=9f409e8f8b0a0530725a13805f2b1b3c121ad46a;hp=59e96adaa0e1c3833dccb9f00bf9a4511357f0b5;hpb=9c0fdf35270405ee8384d7f6a5a4b641d5df33c4;p=sbcl.git

diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp
index 59e96ad..dd25ecb 100644
--- a/src/code/target-thread.lisp
+++ b/src/code/target-thread.lisp
@@ -1,438 +1,81 @@
-(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))
-
-(sb!alien::define-alien-routine "signal_thread_to_dequeue"
-    sb!alien:unsigned-int
-  (thread-pid sb!alien: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
-(declaim (inline get-spinlock release-spinlock))
-
-(defun get-spinlock (lock offset new-value)
-  (declare (optimize (speed 3) (safety 0)))
-  (loop until
-	(eql (sb!vm::%instance-set-conditional lock offset 0 new-value) 0)))
-
-;; this should do nothing if we didn't own the lock, so safe to use in
-;; unwind-protect cleanups when lock acquisition failed for some reason
-(defun release-spinlock (lock offset our-value)
-  (declare (optimize (speed 3) (safety 0)))
-  (sb!vm::%instance-set-conditional lock offset our-value 0))
-
-(defmacro with-spinlock ((queue) &body body)
-  (with-unique-names (pid)
-    `(let ((,pid (current-thread-id)))
-       (unwind-protect
-	    (progn
-	      (get-spinlock ,queue 2 ,pid)
-	      ,@body)
-	 (release-spinlock ,queue 2 ,pid)))))
-
-
-;;;; the higher-level locking operations are based on waitqueues
-
-(declaim (inline waitqueue-data-address mutex-value-address))
-
-(defstruct waitqueue
-  (name nil :type (or null simple-base-string))
-  (lock 0)
-  (data nil))
-
-;;; The bare 4 here and 5 below are offsets of the slots in the struct.
-;;; There ought to be some better way to get these numbers
-(defun waitqueue-data-address (lock)
-  (declare (optimize (speed 3)))
-  (sb!ext:truly-the
-   (unsigned-byte 32)
-   (+ (sb!kernel:get-lisp-obj-address lock)
-      (- (* 4 sb!vm:n-word-bytes) sb!vm:instance-pointer-lowtag))))
-
-(defstruct (mutex (:include waitqueue))
-  (value nil))
-
-(defun mutex-value-address (lock)
-  (declare (optimize (speed 3)))
-  (sb!ext:truly-the
-   (unsigned-byte 32)
-   (+ (sb!kernel:get-lisp-obj-address lock)
-      (- (* 5 sb!vm:n-word-bytes) sb!vm:instance-pointer-lowtag))))
-
-(sb!alien:define-alien-routine "block_sigcont"  void)
-(sb!alien:define-alien-routine "unblock_sigcont_and_sleep"  void)
-
-#!+sb-futex
-(declaim (inline futex-wait futex-wake))
-#!+sb-futex
-(sb!alien:define-alien-routine
-    "futex_wait" int (word unsigned-long) (old-value unsigned-long))
-#!+sb-futex
-(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)
-  (let ((pid (current-thread-id)))
-    (block-sigcont)
-    (when lock (release-mutex lock))
-    (sb!sys:without-interrupts
-     (pushnew pid (waitqueue-data queue)))
-    (setf (waitqueue-lock queue) 0)
-    (unblock-sigcont-and-sleep)))
-
-;;; this should only be called while holding the queue spinlock.  It doesn't
-;;; release it
-(defun dequeue (queue)
-  (let ((pid (current-thread-id)))
-    (sb!sys:without-interrupts     
-     (setf (waitqueue-data queue)
-	   (delete pid (waitqueue-data queue))))))
+;;;; support for threads in the target machine common to uni- and
+;;;; multithread systems
+
+;;;; 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.
 
-;;; this should only be called while holding the queue spinlock.
-(defun signal-queue-head (queue)
-  (let ((p (car (waitqueue-data queue))))
-    (when p (signal-thread-to-dequeue p))))
-
-;;;; mutex
-
-;;; i suspect there may be a race still in this: the futex version requires
-;;; the old mutex value before sleeping, so how do we get away without it
-(defun get-mutex (lock &optional new-value (wait-p t))
-  (declare (type mutex lock) (optimize (speed 3)))
-  (let ((pid (current-thread-id)))
-    (unless new-value (setf new-value pid))
-    (assert (not (eql new-value (mutex-value lock))))
-    (get-spinlock lock 2 pid)
-    (loop
-     (unless
-	 ;; args are object slot-num old-value new-value
-	 (sb!vm::%instance-set-conditional lock 4 nil new-value)
-       (dequeue lock)
-       (setf (waitqueue-lock lock) 0)
-       (return t))
-     (unless wait-p
-       (setf (waitqueue-lock lock) 0)
-       (return nil))
-     (wait-on-queue lock nil))))
-
-#!+sb-futex
-(defun get-mutex/futex (lock &optional new-value (wait-p t))
-  (declare (type mutex lock)  (optimize (speed 3)))
-  (let ((pid (current-thread-id))
-	old)
-    (unless new-value (setf new-value pid))
-    (assert (not (eql new-value (mutex-value lock))))
-    (loop
-     (unless
-	 (setf old (sb!vm::%instance-set-conditional lock 4 nil new-value))
-       (return t))
-     (unless wait-p (return nil))
-     (futex-wait (mutex-value-address lock)
-		 (sb!kernel:get-lisp-obj-address old)))))
-
-(defun release-mutex (lock &optional (new-value nil))
-  (declare (type mutex lock))
-  ;; we assume the lock is ours to release
-  (with-spinlock (lock)
-    (setf (mutex-value lock) new-value)
-    (signal-queue-head lock)))
-
-#!+sb-futex
-(defun release-mutex/futex (lock)
-  (declare (type mutex 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)
-  "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."
-  (assert lock)
-  (let ((value (mutex-value lock)))
-    (unwind-protect
-	 (progn
-	   (get-spinlock queue 2 (current-thread-id))
-	   (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.
-      (with-spinlock (queue)
-	(dequeue queue))
-      (get-mutex lock value))))
-
-#!+sb-futex
-(defun condition-wait/futex (queue lock)
-  (assert lock)
-  (let ((value (mutex-value lock)))
-    (unwind-protect
-	 (let ((me (current-thread-id)))
-	   ;; XXX we should do something to ensure that the result of this setf
-	   ;; is visible to all CPUs
-	   (setf (waitqueue-data queue) me)
-	   (release-mutex lock)
-	   ;; Now we go to sleep using futex-wait.  If anyone else
-	   ;; manages to grab LOCK and call CONDITION-NOTIFY during
-	   ;; this comment, it will change queue->data, and so
-	   ;; futex-wait returns immediately instead of sleeping.
-	   ;; Ergo, no lost wakeup
-	   (futex-wait (waitqueue-data-address queue)
-		       (sb!kernel:get-lisp-obj-address me)))
-      ;; 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.
-      (get-mutex lock value))))
-
-
-(defun condition-notify (queue)
-  "Notify one of the processes waiting on QUEUE"
-  (with-spinlock (queue) (signal-queue-head queue)))
-
-#!+sb-futex
-(defun condition-notify/futex (queue)
-  "Notify one of the processes waiting on QUEUE."
-  (let ((me (current-thread-id)))
-    ;; no problem if >1 thread notifies during the comment in
-    ;; condition-wait: as long as the value in queue-data isn't the
-    ;; waiting thread's id, it matters not what it is
-    ;; XXX we should do something to ensure that the result of this setf
-    ;; is visible to all CPUs
-    (setf (waitqueue-data queue) me)
-    (futex-wake (waitqueue-data-address queue) 1)))
-
-#!+sb-futex
-(defun condition-broadcast/futex (queue)
-  (let ((me (current-thread-id)))
-    (setf (waitqueue-data queue) me)
-    (futex-wake (waitqueue-data-address queue) (ash 1 30))))
-
-(defun condition-broadcast (queue)
-  "Notify all of the processes waiting on QUEUE."
-  (with-spinlock (queue)
-    (map nil #'signal-thread-to-dequeue (waitqueue-data queue))))
-
-;;; Futexes may be available at compile time but not runtime, so we
-;;; default to not using them unless os_init says they're available
-(defun maybe-install-futex-functions ()
-  #!+sb-futex
-  (unless (zerop (extern-alien "linux_supports_futex" int))
-    (setf (fdefinition 'get-mutex) #'get-mutex/futex
-	  (fdefinition 'release-mutex) #'release-mutex/futex
-	  (fdefinition 'condition-wait) #'condition-wait/futex
-	  (fdefinition 'condition-broadcast) #'condition-broadcast/futex
-	  (fdefinition 'condition-notify) #'condition-notify/futex)
-    t))
-
-;;;; job control, independent listeners
-
-(defstruct session 
-  (lock (make-mutex))
-  (threads nil)
-  (interactive-threads nil)
-  (interactive-threads-queue (make-waitqueue)))
-
-(defun new-session ()
-  (let ((tid (current-thread-id)))
-    (make-session :threads (list tid)
-		  :interactive-threads (list tid))))
-
-(defun init-job-control ()
-  (setf *session* (new-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))))
-
-(defmacro with-new-session (args &body forms)
-  (declare (ignore args))		;for extensibility
-  (sb!int:with-unique-names (fb-name)
-    `(labels ((,fb-name () ,@forms))
-      (call-with-new-session (function ,fb-name)))))
-
-(defun terminate-session ()
-  "Kill all threads in session exept for this one.  Does nothing if current
-thread is not the foreground thread"
-  (let* ((tid (current-thread-id))
-	 (to-kill
-	  (with-mutex ((session-lock *session*))
-	    (and (eql tid (car (session-interactive-threads *session*)))
-		 (session-threads *session*)))))
-    ;; do the kill after dropping the mutex; unwind forms in dying
-    ;; threads may want to do session things
-    (dolist (p to-kill)
-      (unless (eql p tid) (terminate-thread p)))))
-
-;;; called from top of invoke-debugger
-(defun debugger-wait-until-foreground-thread (stream)
-  "Returns T if thread had been running in background, NIL if it was
-interactive."
-  (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*))))))
-
-(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*))
-      (sb!sys:enable-interrupt sb!unix:sigint :ignore)
-      (when next 
-	(setf (session-interactive-threads *session*)
-	      (list* next 
-		     (delete next (session-interactive-threads *session*)))))
-      (condition-broadcast (session-interactive-threads-queue *session*)))))
+(in-package "SB!THREAD")
 
-(defun make-listener-thread (tty-name)  
-  (assert (probe-file tty-name))
-  (let* ((in (sb!unix:unix-open (namestring tty-name) sb!unix:o_rdwr #o666))
-	 (out (sb!unix:unix-dup in))
-	 (err (sb!unix:unix-dup in)))
-    (labels ((thread-repl () 
-	       (sb!unix::unix-setsid)
-	       (let* ((sb!impl::*stdin* 
-		       (sb!sys:make-fd-stream in :input t :buffering :line))
-		      (sb!impl::*stdout* 
-		       (sb!sys:make-fd-stream out :output t :buffering :line))
-		      (sb!impl::*stderr* 
-		       (sb!sys:make-fd-stream err :output t :buffering :line))
-		      (sb!impl::*tty* 
-		       (sb!sys:make-fd-stream err :input t :output t :buffering :line))
-		      (sb!impl::*descriptor-handlers* nil))
-		 (with-new-session ()
-		   (sb!sys:enable-interrupt sb!unix:sigint #'sb!unix::sigint-handler)
-		   (unwind-protect
-			(sb!impl::toplevel-repl nil)
-		     (sb!int:flush-standard-output-streams))))))
-      (make-thread #'thread-repl))))
+(defstruct (thread (:constructor %make-thread))
+  name
+  %sap)
+
+(def!method print-object ((thread thread) stream)
+  (if (thread-name thread)
+      (print-unreadable-object (thread stream :type t :identity t)
+        (prin1 (thread-name thread) stream))
+      (print-unreadable-object (thread stream :type t :identity t)
+        ;; body is empty => there is only one space between type and
+        ;; identity
+        ))
+  thread)
+
+(defun thread-state (thread)
+  (let ((state
+	 (sb!sys:sap-int
+	  (sb!sys:sap-ref-sap (thread-%sap thread)
+			      (* sb!vm::thread-state-slot
+				 sb!vm::n-word-bytes)))))
+    (ecase state
+      (#.(sb!vm:fixnumize 0) :starting)
+      (#.(sb!vm:fixnumize 1) :running)
+      (#.(sb!vm:fixnumize 2) :suspended)
+      (#.(sb!vm:fixnumize 3) :dead))))
+
+(defun %set-thread-state (thread state)
+  (setf (sb!sys:sap-ref-sap (thread-%sap thread)
+                            (* sb!vm::thread-state-slot
+                               sb!vm::n-word-bytes))
+        (sb!sys:int-sap
+	  (ecase state
+	    (:starting #.(sb!vm:fixnumize 0))
+	    (:running #.(sb!vm:fixnumize 1))
+	    (:suspended #.(sb!vm:fixnumize 2))
+	    (:dead #.(sb!vm:fixnumize 3))))))
+
+(defun thread-alive-p (thread)
+  (not (eq :dead (thread-state thread))))
+
+;; A thread is eligible for gc iff it has finished and there are no
+;; more references to it. This list is supposed to keep a reference to
+;; all running threads.
+(defvar *all-threads* ())
+(defvar *all-threads-lock* (make-mutex :name "all threads lock"))
+
+(defun list-all-threads ()
+  (with-mutex (*all-threads-lock*)
+    (copy-list *all-threads*)))
+
+(declaim (inline current-thread-sap))
+(defun current-thread-sap ()
+  (sb!vm::current-thread-offset-sap sb!vm::thread-this-slot))
+
+(declaim (inline current-thread-sap-id))
+(defun current-thread-sap-id ()
+  (sb!sys:sap-int
+   (sb!vm::current-thread-offset-sap sb!vm::thread-os-thread-slot)))
+
+(defun init-initial-thread ()
+  (let ((initial-thread (%make-thread :name "initial thread"
+                                      :%sap (current-thread-sap))))
+    (setq *current-thread* initial-thread)
+    ;; Either *all-threads* is empty or it contains exactly one thread
+    ;; in case we are in reinit since saving core with multiple
+    ;; threads doesn't work.
+    (setq *all-threads* (list initial-thread))))