X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Ftarget-thread.lisp;h=dd25ecbbce9595f49501c954a98ded9342935dfe;hb=9f409e8f8b0a0530725a13805f2b1b3c121ad46a;hp=d55ff8f6a0ed15a7310b182441a958650e3d2828;hpb=2378b4fe567a8fea78b1e4915b9497d8c18ca92f;p=sbcl.git

diff --git a/src/code/target-thread.lisp b/src/code/target-thread.lisp
index d55ff8f..dd25ecb 100644
--- a/src/code/target-thread.lisp
+++ b/src/code/target-thread.lisp
@@ -1,396 +1,81 @@
-(in-package "SB!THREAD")
-
-(sb!alien::define-alien-routine ("create_thread" %create-thread)
-     sb!alien:unsigned-long
-  (lisp-fun-address sb!alien:unsigned-long))
-
-(defun make-thread (function)
-  (let ((real-function (coerce function 'function)))
-    (%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 :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))))))))
-
-;;; Conventional wisdom says that it's a bad idea to use these unless
-;;; you really need to.  Use a lock or a waitqueue instead
-(defun suspend-thread (thread-id)
-  (sb!unix:unix-kill thread-id :sigstop))
-(defun resume-thread (thread-id)
-  (sb!unix:unix-kill thread-id :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 :sigterm)
-  ;; may have been stopped for some reason, so now wake it up to
-  ;; deliver the TERM
-  (sb!unix:unix-kill thread-id :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))
+;;;; 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.
 
+(in-package "SB!THREAD")
 
-(defun current-thread-id ()
+(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-pid-slot)))
-
-;;;; 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
-(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)))
-
-(defmacro with-spinlock ((queue) &body body)
-  (with-unique-names (pid)
-    `(unwind-protect
-      (let ((,pid (current-thread-id)))
-	(get-spinlock ,queue 2 ,pid)
-	,@body)
-      (setf (waitqueue-lock ,queue) 0))))
-
-;;;; the higher-level locking operations are based on waitqueues
-
-(defstruct waitqueue
-  (name nil :type (or null simple-base-string))
-  (lock 0)
-  (data nil))
-
-(defstruct (mutex (:include waitqueue))
-  (value nil))
-
-(sb!alien:define-alien-routine "block_sigcont"  void)
-(sb!alien:define-alien-routine "unblock_sigcont_and_sleep"  void)
-
-;;; 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)))
-    ;; 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))
-    (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))))))
-
-;;; this should only be called while holding the queue spinlock.
-(defun signal-queue-head (queue)
-  (let ((p (car (waitqueue-data queue))))
-    (when p (sb!unix:unix-kill p  :sigcont))))
-
-;;;; mutex
-
-(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))))
-    (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))))
-
-(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)))
-
-
-(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))))
-
-(defun condition-notify (queue)
-  "Notify one of the processes waiting on QUEUE"
-  (with-spinlock (queue) (signal-queue-head queue)))
-
-
-;;;; multiple independent listeners
-
-(defvar *session-lock* nil)
-
-(defun make-listener-thread (tty-name)  
-  (assert (probe-file tty-name))
-  ;; FIXME probably still need to do some tty stuff to get signals
-  ;; delivered correctly.
-  ;; FIXME 
-  (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* ((*session-lock*
-		       (make-mutex :name (format nil "lock for ~A" tty-name)))
-		      (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))
-		 (get-mutex *session-lock*)
-		 (sb!sys:enable-interrupt :sigint #'sb!unix::sigint-handler)
-		 (unwind-protect
-		      (sb!impl::toplevel-repl nil)
-		   (sb!int:flush-standard-output-streams)))))
-      (make-thread #'thread-repl))))
-  
-;;;; job control
-
-(defvar *background-threads-wait-for-debugger* t)
-;;; may be T, NIL, or a function called with a stream and thread id 
-;;; as its two arguments, returning NIl or T
-
-;;; 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
-already the foreground thread, or transfers control to the first applicable
-restart if *BACKGROUND-THREADS-WAIT-FOR-DEBUGGER* says to do that instead"
-  (let* ((wait-p *background-threads-wait-for-debugger*)
-	 (*background-threads-wait-for-debugger* nil)
-	 (lock *session-lock*))
-    (when (not (eql (mutex-value lock)   (CURRENT-THREAD-ID)))
-      (when (functionp wait-p) 
-	(setf wait-p 
-	      (funcall wait-p stream (CURRENT-THREAD-ID))))
-      (cond (wait-p (get-foreground))
-	    (t  (invoke-restart (car (compute-restarts))))))))
-
-;;; install this with
-;;; (setf SB-INT:*REPL-PROMPT-FUN* #'sb-thread::thread-repl-prompt-fun)
-;;; One day it will be default
-(defun thread-repl-prompt-fun (out-stream)
-  (let ((lock *session-lock*))
-    (get-foreground)
-    (let ((stopped-threads (waitqueue-data lock)))
-      (when stopped-threads
-	(format out-stream "~{~&Thread ~A suspended~}~%" stopped-threads))
-      (sb!impl::repl-prompt-fun out-stream))))
-
-(defun resume-stopped-thread (id)
-  (let ((pid (current-thread-id))
-	(lock *session-lock*)) 
-    (with-spinlock (lock)
-      (setf (waitqueue-data lock)
-	    (cons id (delete id  (waitqueue-data lock)))))
-    (release-foreground)))
-
-(defstruct rwlock
-  (name nil :type (or null simple-base-string))
-  (value 0 :type fixnum)
-  (max-readers nil :type (or fixnum null))
-  (max-writers 1 :type fixnum))
-#+nil
-(macrolet
-    ((make-rwlocking-function (lock-fn unlock-fn increment limit test)
-       (let ((do-update '(when (eql old-value
-				(sb!vm::%instance-set-conditional
-				 lock 2 old-value new-value))
-			  (return (values t old-value))))
-	     (vars `((timeout (and timeout (+ (get-internal-real-time) timeout)))
-		     old-value
-		     new-value
-		     (limit ,limit))))
-	 (labels ((do-setfs (v) `(setf old-value (rwlock-value lock)
-				  new-value (,v old-value ,increment))))
-	   `(progn
-	     (defun ,lock-fn (lock timeout)
-	       (declare (type rwlock lock))
-	       (let ,vars
-		 (loop
-		  ,(do-setfs '+)
-		  (when ,test
-		    ,do-update)
-		  (when (sleep-a-bit timeout) (return nil)) ;expired
-		  )))
-	     ;; unlock doesn't need timeout or test-in-range
-	     (defun ,unlock-fn (lock)
-	       (declare (type rwlock lock))
-	       (declare (ignorable limit))
-	       (let ,(cdr vars)
-		 (loop
-		  ,(do-setfs '-)
-		  ,do-update))))))))
-    
-  (make-rwlocking-function %lock-for-reading %unlock-for-reading 1
-			   (rwlock-max-readers lock)
-			   (and (>= old-value 0)
-				(or (null limit) (<= new-value limit))))
-  (make-rwlocking-function %lock-for-writing %unlock-for-writing -1
-			   (- (rwlock-max-writers lock))
-			   (and (<= old-value 0)
-				(>= new-value limit))))
-#+nil  
-(defun get-rwlock (lock direction &optional timeout)
-  (ecase direction
-    (:read (%lock-for-reading lock timeout))
-    (:write (%lock-for-writing lock timeout))))
-#+nil
-(defun free-rwlock (lock direction)
-  (ecase direction
-    (:read (%unlock-for-reading lock))
-    (:write (%unlock-for-writing lock))))
-
-;;;; beyond this point all is commented.
-
-;;; Lock-Wait-With-Timeout  --  Internal
-;;;
-;;; Wait with a timeout for the lock to be free and acquire it for the
-;;; *current-process*.
-;;;
-#+nil
-(defun lock-wait-with-timeout (lock whostate timeout)
-  (declare (type lock lock))
-  (process-wait-with-timeout
-   whostate timeout
-   #'(lambda ()
-       (declare (optimize (speed 3)))
-       #-i486
-       (unless (lock-process lock)
-	 (setf (lock-process lock) *current-process*))
-       #+i486
-       (null (kernel:%instance-set-conditional
-	      lock 2 nil *current-process*)))))
-
-;;; With-Lock-Held  --  Public
-;;;
-#+nil
-(defmacro with-lock-held ((lock &optional (whostate "Lock Wait")
-				&key (wait t) timeout)
-			  &body body)
-  "Execute the body with the lock held. If the lock is held by another
-  process then the current process waits until the lock is released or
-  an optional timeout is reached. The optional wait timeout is a time in
-  seconds acceptable to process-wait-with-timeout.  The results of the
-  body are return upon success and NIL is return if the timeout is
-  reached. When the wait key is NIL and the lock is held by another
-  process then NIL is return immediately without processing the body."
-  (let ((have-lock (gensym)))
-    `(let ((,have-lock (eq (lock-process ,lock) *current-process*)))
-      (unwind-protect
-	   ,(cond ((and timeout wait)
-		   `(progn
-		      (when (and (error-check-lock-p ,lock) ,have-lock)
-			(error "Dead lock"))
-		      (when (or ,have-lock
-				 #+i486 (null (kernel:%instance-set-conditional
-					       ,lock 2 nil *current-process*))
-				 #-i486 (seize-lock ,lock)
-				 (if ,timeout
-				     (lock-wait-with-timeout
-				      ,lock ,whostate ,timeout)
-				     (lock-wait ,lock ,whostate)))
-			,@body)))
-		  (wait
-		   `(progn
-		      (when (and (error-check-lock-p ,lock) ,have-lock)
-		        (error "Dead lock"))
-		      (unless (or ,have-lock
-				 #+i486 (null (kernel:%instance-set-conditional
-					       ,lock 2 nil *current-process*))
-				 #-i486 (seize-lock ,lock))
-			(lock-wait ,lock ,whostate))
-		      ,@body))
-		  (t
-		   `(when (or (and (recursive-lock-p ,lock) ,have-lock)
-			      #+i486 (null (kernel:%instance-set-conditional
-					    ,lock 2 nil *current-process*))
-			      #-i486 (seize-lock ,lock))
-		      ,@body)))
-	(unless ,have-lock
-	  #+i486 (kernel:%instance-set-conditional
-		  ,lock 2 *current-process* nil)
-	  #-i486 (when (eq (lock-process ,lock) *current-process*)
-		   (setf (lock-process ,lock) nil)))))))
-
-
-
+   (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))))