1.0.19.7: refactor stack allocation decisions
[sbcl.git] / src / code / target-thread.lisp
index ec94be8..c37afef 100644 (file)
@@ -39,14 +39,22 @@ in future versions."
       "The name of the thread. Setfable.")
 
 (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)
+  (print-unreadable-object (thread stream :type t :identity t)
+    (let* ((cookie (list thread))
+           (info (if (thread-alive-p thread)
+                     :running
+                     (multiple-value-list (join-thread thread :default cookie))))
+           (state (if (eq :running info)
+                      info
+                      (if (eq cookie (car info))
+                          :aborted
+                          :finished)))
+           (values (when (eq :finished state) info)))
+      (format stream "~@[~S ~]~:[~A~;~A~:[ no values~; values: ~:*~{~S~^, ~}~]~]"
+              (thread-name thread)
+              (eq :finished state)
+              state
+              values))))
 
 (defun thread-alive-p (thread)
   #!+sb-doc
@@ -59,8 +67,11 @@ in future versions."
 (defvar *all-threads* ())
 (defvar *all-threads-lock* (make-mutex :name "all threads lock"))
 
+(defvar *default-alloc-signal* nil)
+
 (defmacro with-all-threads-lock (&body body)
-  `(call-with-system-mutex (lambda () ,@body) *all-threads-lock*))
+  `(with-system-mutex (*all-threads-lock*)
+     ,@body))
 
 (defun list-all-threads ()
   #!+sb-doc
@@ -72,8 +83,8 @@ in future versions."
 (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 ()
+(declaim (inline current-thread-os-thread))
+(defun current-thread-os-thread ()
   (sap-int
    (sb!vm::current-thread-offset-sap sb!vm::thread-os-thread-slot)))
 
@@ -81,7 +92,7 @@ in future versions."
   (/show0 "Entering INIT-INITIAL-THREAD")
   (let ((initial-thread (%make-thread :name "initial thread"
                                       :%alive-p t
-                                      :os-thread (current-thread-sap-id))))
+                                      :os-thread (current-thread-os-thread))))
     (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
@@ -250,7 +261,8 @@ ALLOW-WITH-INTERRUPTS allows the call to be interrupted from sleep.
 
 It is recommended that you use WITH-MUTEX instead of calling GET-MUTEX
 directly."
-  (declare (type mutex mutex) (optimize (speed 3)))
+  (declare (type mutex mutex) (optimize (speed 3))
+           #!-sb-thread (ignore waitp))
   (unless new-owner
     (setq new-owner *current-thread*))
   (when (eql new-owner (mutex-%owner mutex))
@@ -499,11 +511,21 @@ on this semaphore, then N of them is woken up."
 
 (defvar *session* nil)
 
-;;; the debugger itself tries to acquire the session lock, don't let
+;;; The debugger itself tries to acquire the session lock, don't let
 ;;; funny situations (like getting a sigint while holding the session
-;;; lock) occur
+;;; lock) occur. At the same time we need to allow interrupts while
+;;; *waiting* for the session lock for things like GET-FOREGROUND
+;;; to be interruptible.
+;;;
+;;; Take care: we sometimes need to obtain the session lock while holding
+;;; on to *ALL-THREADS-LOCK*, so we must _never_ obtain it _after_ getting
+;;; a session lock! (Deadlock risk.)
+;;;
+;;; FIXME: It would be good to have ordered locks to ensure invariants like
+;;; the above.
 (defmacro with-session-lock ((session) &body body)
-  `(call-with-system-mutex (lambda () ,@body) (session-lock ,session)))
+  `(with-system-mutex ((session-lock ,session) :allow-with-interrupts t)
+     ,@body))
 
 (defun new-session ()
   (make-session :threads (list *current-thread*)
@@ -678,19 +700,23 @@ around and can be retrieved by JOIN-THREAD."
             ;; of Allegro's *cl-default-special-bindings*, as that is at
             ;; least accessible to users to secure their own libraries.
             ;;   --njf, 2006-07-15
-            (let ((*current-thread* thread)
-                  (*restart-clusters* nil)
-                  (*handler-clusters* nil)
-                  (*condition-restarts* nil)
-                  (sb!impl::*step-out* nil)
-                  ;; internal printer variables
-                  (sb!impl::*previous-case* nil)
-                  (sb!impl::*previous-readtable-case* nil)
-                  (sb!impl::*merge-sort-temp-vector* (vector)) ; keep these small!
-                  (sb!impl::*zap-array-data-temp* (vector))    ;
-                  (sb!impl::*internal-symbol-output-fun* nil)
-                  (sb!impl::*descriptor-handlers* nil)) ; serve-event
-              (setf (thread-os-thread thread) (current-thread-sap-id))
+            (let* ((*current-thread* thread)
+                   (*restart-clusters* nil)
+                   (*handler-clusters* (sb!kernel::initial-handler-clusters))
+                   (*condition-restarts* nil)
+                   (sb!impl::*deadline* nil)
+                   (sb!impl::*step-out* nil)
+                   ;; internal printer variables
+                   (sb!impl::*previous-case* nil)
+                   (sb!impl::*previous-readtable-case* nil)
+                   (empty (vector))
+                   (sb!impl::*merge-sort-temp-vector* empty)
+                   (sb!impl::*zap-array-data-temp* empty)
+                   (sb!impl::*internal-symbol-output-fun* nil)
+                   (sb!impl::*descriptor-handlers* nil)) ; serve-event
+              ;; Binding from C
+              (setf sb!vm:*alloc-signal* *default-alloc-signal*)
+              (setf (thread-os-thread thread) (current-thread-os-thread))
               (with-mutex ((thread-result-lock thread))
                 (with-all-threads-lock
                   (push thread *all-threads*))
@@ -775,7 +801,8 @@ return DEFAULT if given or else signal JOIN-THREAD-ERROR."
       "The thread that was not interrupted.")
 
 (defmacro with-interruptions-lock ((thread) &body body)
-  `(call-with-system-mutex (lambda () ,@body) (thread-interruptions-lock ,thread)))
+  `(with-system-mutex ((thread-interruptions-lock ,thread))
+     ,@body))
 
 ;; Called from the signal handler in C.
 (defun run-interruption ()
@@ -825,31 +852,61 @@ won't like the effect."
 SB-EXT:QUIT - the usual cleanup forms will be evaluated"
   (interrupt-thread thread 'sb!ext:quit))
 
-;;; internal use only.  If you think you need to use this, either you
+(define-alien-routine "thread_yield" int)
+
+#!+sb-doc
+(setf (fdocumentation 'thread-yield 'function)
+      "Yield the processor to other threads.")
+
+;;; internal use only.  If you think you need to use these, either you
 ;;; are an SBCL developer, are doing something that you should discuss
 ;;; with an SBCL developer first, or are doing something that you
 ;;; should probably discuss with a professional psychiatrist first
 #!+sb-thread
-(defun thread-sap-for-id (id)
-  (let ((thread-sap (alien-sap (extern-alien "all_threads" (* t)))))
-    (loop
-     (when (sap= thread-sap (int-sap 0)) (return nil))
-     (let ((os-thread (sap-ref-word thread-sap
-                                    (* sb!vm:n-word-bytes
-                                       sb!vm::thread-os-thread-slot))))
-       (when (= os-thread id) (return thread-sap))
-       (setf thread-sap
-             (sap-ref-sap thread-sap (* sb!vm:n-word-bytes
-                                        sb!vm::thread-next-slot)))))))
-
-#!+sb-thread
-(defun symbol-value-in-thread (symbol thread-sap)
-  (let* ((index (sb!vm::symbol-tls-index symbol))
-         (tl-val (sap-ref-word thread-sap
-                               (* sb!vm:n-word-bytes index))))
-    (if (eql tl-val sb!vm::no-tls-value-marker-widetag)
-        (sb!vm::symbol-global-value symbol)
-        (make-lisp-obj tl-val))))
+(progn
+  (defun %thread-sap (thread)
+    (let ((thread-sap (alien-sap (extern-alien "all_threads" (* t))))
+          (target (thread-os-thread thread)))
+      (loop
+        (when (sap= thread-sap (int-sap 0)) (return nil))
+        (let ((os-thread (sap-ref-word thread-sap
+                                       (* sb!vm:n-word-bytes
+                                          sb!vm::thread-os-thread-slot))))
+          (when (= os-thread target) (return thread-sap))
+          (setf thread-sap
+                (sap-ref-sap thread-sap (* sb!vm:n-word-bytes
+                                           sb!vm::thread-next-slot)))))))
+
+  (defun %symbol-value-in-thread (symbol thread)
+    (tagbody
+       ;; Prevent the dead from dying completely while we look for the TLS area...
+       (with-all-threads-lock
+         (if (thread-alive-p thread)
+             (let* ((offset (* sb!vm:n-word-bytes (sb!vm::symbol-tls-index symbol)))
+                    (tl-val (sap-ref-word (%thread-sap thread) offset)))
+               (if (eql tl-val sb!vm::no-tls-value-marker-widetag)
+                   (go :unbound)
+                   (return-from %symbol-value-in-thread (values (make-lisp-obj tl-val) t))))
+             (return-from %symbol-value-in-thread (values nil nil))))
+     :unbound
+       (error "Cannot read thread-local symbol value: ~S unbound in ~S" symbol thread)))
+
+  (defun %set-symbol-value-in-thread (symbol thread value)
+    (tagbody
+       (with-pinned-objects (value)
+         ;; Prevent the dead from dying completely while we look for the TLS area...
+         (with-all-threads-lock
+           (if (thread-alive-p thread)
+               (let* ((offset (* sb!vm:n-word-bytes (sb!vm::symbol-tls-index symbol)))
+                      (sap (%thread-sap thread))
+                      (tl-val (sap-ref-word sap offset)))
+                 (if (eql tl-val sb!vm::no-tls-value-marker-widetag)
+                     (go :unbound)
+                     (setf (sap-ref-word sap offset) (get-lisp-obj-address value)))
+                 (return-from %set-symbol-value-in-thread (values value t)))
+               (return-from %set-symbol-value-in-thread (values nil nil)))))
+     :unbound
+       (error "Cannot set thread-local symbol value: ~S unbound in ~S" symbol thread))))
 
 (defun sb!vm::locked-symbol-global-value-add (symbol-name delta)
   (sb!vm::locked-symbol-global-value-add symbol-name delta))