unsigned-int
(thread-id unsigned-long))
+(define-alien-routine reap-dead-threads void)
+
(defvar *session* nil)
;;;; queues, locks
;;; 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))
+ "Acquire LOCK, setting it to NEW-VALUE or some suitable default value
+if NIL. If WAIT-P is non-NIL and the lock is in use, sleep until it
+is available"
(declare (type mutex lock) (optimize (speed 3)))
(let ((pid (current-thread-id)))
(unless new-value (setf new-value pid))
(let ((pid (current-thread-id))
old)
(unless new-value (setf new-value pid))
- (assert (not (eql new-value (mutex-value lock))))
+ (when (eql new-value (mutex-value lock))
+ (warn "recursive lock attempt ~S~%" lock))
(loop
(unless
(setf old (sb!vm::%instance-set-conditional lock 4 nil new-value))
(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)
+ (sb!ext:without-package-locks
+ (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))
(defun make-thread (function)
until (sb!sys:sap= thread (sb!sys:int-sap 0))
collect (funcall function thread))))
+(defun thread-sap-from-id (id)
+ (let ((thread (alien-sap (extern-alien "all_threads" (* t)))))
+ (loop
+ (when (sb!sys:sap= thread (sb!sys:int-sap 0)) (return nil))
+ (let ((pid (sb!sys:sap-ref-32 thread (* 4 sb!vm::thread-pid-slot))))
+ (when (= pid id) (return thread))
+ (setf thread (sb!sys:sap-ref-sap thread (* 4 sb!vm::thread-next-slot)))))))
+
+;;; internal use only. If you think you need to use this, 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
+(defun symbol-value-in-thread (symbol thread-id)
+ (let ((thread (thread-sap-from-id thread-id)))
+ (when thread
+ (let* ((index (sb!vm::symbol-tls-index symbol))
+ (tl-val (sb!sys:sap-ref-32 thread (* 4 index))))
+ (if (eql tl-val sb!vm::unbound-marker-widetag)
+ (sb!vm::symbol-global-value symbol)
+ (sb!kernel:make-lisp-obj tl-val))))))
+
;;;; 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 %delete-thread-from-session (tid session)
+ (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)
- (%delete-thread-from-session (current-thread-id))
+ (%delete-thread-from-session (current-thread-id) *session*)
(let ((*session* (new-session))) (funcall fn)))
(defmacro with-new-session (args &body forms)
`(labels ((,fb-name () ,@forms))
(call-with-new-session (function ,fb-name)))))
-;;; this is called from a C signal handler: some signals may be masked
+;;; Remove thread id TID from its session, if it has one. This is
+;;; called from C reap_dead_threads() so is run in the context of
+;;; whichever thread called that (usually after a GC), which may not have
+;;; any meaningful parent/child/sibling relationship with the dead thread
(defun handle-thread-exit (tid)
- "Remove thread id TID from the session, if it's there"
- (%delete-thread-from-session tid))
+ (let ((session (symbol-value-in-thread '*session* tid)))
+ (and session (%delete-thread-from-session tid session))))
(defun terminate-session ()
- "Kill all threads in session exept for this one. Does nothing if current
+ "Kill all threads in session except for this one. Does nothing if current
thread is not the foreground thread"
+ (reap-dead-threads)
(let* ((tid (current-thread-id))
(to-kill
(with-mutex ((session-lock *session*))