tests/threads.impure.lisp

   1 ;;;; miscellaneous tests of thread stuff
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; While most of SBCL is derived from the CMU CL system, the test
   7 ;;;; files (like this one) were written from scratch after the fork
   8 ;;;; from CMU CL.
   9 ;;;
  10 ;;;; This software is in the public domain and is provided with
  11 ;;;; absoluely no warranty. See the COPYING and CREDITS files for
  12 ;;;; more information.
  13
  14 (in-package "SB-THREAD") ; this is white-box testing, really
  15
  16 (use-package :test-util)
  17 (use-package "ASSERTOID")
  18
  19 (setf sb-unix::*on-dangerous-select* :error)
  20
  21 (defun wait-for-threads (threads)
  22   (mapc (lambda (thread) (sb-thread:join-thread thread :default nil)) threads)
  23   (assert (not (some #'sb-thread:thread-alive-p threads))))
  24
  25 (assert (eql 1 (length (list-all-threads))))
  26
  27 (assert (eq *current-thread*
  28             (find (thread-name *current-thread*) (list-all-threads)
  29                   :key #'thread-name :test #'equal)))
  30
  31 (assert (thread-alive-p *current-thread*))
  32
  33 (let ((a 0))
  34   (interrupt-thread *current-thread* (lambda () (setq a 1)))
  35   (assert (eql a 1)))
  36
  37 (let ((spinlock (make-spinlock)))
  38   (with-spinlock (spinlock)))
  39
  40 (let ((mutex (make-mutex)))
  41   (with-mutex (mutex)
  42     mutex))
  43
  44 #-sb-thread (sb-ext:quit :unix-status 104)
  45
  46 ;;; compare-and-swap
  47
  48 (defmacro defincf (name accessor &rest args)
  49   `(defun ,name (x)
  50      (let* ((old (,accessor x ,@args))
  51          (new (1+ old)))
  52     (loop until (eq old (sb-ext:compare-and-swap (,accessor x ,@args) old new))
  53        do (setf old (,accessor x ,@args)
  54                 new (1+ old)))
  55     new)))
  56
  57 (defstruct cas-struct (slot 0))
  58
  59 (defincf incf-car car)
  60 (defincf incf-cdr cdr)
  61 (defincf incf-slot cas-struct-slot)
  62 (defincf incf-symbol-value symbol-value)
  63 (defincf incf-svref/1 svref 1)
  64 (defincf incf-svref/0 svref 0)
  65
  66 (defmacro def-test-cas (name init incf op)
  67   `(progn
  68      (defun ,name (n)
  69        (declare (fixnum n))
  70        (let* ((x ,init)
  71               (run nil)
  72               (threads
  73                (loop repeat 10
  74                      collect (sb-thread:make-thread
  75                               (lambda ()
  76                                 (loop until run)
  77                                 (loop repeat n do (,incf x)))))))
  78          (setf run t)
  79          (dolist (th threads)
  80            (sb-thread:join-thread th))
  81          (assert (= (,op x) (* 10 n)))))
  82      (,name 200000)))
  83
  84 (def-test-cas test-cas-car (cons 0 nil) incf-car car)
  85 (def-test-cas test-cas-cdr (cons nil 0) incf-cdr cdr)
  86 (def-test-cas test-cas-slot (make-cas-struct) incf-slot cas-struct-slot)
  87 (def-test-cas test-cas-value (let ((x '.x.))
  88                                (set x 0)
  89                                x)
  90   incf-symbol-value symbol-value)
  91 (def-test-cas test-cas-svref/0 (vector 0 nil) incf-svref/0 (lambda (x)
  92                                                              (svref x 0)))
  93 (def-test-cas test-cas-svref/1 (vector nil 0) incf-svref/1 (lambda (x)
  94                                                              (svref x 1)))
  95 (format t "~&compare-and-swap tests done~%")
  96
  97 (let ((old-threads (list-all-threads))
  98       (thread (make-thread (lambda ()
  99                              (assert (find *current-thread* *all-threads*))
 100                              (sleep 2))))
 101       (new-threads (list-all-threads)))
 102   (assert (thread-alive-p thread))
 103   (assert (eq thread (first new-threads)))
 104   (assert (= (1+ (length old-threads)) (length new-threads)))
 105   (sleep 3)
 106   (assert (not (thread-alive-p thread))))
 107
 108 (with-test (:name '(:join-thread :nlx :default))
 109   (let ((sym (gensym)))
 110     (assert (eq sym (join-thread (make-thread (lambda () (sb-ext:quit)))
 111                                  :default sym)))))
 112
 113 (with-test (:name '(:join-thread :nlx :error))
 114   (raises-error? (join-thread (make-thread (lambda () (sb-ext:quit))))))
 115
 116 (with-test (:name '(:join-thread :multiple-values))
 117   (assert (equal '(1 2 3)
 118                  (multiple-value-list
 119                   (join-thread (make-thread (lambda () (values 1 2 3))))))))
 120
 121 ;;; We had appalling scaling properties for a while.  Make sure they
 122 ;;; don't reappear.
 123 (defun scaling-test (function &optional (nthreads 5))
 124   "Execute FUNCTION with NTHREADS lurking to slow it down."
 125   (let ((queue (sb-thread:make-waitqueue))
 126         (mutex (sb-thread:make-mutex)))
 127     ;; Start NTHREADS idle threads.
 128     (dotimes (i nthreads)
 129       (sb-thread:make-thread (lambda ()
 130                                (with-mutex (mutex)
 131                                  (sb-thread:condition-wait queue mutex))
 132                                (sb-ext:quit))))
 133     (let ((start-time (get-internal-run-time)))
 134       (funcall function)
 135       (prog1 (- (get-internal-run-time) start-time)
 136         (sb-thread:condition-broadcast queue)))))
 137 (defun fact (n)
 138   "A function that does work with the CPU."
 139   (if (zerop n) 1 (* n (fact (1- n)))))
 140 (let ((work (lambda () (fact 15000))))
 141   (let ((zero (scaling-test work 0))
 142         (four (scaling-test work 4)))
 143     ;; a slightly weak assertion, but good enough for starters.
 144     (assert (< four (* 1.5 zero)))))
 145
 146 ;;; For one of the interupt-thread tests, we want a foreign function
 147 ;;; that does not make syscalls
 148
 149 (with-open-file (o "threads-foreign.c" :direction :output :if-exists :supersede)
 150   (format o "void loop_forever() { while(1) ; }~%"))
 151 (sb-ext:run-program
 152  #-sunos "cc" #+sunos "gcc"
 153  (or #+(or linux freebsd sunos) '(#+x86-64 "-fPIC"
 154                                   "-shared" "-o" "threads-foreign.so" "threads-foreign.c")
 155      #+darwin '(#+x86-64 "-arch" #+x86-64 "x86_64"
 156                 "-dynamiclib" "-o" "threads-foreign.so" "threads-foreign.c")
 157      (error "Missing shared library compilation options for this platform"))
 158  :search t)
 159 (sb-alien:load-shared-object "threads-foreign.so")
 160 (sb-alien:define-alien-routine loop-forever sb-alien:void)
 161 (delete-file "threads-foreign.c")
 162
 163 ;;; elementary "can we get a lock and release it again"
 164 (let ((l (make-mutex :name "foo"))
 165       (p *current-thread*))
 166   (assert (eql (mutex-value l) nil) nil "1")
 167   (sb-thread:get-mutex l)
 168   (assert (eql (mutex-value l) p) nil "3")
 169   (sb-thread:release-mutex l)
 170   (assert (eql (mutex-value l) nil) nil "5"))
 171
 172 (labels ((ours-p (value)
 173            (eq *current-thread* value)))
 174   (let ((l (make-mutex :name "rec")))
 175     (assert (eql (mutex-value l) nil) nil "1")
 176     (sb-thread:with-recursive-lock (l)
 177       (assert (ours-p (mutex-value l)) nil "3")
 178       (sb-thread:with-recursive-lock (l)
 179         (assert (ours-p (mutex-value l)) nil "4"))
 180       (assert (ours-p (mutex-value l)) nil "5"))
 181     (assert (eql (mutex-value l) nil) nil "6")))
 182
 183 (labels ((ours-p (value)
 184            (eq *current-thread* value)))
 185   (let ((l (make-spinlock :name "rec")))
 186     (assert (eql (spinlock-value l) nil) nil "1")
 187     (with-recursive-spinlock (l)
 188       (assert (ours-p (spinlock-value l)) nil "3")
 189       (with-recursive-spinlock (l)
 190         (assert (ours-p (spinlock-value l)) nil "4"))
 191       (assert (ours-p (spinlock-value l)) nil "5"))
 192     (assert (eql (spinlock-value l) nil) nil "6")))
 193
 194 (with-test (:name (:mutex :nesting-mutex-and-recursive-lock))
 195   (let ((l (make-mutex :name "a mutex")))
 196     (with-mutex (l)
 197       (with-recursive-lock (l)))))
 198
 199 (with-test (:name (:spinlock :nesting-spinlock-and-recursive-spinlock))
 200   (let ((l (make-spinlock :name "a spinlock")))
 201     (with-spinlock (l)
 202       (with-recursive-spinlock (l)))))
 203
 204 (let ((l (make-spinlock :name "spinlock")))
 205   (assert (eql (spinlock-value l) nil) ((spinlock-value l))
 206           "spinlock not free (1)")
 207   (with-spinlock (l)
 208     (assert (eql (spinlock-value l) *current-thread*) ((spinlock-value l))
 209             "spinlock not taken"))
 210   (assert (eql (spinlock-value l) nil) ((spinlock-value l))
 211           "spinlock not free (2)"))
 212
 213 ;; test that SLEEP actually sleeps for at least the given time, even
 214 ;; if interrupted by another thread exiting/a gc/anything
 215 (let ((start-time (get-universal-time)))
 216   (make-thread (lambda () (sleep 1) (sb-ext:gc :full t)))
 217   (sleep 5)
 218   (assert (>= (get-universal-time) (+ 5 start-time))))
 219
 220
 221 (let ((queue (make-waitqueue :name "queue"))
 222       (lock (make-mutex :name "lock"))
 223       (n 0))
 224   (labels ((in-new-thread ()
 225              (with-mutex (lock)
 226                (assert (eql (mutex-value lock) *current-thread*))
 227                (format t "~A got mutex~%" *current-thread*)
 228                ;; now drop it and sleep
 229                (condition-wait queue lock)
 230                ;; after waking we should have the lock again
 231                (assert (eql (mutex-value lock) *current-thread*))
 232                (assert (eql n 1))
 233                (decf n))))
 234     (make-thread #'in-new-thread)
 235     (sleep 2)                           ; give it  a chance to start
 236     ;; check the lock is free while it's asleep
 237     (format t "parent thread ~A~%" *current-thread*)
 238     (assert (eql (mutex-value lock) nil))
 239     (with-mutex (lock)
 240       (incf n)
 241       (condition-notify queue))
 242     (sleep 1)))
 243
 244 (let ((queue (make-waitqueue :name "queue"))
 245       (lock (make-mutex :name "lock")))
 246   (labels ((ours-p (value)
 247              (eq *current-thread* value))
 248            (in-new-thread ()
 249              (with-recursive-lock (lock)
 250                (assert (ours-p (mutex-value lock)))
 251                (format t "~A got mutex~%" (mutex-value lock))
 252                ;; now drop it and sleep
 253                (condition-wait queue lock)
 254                ;; after waking we should have the lock again
 255                (format t "woken, ~A got mutex~%" (mutex-value lock))
 256                (assert (ours-p (mutex-value lock))))))
 257     (make-thread #'in-new-thread)
 258     (sleep 2)                           ; give it  a chance to start
 259     ;; check the lock is free while it's asleep
 260     (format t "parent thread ~A~%" *current-thread*)
 261     (assert (eql (mutex-value lock) nil))
 262     (with-recursive-lock (lock)
 263       (condition-notify queue))
 264     (sleep 1)))
 265
 266 (let ((mutex (make-mutex :name "contended")))
 267   (labels ((run ()
 268              (let ((me *current-thread*))
 269                (dotimes (i 100)
 270                  (with-mutex (mutex)
 271                    (sleep .03)
 272                    (assert (eql (mutex-value mutex) me)))
 273                  (assert (not (eql (mutex-value mutex) me))))
 274                (format t "done ~A~%" *current-thread*))))
 275     (let ((kid1 (make-thread #'run))
 276           (kid2 (make-thread #'run)))
 277       (format t "contention ~A ~A~%" kid1 kid2)
 278       (wait-for-threads (list kid1 kid2)))))
 279
 280 ;;; semaphores
 281
 282 (defmacro raises-timeout-p (&body body)
 283   `(handler-case (progn (progn ,@body) nil)
 284     (sb-ext:timeout () t)))
 285
 286 (with-test (:name (:semaphore :wait-forever))
 287   (let ((sem (make-semaphore :count 0)))
 288     (assert (raises-timeout-p
 289               (sb-ext:with-timeout 0.1
 290                 (wait-on-semaphore sem))))))
 291
 292 (with-test (:name (:semaphore :initial-count))
 293   (let ((sem (make-semaphore :count 1)))
 294     (sb-ext:with-timeout 0.1
 295       (wait-on-semaphore sem))))
 296
 297 (with-test (:name (:semaphore :wait-then-signal))
 298   (let ((sem (make-semaphore))
 299         (signalled-p nil))
 300     (make-thread (lambda ()
 301                    (sleep 0.1)
 302                    (setq signalled-p t)
 303                    (signal-semaphore sem)))
 304     (wait-on-semaphore sem)
 305     (assert signalled-p)))
 306
 307 (with-test (:name (:semaphore :signal-then-wait))
 308   (let ((sem (make-semaphore))
 309         (signalled-p nil))
 310     (make-thread (lambda ()
 311                    (signal-semaphore sem)
 312                    (setq signalled-p t)))
 313     (loop until signalled-p)
 314     (wait-on-semaphore sem)
 315     (assert signalled-p)))
 316
 317 (with-test (:name (:semaphore :multiple-signals))
 318   (let* ((sem (make-semaphore :count 5))
 319          (threads (loop repeat 20
 320                         collect (make-thread (lambda ()
 321                                                (wait-on-semaphore sem))))))
 322     (flet ((count-live-threads ()
 323              (count-if #'thread-alive-p threads)))
 324       (sleep 0.5)
 325       (assert (= 15 (count-live-threads)))
 326       (signal-semaphore sem 10)
 327       (sleep 0.5)
 328       (assert (= 5 (count-live-threads)))
 329       (signal-semaphore sem 3)
 330       (sleep 0.5)
 331       (assert (= 2 (count-live-threads)))
 332       (signal-semaphore sem 4)
 333       (sleep 0.5)
 334       (assert (= 0 (count-live-threads))))))
 335
 336 (format t "~&semaphore tests done~%")
 337
 338 (defun test-interrupt (function-to-interrupt &optional quit-p)
 339   (let ((child  (make-thread function-to-interrupt)))
 340     ;;(format t "gdb ./src/runtime/sbcl ~A~%attach ~A~%" child child)
 341     (sleep 2)
 342     (format t "interrupting child ~A~%" child)
 343     (interrupt-thread child
 344                       (lambda ()
 345                         (format t "child pid ~A~%" *current-thread*)
 346                         (when quit-p (sb-ext:quit))))
 347     (sleep 1)
 348     child))
 349
 350 ;; separate tests for (a) interrupting Lisp code, (b) C code, (c) a syscall,
 351 ;; (d) waiting on a lock, (e) some code which we hope is likely to be
 352 ;; in pseudo-atomic
 353
 354 (let ((child (test-interrupt (lambda () (loop)))))  (terminate-thread child))
 355
 356 (test-interrupt #'loop-forever :quit)
 357
 358 (let ((child (test-interrupt (lambda () (loop (sleep 2000))))))
 359   (terminate-thread child)
 360   (wait-for-threads (list child)))
 361
 362 (let ((lock (make-mutex :name "loctite"))
 363       child)
 364   (with-mutex (lock)
 365     (setf child (test-interrupt
 366                  (lambda ()
 367                    (with-mutex (lock)
 368                      (assert (eql (mutex-value lock) *current-thread*)))
 369                    (assert (not (eql (mutex-value lock) *current-thread*)))
 370                    (sleep 10))))
 371     ;;hold onto lock for long enough that child can't get it immediately
 372     (sleep 5)
 373     (interrupt-thread child (lambda () (format t "l ~A~%" (mutex-value lock))))
 374     (format t "parent releasing lock~%"))
 375   (terminate-thread child)
 376   (wait-for-threads (list child)))
 377
 378 (format t "~&locking test done~%")
 379
 380 (defun alloc-stuff () (copy-list '(1 2 3 4 5)))
 381
 382 (progn
 383   (let ((thread (sb-thread:make-thread (lambda () (loop (alloc-stuff))))))
 384     (let ((killers
 385            (loop repeat 4 collect
 386                  (sb-thread:make-thread
 387                   (lambda ()
 388                     (loop repeat 25 do
 389                           (sleep (random 0.1d0))
 390                           (princ ".")
 391                           (force-output)
 392                           (sb-thread:interrupt-thread thread (lambda ()))))))))
 393       (wait-for-threads killers)
 394       (sb-thread:terminate-thread thread)
 395       (wait-for-threads (list thread))))
 396   (sb-ext:gc :full t))
 397
 398 (format t "~&multi interrupt test done~%")
 399
 400 (let ((c (make-thread (lambda () (loop (alloc-stuff))))))
 401   ;; NB this only works on x86: other ports don't have a symbol for
 402   ;; pseudo-atomic atomicity
 403   (dotimes (i 100)
 404     (sleep (random 0.1d0))
 405     (interrupt-thread c
 406                       (lambda ()
 407                         (princ ".") (force-output)
 408                         (assert (thread-alive-p *current-thread*))
 409                         (assert
 410                          (not (logbitp 0 SB-KERNEL:*PSEUDO-ATOMIC-BITS*))))))
 411   (terminate-thread c)
 412   (wait-for-threads (list c)))
 413
 414 (format t "~&interrupt test done~%")
 415
 416 (defparameter *interrupt-count* 0)
 417
 418 (declaim (notinline check-interrupt-count))
 419 (defun check-interrupt-count (i)
 420   (declare (optimize (debug 1) (speed 1)))
 421   ;; This used to lose if eflags were not restored after an interrupt.
 422   (unless (typep i 'fixnum)
 423     (error "!!!!!!!!!!!")))
 424
 425 (let ((c (make-thread
 426           (lambda ()
 427             (handler-bind ((error #'(lambda (cond)
 428                                       (princ cond)
 429                                       (sb-debug:backtrace
 430                                        most-positive-fixnum))))
 431               (loop (check-interrupt-count *interrupt-count*)))))))
 432   (let ((func (lambda ()
 433                 (princ ".")
 434                 (force-output)
 435                 (sb-impl::atomic-incf/symbol *interrupt-count*))))
 436     (setq *interrupt-count* 0)
 437     (dotimes (i 100)
 438       (sleep (random 0.1d0))
 439       (interrupt-thread c func))
 440     (loop until (= *interrupt-count* 100) do (sleep 0.1))
 441     (terminate-thread c)
 442     (wait-for-threads (list c))))
 443
 444 (format t "~&interrupt count test done~%")
 445
 446 (let (a-done b-done)
 447   (make-thread (lambda ()
 448                  (dotimes (i 100)
 449                    (sb-ext:gc) (princ "\\") (force-output))
 450                  (setf a-done t)))
 451   (make-thread (lambda ()
 452                  (dotimes (i 25)
 453                    (sb-ext:gc :full t)
 454                    (princ "/") (force-output))
 455                  (setf b-done t)))
 456   (loop
 457    (when (and a-done b-done) (return))
 458    (sleep 1)))
 459
 460 (terpri)
 461
 462 (defun waste (&optional (n 100000))
 463   (loop repeat n do (make-string 16384)))
 464
 465 (loop for i below 100 do
 466       (princ "!")
 467       (force-output)
 468       (sb-thread:make-thread
 469        #'(lambda ()
 470            (waste)))
 471       (waste)
 472       (sb-ext:gc))
 473
 474 (terpri)
 475
 476 (defparameter *aaa* nil)
 477 (loop for i below 100 do
 478       (princ "!")
 479       (force-output)
 480       (sb-thread:make-thread
 481        #'(lambda ()
 482            (let ((*aaa* (waste)))
 483              (waste))))
 484       (let ((*aaa* (waste)))
 485         (waste))
 486       (sb-ext:gc))
 487
 488 (format t "~&gc test done~%")
 489
 490 ;; this used to deadlock on session-lock
 491 (sb-thread:make-thread (lambda () (sb-ext:gc)))
 492 ;; expose thread creation races by exiting quickly
 493 (sb-thread:make-thread (lambda ()))
 494
 495 (defun exercise-syscall (fn reference-errno)
 496   (sb-thread:make-thread
 497    (lambda ()
 498      (loop do
 499           (funcall fn)
 500           (let ((errno (sb-unix::get-errno)))
 501             (sleep (random 0.1d0))
 502             (unless (eql errno reference-errno)
 503               (format t "Got errno: ~A (~A) instead of ~A~%"
 504                       errno
 505                       (sb-unix::strerror)
 506                       reference-errno)
 507               (force-output)
 508               (sb-ext:quit :unix-status 1)))))))
 509
 510 ;; (nanosleep -1 0) does not fail on FreeBSD
 511 (let* (#-freebsd
 512        (nanosleep-errno (progn
 513                           (sb-unix:nanosleep -1 0)
 514                           (sb-unix::get-errno)))
 515        (open-errno (progn
 516                      (open "no-such-file"
 517                            :if-does-not-exist nil)
 518                      (sb-unix::get-errno)))
 519        (threads
 520         (list
 521          #-freebsd
 522          (exercise-syscall (lambda () (sb-unix:nanosleep -1 0)) nanosleep-errno)
 523          (exercise-syscall (lambda () (open "no-such-file"
 524                                             :if-does-not-exist nil))
 525                            open-errno)
 526          (sb-thread:make-thread (lambda () (loop (sb-ext:gc) (sleep 1)))))))
 527   (sleep 10)
 528   (princ "terminating threads")
 529   (dolist (thread threads)
 530     (sb-thread:terminate-thread thread)))
 531
 532 (format t "~&errno test done~%")
 533
 534 (loop repeat 100 do
 535       (let ((thread (sb-thread:make-thread (lambda () (sleep 0.1)))))
 536         (sb-thread:interrupt-thread
 537          thread
 538          (lambda ()
 539            (assert (find-restart 'sb-thread:terminate-thread))))))
 540
 541 (sb-ext:gc :full t)
 542
 543 (format t "~&thread startup sigmask test done~%")
 544
 545 ;; FIXME: What is this supposed to test?
 546 (sb-debug::enable-debugger)
 547 (let* ((main-thread *current-thread*)
 548        (interruptor-thread
 549         (make-thread (lambda ()
 550                        (sleep 2)
 551                        (interrupt-thread main-thread #'break)
 552                        (sleep 2)
 553                        (interrupt-thread main-thread #'continue))
 554                      :name "interruptor")))
 555   (with-session-lock (*session*)
 556     (sleep 3))
 557   (loop while (thread-alive-p interruptor-thread)))
 558
 559 (format t "~&session lock test done~%")
 560
 561 (loop repeat 20 do
 562       (wait-for-threads
 563        (loop for i below 100 collect
 564              (sb-thread:make-thread (lambda ())))))
 565
 566 (format t "~&creation test done~%")
 567
 568 ;; interrupt handlers are per-thread with pthreads, make sure the
 569 ;; handler installed in one thread is global
 570 (sb-thread:make-thread
 571  (lambda ()
 572    (sb-ext:run-program "sleep" '("1") :search t :wait nil)))
 573
 574 ;;;; Binding stack safety
 575
 576 (defparameter *x* nil)
 577 (defparameter *n-gcs-requested* 0)
 578 (defparameter *n-gcs-done* 0)
 579
 580 (let ((counter 0))
 581   (defun make-something-big ()
 582     (let ((x (make-string 32000)))
 583       (incf counter)
 584       (let ((counter counter))
 585         (sb-ext:finalize x (lambda () (format t " ~S" counter)
 586                                    (force-output)))))))
 587
 588 (defmacro wait-for-gc ()
 589   `(progn
 590      (incf *n-gcs-requested*)
 591      (loop while (< *n-gcs-done* *n-gcs-requested*))))
 592
 593 (defun send-gc ()
 594   (loop until (< *n-gcs-done* *n-gcs-requested*))
 595   (format t "G")
 596   (force-output)
 597   (sb-ext:gc)
 598   (incf *n-gcs-done*))
 599
 600 (defun exercise-binding ()
 601   (loop
 602    (let ((*x* (make-something-big)))
 603      (let ((*x* 42))
 604        ;; at this point the binding stack looks like this:
 605        ;; NO-TLS-VALUE-MARKER, *x*, SOMETHING, *x*
 606        t))
 607    (wait-for-gc)
 608    ;; sig_stop_for_gc_handler binds FREE_INTERRUPT_CONTEXT_INDEX. By
 609    ;; now SOMETHING is gc'ed and the binding stack looks like this: 0,
 610    ;; 0, SOMETHING, 0 (because the symbol slots are zeroed on
 611    ;; unbinding but values are not).
 612    (let ((*x* nil))
 613      ;; bump bsp as if a BIND had just started
 614      (incf sb-vm::*binding-stack-pointer* 2)
 615      (wait-for-gc)
 616      (decf sb-vm::*binding-stack-pointer* 2))))
 617
 618 (with-test (:name (:binding-stack-gc-safety))
 619   (let (threads)
 620     (unwind-protect
 621          (progn
 622            (push (sb-thread:make-thread #'exercise-binding) threads)
 623            (push (sb-thread:make-thread (lambda ()
 624                                           (loop
 625                                            (sleep 0.1)
 626                                            (send-gc))))
 627                  threads)
 628            (sleep 4))
 629       (mapc #'sb-thread:terminate-thread threads))))
 630
 631 (format t "~&binding test done~%")
 632
 633 ;; Try to corrupt the NEXT-VECTOR. Operations on a hash table with a
 634 ;; cyclic NEXT-VECTOR can loop endlessly in a WITHOUT-GCING form
 635 ;; causing the next gc hang SBCL.
 636 (with-test (:name (:hash-table-thread-safety))
 637   (let* ((hash (make-hash-table))
 638          (threads (list (sb-thread:make-thread
 639                          (lambda ()
 640                            (loop
 641                             ;;(princ "1") (force-output)
 642                             (setf (gethash (random 100) hash) 'h))))
 643                         (sb-thread:make-thread
 644                          (lambda ()
 645                            (loop
 646                             ;;(princ "2") (force-output)
 647                             (remhash (random 100) hash))))
 648                         (sb-thread:make-thread
 649                          (lambda ()
 650                            (loop
 651                             (sleep (random 1.0))
 652                             (sb-ext:gc :full t)))))))
 653     (unwind-protect
 654          (sleep 5)
 655       (mapc #'sb-thread:terminate-thread threads))))
 656
 657 (format t "~&hash table test done~%")
 658 #|  ;; a cll post from eric marsden
 659 | (defun crash ()
 660 |   (setq *debugger-hook*
 661 |         (lambda (condition old-debugger-hook)
 662 |           (debug:backtrace 10)
 663 |           (unix:unix-exit 2)))
 664 |   #+live-dangerously
 665 |   (mp::start-sigalrm-yield)
 666 |   (flet ((roomy () (loop (with-output-to-string (*standard-output*) (room)))))
 667 |     (mp:make-process #'roomy)
 668 |     (mp:make-process #'roomy)))
 669 |#
 670
 671 (with-test (:name (:condition-variable :notify-multiple))
 672   (flet ((tester (notify-fun)
 673            (let ((queue (make-waitqueue :name "queue"))
 674                  (lock (make-mutex :name "lock"))
 675                  (data nil))
 676              (labels ((test (x)
 677                         (loop
 678                            (with-mutex (lock)
 679                              (format t "condition-wait ~a~%" x)
 680                              (force-output)
 681                              (condition-wait queue lock)
 682                              (format t "woke up ~a~%" x)
 683                              (force-output)
 684                              (push x data)))))
 685                (let ((threads (loop for x from 1 to 10
 686                                     collect
 687                                     (let ((x x))
 688                                       (sb-thread:make-thread (lambda ()
 689                                                                (test x)))))))
 690                  (sleep 5)
 691                  (with-mutex (lock)
 692                    (funcall notify-fun queue))
 693                  (sleep 5)
 694                  (mapcar #'terminate-thread threads)
 695                  ;; Check that all threads woke up at least once
 696                  (assert (= (length (remove-duplicates data)) 10)))))))
 697     (tester (lambda (queue)
 698               (format t "~&(condition-notify queue 10)~%")
 699               (force-output)
 700               (condition-notify queue 10)))
 701     (tester (lambda (queue)
 702               (format t "~&(condition-broadcast queue)~%")
 703               (force-output)
 704               (condition-broadcast queue)))))
 705
 706 (format t "waitqueue wakeup tests done~%")
 707
 708 (with-test (:name (:mutex :finalization))
 709   (let ((a nil))
 710     (dotimes (i 500000)
 711       (setf a (make-mutex)))))
 712
 713 (format t "mutex finalization test done~%")
 714
 715 ;;; Check that INFO is thread-safe, at least when we're just doing reads.
 716
 717 (let* ((symbols (loop repeat 10000 collect (gensym)))
 718        (functions (loop for (symbol . rest) on symbols
 719                         for next = (car rest)
 720                         for fun = (let ((next next))
 721                                     (lambda (n)
 722                                       (if next
 723                                           (funcall next (1- n))
 724                                           n)))
 725                         do (setf (symbol-function symbol) fun)
 726                         collect fun)))
 727   (defun infodb-test ()
 728     (funcall (car functions) 9999)))
 729
 730 (with-test (:name (:infodb :read))
 731   (let* ((ok t)
 732          (threads (loop for i from 0 to 10
 733                         collect (sb-thread:make-thread
 734                                  (lambda ()
 735                                    (dotimes (j 100)
 736                                      (write-char #\-)
 737                                      (finish-output)
 738                                      (let ((n (infodb-test)))
 739                                        (unless (zerop n)
 740                                          (setf ok nil)
 741                                          (format t "N != 0 (~A)~%" n)
 742                                          (sb-ext:quit)))))))))
 743     (wait-for-threads threads)
 744     (assert ok)))
 745
 746 (format t "infodb test done~%")
 747
 748 (with-test (:name (:backtrace))
 749   ;; Printing backtraces from several threads at once used to hang the
 750   ;; whole SBCL process (discovered by accident due to a timer.impure
 751   ;; test misbehaving). The cause was that packages weren't even
 752   ;; thread-safe for only doing FIND-SYMBOL, and while printing
 753   ;; backtraces a loot of symbol lookups need to be done due to
 754   ;; *PRINT-ESCAPE*.
 755   (let* ((threads (loop repeat 10
 756                         collect (sb-thread:make-thread
 757                                  (lambda ()
 758                                    (dotimes (i 1000)
 759                                      (with-output-to-string (*debug-io*)
 760                                        (sb-debug::backtrace 10))))))))
 761     (wait-for-threads threads)))
 762
 763 (format t "backtrace test done~%")
 764
 765 (format t "~&starting gc deadlock test: WARNING: THIS TEST WILL HANG ON FAILURE!~%")
 766
 767 (with-test (:name (:gc-deadlock))
 768   ;; Prior to 0.9.16.46 thread exit potentially deadlocked the
 769   ;; GC due to *all-threads-lock* and session lock. On earlier
 770   ;; versions and at least on one specific box this test is good enough
 771   ;; to catch that typically well before the 1500th iteration.
 772   (loop
 773      with i = 0
 774      with n = 3000
 775      while (< i n)
 776      do
 777        (incf i)
 778        (when (zerop (mod i 100))
 779          (write-char #\.)
 780          (force-output))
 781        (handler-case
 782            (if (oddp i)
 783                (sb-thread:make-thread
 784                 (lambda ()
 785                   (sleep (random 0.001)))
 786                 :name (list :sleep i))
 787                (sb-thread:make-thread
 788                 (lambda ()
 789                   ;; KLUDGE: what we are doing here is explicit,
 790                   ;; but the same can happen because of a regular
 791                   ;; MAKE-THREAD or LIST-ALL-THREADS, and various
 792                   ;; session functions.
 793                   (sb-thread:with-mutex (sb-thread::*all-threads-lock*)
 794                     (sb-thread::with-session-lock (sb-thread::*session*)
 795                       (sb-ext:gc))))
 796                 :name (list :gc i)))
 797          (error (e)
 798            (format t "~%error creating thread ~D: ~A -- backing off for retry~%" i e)
 799            (sleep 0.1)
 800            (incf i)))))
 801
 802 (format t "~&gc deadlock test done~%")
 803 \f
 804 (let ((count (make-array 8 :initial-element 0)))
 805   (defun closure-one ()
 806     (declare (optimize safety))
 807     (values (incf (aref count 0)) (incf (aref count 1))
 808             (incf (aref count 2)) (incf (aref count 3))
 809             (incf (aref count 4)) (incf (aref count 5))
 810             (incf (aref count 6)) (incf (aref count 7))))
 811   (defun no-optimizing-away-closure-one ()
 812     (setf count (make-array 8 :initial-element 0))))
 813
 814 (defstruct box
 815   (count 0))
 816
 817 (let ((one (make-box))
 818       (two (make-box))
 819       (three (make-box)))
 820   (defun closure-two ()
 821     (declare (optimize safety))
 822     (values (incf (box-count one)) (incf (box-count two)) (incf (box-count three))))
 823   (defun no-optimizing-away-closure-two ()
 824     (setf one (make-box)
 825           two (make-box)
 826           three (make-box))))
 827
 828 (with-test (:name (:funcallable-instances))
 829   ;; the funcallable-instance implementation used not to be threadsafe
 830   ;; against setting the funcallable-instance function to a closure
 831   ;; (because the code and lexenv were set separately).
 832   (let ((fun (sb-kernel:%make-funcallable-instance 0))
 833         (condition nil))
 834     (setf (sb-kernel:funcallable-instance-fun fun) #'closure-one)
 835     (flet ((changer ()
 836              (loop (setf (sb-kernel:funcallable-instance-fun fun) #'closure-one)
 837                    (setf (sb-kernel:funcallable-instance-fun fun) #'closure-two)))
 838            (test ()
 839              (handler-case (loop (funcall fun))
 840                (serious-condition (c) (setf condition c)))))
 841       (let ((changer (make-thread #'changer))
 842             (test (make-thread #'test)))
 843         (handler-case
 844             (progn
 845               ;; The two closures above are fairly carefully crafted
 846               ;; so that if given the wrong lexenv they will tend to
 847               ;; do some serious damage, but it is of course difficult
 848               ;; to predict where the various bits and pieces will be
 849               ;; allocated.  Five seconds failed fairly reliably on
 850               ;; both my x86 and x86-64 systems.  -- CSR, 2006-09-27.
 851               (sb-ext:with-timeout 5
 852                 (wait-for-threads (list test)))
 853               (error "~@<test thread got condition:~2I~_~A~@:>" condition))
 854           (sb-ext:timeout ()
 855             (terminate-thread changer)
 856             (terminate-thread test)
 857             (wait-for-threads (list changer test))))))))
 858
 859 (format t "~&funcallable-instance test done~%")
 860
 861 (defun random-type (n)
 862   `(integer ,(random n) ,(+ n (random n))))
 863
 864 (defun subtypep-hash-cache-test ()
 865   (dotimes (i 10000)
 866     (let ((type1 (random-type 500))
 867           (type2 (random-type 500)))
 868       (let ((a (subtypep type1 type2)))
 869         (dotimes (i 100)
 870           (assert (eq (subtypep type1 type2) a))))))
 871   (format t "ok~%")
 872   (force-output))
 873
 874 (with-test (:name '(:hash-cache :subtypep))
 875   (dotimes (i 10)
 876     (sb-thread:make-thread #'subtypep-hash-cache-test)))
 877
 878 (format t "hash-cache tests done~%")