id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	difficulty
1696	mutex-lock! doesn't always lock mutex	megane		"{{{
;; From C4 tests/mutex-test.scm
(import scheme)
(cond-expand
 (chicken-5 (import (chicken base)
		    (chicken type)
		    (chicken format)
		    srfi-18))
 (else (import chicken) (use srfi-18)))

(define-record-printer (mutex x out)
  (format out ""<mutex ~a ~a~a ~a (owner ~a) waiting ~a>""
	  (mutex-name x)
	  (if (##sys#slot x 5) ""LOCKED"" ""FREE"")
	  (if (##sys#slot x 4) ""/ABANDONED"" """")
	  (mutex-state x)
	  (if (##sys#slot x 2) (##sys#slot x 2) ""none"")
	  (##sys#slot x 3)
	  ))

(let ((m1 (make-mutex)))
  ;; (print m1)
  (mutex-lock! m1)
  (print m1)
  (print* ""l"")
  ;; (thread-sleep! 0.001)
  (let ((t1 (thread-start! (lambda ()
			     (print* ""t"")
			     (mutex-lock! m1 0.001)
			     (print ""\noh no, we got the mutex"")
			     (print m1)
			     (exit 1)))))
    (print* ""y"")
    (thread-yield!)
    (print* ""Y"")
    (when (eq? 'ready (##sys#slot t1 3)) ;; <- #3 thread state
      (print* ""X"")
      (thread-sleep! 1)
      (print* ""Z""))))

(print* ""."")

;; OK run:
;; lytY.<mutex mutex0 LOCKED #<thread: primordial> (owner #<thread: primordial>) waiting ()>

;; Failing run:
;; lytYX
;; oh no, we got the mutex
;; <mutex mutex0 LOCKED #<thread: primordial> (owner #<thread: primordial>) waiting ()>

}}}"	defect	new	major	someday	unknown	5.2.0		srfi-69 mutex race threads scheduler		insane