Question

我正在使用SBCL编写一个研究项目的脚本，这是我第一次尝试使用SB-TREAHD。每个线程将多次调用外部shell命令，为其使用sb-ext：run-program。

问题在于，无论何时出现ext：run-program，程序都会遇到死锁（我没有使用mutex这样的任何东西）。我试验了一段时间，找不到任何解决方案。仍然可以发生死锁的代码的简化版本如下：

(use-package :sb-thread)

;;; Global Settings
(defparameter *path-num* 4)
(defparameter *testing* nil)
(defparameter *training* nil)
(defparameter *shared-folder* "shared")
(defparameter *template* "template.conf")
(defparameter *pwd* (namestring (truename ".")))


;;; Utilities
(defmacro compose-file-name (&rest parts)
  "compose a filename under current *pwd*"
  `(concatenate 'string *pwd* 
        ,@(mapcar (lambda (x) `(format nil "/~a" ,x))
              parts)))

(defun run-command (command &optional args)
  "run a shell comamnd and reflect the stdout on screen."
  (let* ((process (sb-ext:run-program command args
                                     :output :stream
                                     :wait nil))
         (output (sb-ext:process-output process)))
    (loop for line = (read-line output nil)
       while line do (format t "~a~%" line))))



(setf *testing* '("1" "2" "3" "4"))
(setf *training* '("5" "6" "7" "8"))


(defun gen-conf (path-id target labeled)
  "Prepare the configuration file"
  (format t "[~a]: ~a~%" path-id target)
  (let ((current-dir (compose-file-name path-id)))
    (run-command "/bin/cp" (list "-f" (compose-file-name *shared-folder* *template*)
                                 (format nil "~a/Prediction.conf" current-dir)))
    (with-open-file (*standard-output* (format nil "~a/Prediction.conf" current-dir)
                           :direction :output
                           :if-exists :append)
      (format t "--estimate ~a~%" path-id))))


(defun first-iteration ()
  (loop for i below 20
       do (gen-conf (thread-name *current-thread*) (format nil "~a" i) (list "123" "456"))))


;;; main
(defun main ()
  (let ((child-threads (loop for i below *path-num*
                          collect (make-thread 
                   (lambda () (first-iteration))
                   :name (format nil "~a" i)))))
    (loop for th in child-threads
       do (join-thread th))))


(main)

其中in（主）4个线程被创建，并且每个线程将运行（第一次迭代），并且在（第一次迭代）中它多次调用（gen-conf），这涉及两者（sb-ext：run -program）和文件I / O.

我想也许死锁是因为错误地使用sb-thread，但仅仅通过查看SBCL手册我找不到正确的方法。任何建议都会有所帮助。

顺便说一下，要运行该程序，请获取http://pages.cs.wisc.edu/~breakds/thread.tar.gz，其中包含所有必需的目录/文件。

谢谢！

SBCL线程中的死锁

0 个答案: