154
155
156
157
158
159
160
161
162
|
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
|
;; (define (debug:print . params) #f)
;; (define (debug:print-info . params) #f)
;;
;; (define (set-functions dbgp dbgpinfo)
;; (set! debug:print dbgp)
;; (set! debug:print-info dbgpinfo))
;; dot-locking egg seems not to work, using this for now
;; if lock is older than expire-time then remove it and try again
;; to get the lock
;;
(define (common:simple-file-lock fname #!key (expire-time 300))
(let ((fmod-time (handle-exceptions
ext
(current-seconds)
(file-modification-time fname))))
(if (file-exists? fname)
(if (> (- (current-seconds) fmod-time) expire-time)
(begin
(handle-exceptions exn #f (delete-file* fname))
(common:simple-file-lock fname expire-time: expire-time))
#f)
(let ((key-string (conc (get-host-name) "-" (current-process-id))))
(with-output-to-file fname
(lambda ()
(print key-string)))
(thread-sleep! 0.25)
(if (file-exists? fname)
(handle-exceptions exn
#f
(with-input-from-file fname
(lambda ()
(equal? key-string (read-line)))))
#f)))))
(define (common:simple-file-lock-and-wait fname #!key (expire-time 300))
(let ((end-time (+ expire-time (current-seconds))))
(let loop ((got-lock (common:simple-file-lock fname expire-time: expire-time)))
(if got-lock
#t
(if (> end-time (current-seconds))
(begin
(thread-sleep! 3)
(loop (common:simple-file-lock fname expire-time: expire-time)))
#f)))))
(define (common:simple-file-release-lock fname)
(handle-exceptions
exn
#f ;; I don't really care why this failed (at least for now)
(delete-file* fname)))
;; dot-locking egg seems not to work, using this for now
;; if lock is older than expire-time then remove it and try again
;; to get the lock
;;
(define (common:simple-file-lock fname #!key (expire-time 300))
(let ((fmod-time (handle-exceptions
ext
(current-seconds)
(file-modification-time fname))))
(if (file-exists? fname)
(if (> (- (current-seconds) fmod-time) expire-time)
(begin
(handle-exceptions exn #f (delete-file* fname))
(common:simple-file-lock fname expire-time: expire-time))
#f)
(let ((key-string (conc (get-host-name) "-" (current-process-id))))
(with-output-to-file fname
(lambda ()
(print key-string)))
(thread-sleep! 0.25)
(if (file-exists? fname)
(handle-exceptions exn
#f
(with-input-from-file fname
(lambda ()
(equal? key-string (read-line)))))
#f)))))
(define (common:simple-file-lock-and-wait fname #!key (expire-time 300))
(let ((end-time (+ expire-time (current-seconds))))
(let loop ((got-lock (common:simple-file-lock fname expire-time: expire-time)))
(if got-lock
#t
(if (> end-time (current-seconds))
(begin
(thread-sleep! 3)
(loop (common:simple-file-lock fname expire-time: expire-time)))
#f)))))
(define (common:simple-file-release-lock fname)
(handle-exceptions
exn
#f ;; I don't really care why this failed (at least for now)
(delete-file* fname)))
)
|