diff options
Diffstat (limited to 'mcron-core.scm')
| -rw-r--r-- | mcron-core.scm | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/mcron-core.scm b/mcron-core.scm index 90e1da9..0aaacc6 100644 --- a/mcron-core.scm +++ b/mcron-core.scm @@ -40,10 +40,9 @@ ;; ;; (vector user next-time-function action environment displayable next-time) ;; -;; where action may be a string (indicating a shell command) or a list -;; (indicating scheme code) or a procedure, and the environment is an alist of +;; where action must be a procedure, and the environment is an alist of ;; modifications that need making to the UNIX environment before the action is -;; run. The next-time elements is the only one that is modified during the +;; run. The next-time element is the only one that is modified during the ;; running of a cron process (i.e. all the others are set once and for all at ;; configuration time). ;; @@ -158,16 +157,16 @@ -;; If the user has requested a schedule of jobs that will run, we provide the -;; information here and then get out. +;; Create a string containing a textual list of the next count jobs to run. ;; -;; Start by determining the number of time points in the future that output is -;; required for. This may be provided on the command line as a parameter to the -;; --schedule option, or else we assume a default of 8. Having determined this -;; count we enter a loop of displaying the next set of jobs to run, artificially +;; Enter a loop of displaying the next set of jobs to run, artificially ;; forwarding the time to the next time point (instead of waiting for it to ;; occur as we would do in a normal run of mcron), and recurse around the loop ;; count times. +;; +;; Note that this has the effect of mutating the job timings. Thus the program +;; must exit after calling this function; the internal data state will be left +;; unusable. (define (get-schedule count) (with-output-to-string @@ -219,6 +218,12 @@ ;; ones to run (may be more than one). Set an alarm and go to sleep. When we ;; wake, run the jobs and reap any children (old jobs) that have ;; completed. Repeat ad infinitum. +;; +;; Note that, if we wake ahead of time, it can only mean that a signal has been +;; sent by a crontab job to tell us to re-read a crontab file. In this case we +;; break out of the loop here, and let the main procedure deal with the +;; situation (it will eventually re-call this function, thus maintaining the +;; loop). (define (run-job-loop . fd-list) |