java - ReentrantLock -> lockInterruptibly() won't check interrupt state sometimes? -


recently i've been refactoring project "reentrantlock" simplify logic.

general idea is:

1. "main" runnable thread running on own
2. if in order, main thread wait on condition "nextstep"
3. when wrong happened, method "oncancel()" invoked by/in thread, forcing main thread throw interruptionexcpetion, shutdown occur

after tests, turned out own method:

dointerrupt();

never worked expected: forcing main thread enter "interruptedexception" clause , quit loop.

update-2:
i've added "is-interrupted" debug message output log lines, if turns out interrupt state "mysteriously" cleared one...

update:
lock , condition methods: 

       lock.lockinterruptibly();      condition.await();
seemed not checking interrupt state sometimes? .... javadoc reads: 
     ......     if current thread:      has interrupted status set on entry method; or      interrupted while acquiring lock,      interruptedexception thrown , current thread's interrupted status cleared.      ......

log see like: 
      [action] waiting completion...: 1  [is-interrupted:false]     >> debug ---> begin next loop     [is-interrupted:false]     [action] reset next iteration: 2   [is-interrupted:false]     [action] cancelling...                 [is-interrupted:false]     >> debug ---> interrupt           [is-interrupted:false]     >> debug ---> check.                   [is-interrupted:true]     [action] waiting completion...: 2  [is-interrupted:false]     >> debug ---> begin next loop     [is-interrupted:false]     [action] reset next iteration: 3   [is-interrupted:false]     [action] waiting completion...: 3  [is-interrupted:false]     >> debug ---> begin next loop     [is-interrupted:false]     [action] reset next iteration: 4   [is-interrupted:false]     [action] waiting completion...: 4     >> debug ---> begin next loop     [action] reset next iteration: 5     [action] waiting completion...: 5     >> debug ---> begin next loop     [action] reset next iteration: 6     ...... , on until == max     [info] main process has reached finish state.
means interrupt signal lost or not processed somehow...

there better approach? or fix of code logic @ least?

multi-thread experts???

here's code:

public class sbcstaskengine extends genericengine<sbcstask> implements xlistener {     private final reentrantlock     lock       = new reentrantlock();     private final condition         nextstep   = lock.newcondition();     private volatile thread         main       = null;     // else ...      // it's runnable "main"     @override     protected void run() {         try {             main = thread.currentthread();             // setting up... x between 1 ~ 10000             (int = 1; <= max; i++) {                 lock.lockinterruptibly();                 // work ...                 log("[action] waiting completion...: " + i);                 // long wait (could fast if task went south)                 nextstep.await();                 if (max == i) {                     isnormalcompletion = true;                 } else {                     log("[action] reset next iteration:" + (i+1));                     // reset work...                 }                 lock.unlock();             } // end of [for] loop         } catch (interruptedexception e) {             log("[event] process stopped singal.");         } {             try { lock.unlock(); } catch (throwable ignored) {}         }         log("[info] main process has reached finish state.");     }      private void dointerrupt() {         log(">> debug ---> interrupt");         if (main != null)             main.interrupt();             log(">> debug ---> check.");     }     /**     * implement: xlistener(series)     * instruct main process enter cancel sequence     *     * known-issue: duplicate call? sync on method? wait risk evaluation     */     @override     public void oncancel() {         log("[action] cancelling...");         dointerrupt();     }     /**     * implement: xlistener(series)     * proceed main thread next loop     *     * known-issue: signal might occur before "memebers" await on condition (happen-before?), take chance now...     */    @override    private void donotifynextstep() {        try {            lock.lockinterruptibly();            log(">> debug ---> begin next loop");            nextstep.signalall();        } catch (interruptedexception e) {            dointerrupt();        } {            try { lock.unlock(); } catch (throwable ignored) {}        }    } } // end of [sbcstaskengine] class


more info: java version used:

java version "1.6.0_26" java(tm) se runtime environment (build 1.6.0_26-b03) java hotspot(tm) 64-bit server vm (build 20.1-b02, mixed mode)

after careful examine every single method used in "process()", turned out there's method "swallowed" interruptionexception accident...

throw out exception, entire code/class works expected now~~~

huge "@hendalst" commented in post make me revise possible interruption leakage... said: "the code above works", root causing method inside comment area "//some work..." didn't post here...

, "@orionll" suggestion coding principles


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