java - mHandler isn't set from within a synchronized block in Android SDK -


looking through android sdk framework source code, i've come across this:

 private final class gpslocationproviderthread extends thread {          public gpslocationproviderthread() {             super("gpslocationprovider");         }          public void run() {             process.setthreadpriority(process.thread_priority_background);             initialize();             looper.prepare();             mhandler = new providerhandler();             // signal when initialized , ready go             minitializedlatch.countdown();             looper.loop();         }     }

(this froyo's frameworks/base/location/java/com/android/internal/location/gpslocationprovider.java)

gpslocationproviderthread inner class of gpslocationprovider, , mhandler member instance variable of gpslocationprovider. variable set within thread's run() method, no synchronization applied, , mhandler not volatile.

why work? , if 99% of time work, it's not guaranteed work, , it's not practice. correct in understanding, or there subtle code i'm misunderstanding?

the thread created when provider created (in constructor), , minitializedlatch makes sure constructor proceeds once thread , running.

after point, mhandler created , valid, , since handler class' methods reentrant, system should thread-safe. handler, after all, class designed inter-thread communication.


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