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Today, the editor will share with you the relevant knowledge points about how to use multithreading to start and stop services repeatedly in Android. The content is detailed and the logic is clear. I believe most people still know too much about this knowledge, so share this article for your reference. I hope you can get something after reading this article.

Android multithreading implements repeated start and stop services

In order to avoid deadlock in multithreaded environment, open invocation is generally advocated. Open invocation can avoid deadlock at the cost of losing atomicity. But sometimes it seems to be logically wrong.

For example:

Class A {private boolean mIsStarted; void start () {boolean changed = false; synchronized (this) {if (! mIsStarted) {mIsStarted = true; changed = false;} if (changed) {callBack.onStart ();} boolean isStarted () {sychronized (this) {return mIstarted;}} void stop () {boolean changed = false; synchronized (this) {if (mStarted) {mStarted = false; changed = true } if (changed) {callBack.onStop ();}

There is nothing wrong with this code in a single-threaded environment. However, strange phenomena can occur in a multithreaded environment.

In principle, onStart must be ahead of onStop, but this is not the case:

The steps are as follows:

Thread 1 start

Thread 2 stop

Thread 1

If (! mIsStarted) {mIsStarted = true; changed = false;}

Thread 2

Synchronized (this) {if (mStarted) {mStarted = false; changed = true;}} above is all the content of the article "how to use multithreading to start and stop services repeatedly in Android". Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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