@@ -145,6 +145,7 @@ Threads and Executors
145145 - the future is completed and the callback is attached from the same thread pool?
146146 - [ Adding a callback to a ` CompletableFuture ` (` SettableFuture ` ) in non-async mode is justified?
147147 ] ( #cf-beware-non-async )
148+ - [ Is ` Thread.sleep() ` usage in spin-wait loop justified?] ( #thread-sleep )
148149
149150Parallel Streams
150151 - [ Parallel Stream computation takes more than 100us in total?] ( #justify-parallel-stream-use )
@@ -1170,6 +1171,37 @@ See also the Javadoc for [`ListenableFuture.addListener()`](
11701171https://guava.dev/releases/28.1-jre/api/docs/com/google/common/util/concurrent/ListenableFuture.html#addListener-java.lang.Runnable-java.util.concurrent.Executor-
11711172) describing this problem.
11721173
1174+ <a name =" thread-sleep " ></a >
1175+ [ #] ( #thread-sleep ) TE.8. Developers often use busy-wait pattern like
1176+ ``` java
1177+ class EventHandler {
1178+ volatile boolean eventNotificationNotReceived;
1179+ 1180+ void waitForEventAndHandleIt () {
1181+ while (eventNotificationNotReceived) {
1182+ Thread . sleep(TimeUnit . SECONDS. toMillis(1L ));
1183+ }
1184+ readAndProcessEvent();
1185+ }
1186+ 1187+ void readAndProcessEvent () {
1188+ // Read event from some source and process it
1189+ }
1190+ }
1191+ ```
1192+ If there is a busy wait loop, is it explained in a comment why it's needed in the specific case,
1193+ and that the costs and potential problems associated with busy waiting either don't apply in the specific case,
1194+ or are outweighed by the benefits?
1195+ 1196+ Pay attention that ` Thread.sleep() ` ** in certain cases** could be replaced with:
1197+ - synchronization primitive (like ` Semaphore ` )
1198+ - ` Object.wait() ` /` Object.notify() `
1199+ - ` Thread.yield() `
1200+ - ` Thread.onSpinWait() `
1201+ 1202+ The mentioned pattern is covered by IDEA's inspection "Busy wait" which is currently off by default.
1203+ It will be on by default when [ IDEA-226838] ( https://youtrack.jetbrains.com/issue/IDEA-226838 ) is fixed.
1204+ 11731205### Parallel Streams
11741206
11751207<a name =" justify-parallel-stream-use " ></a >
0 commit comments