While loop spins on field
Reports while
loops, which spin on the value of a non-volatile
field, waiting for it to be changed by another thread.
In addition to being potentially extremely CPU intensive when little work is done inside the loop, such loops likely have different semantics than intended. The Java Memory Model allows that loop to never complete even if another thread changes the field's value.
Example:
class SpinsOnField {
boolean ready = false;
void run() {
// the loop may never complete even after
// markAsReady call from the other thread
while (!ready) {
}
// do some work
}
void markAsReady() {
ready = true;
}
}
Additionally since Java 9, calling Thread.onSpinWait()
inside spin loop on a volatile
field is recommended, which may significantly improve performance on some hardware.
- By ID
Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.
GroovyWhileLoopSpinsOnField
Use the checkbox below to have this inspection report only empty while
loops.
Here you can find the description of settings available for the While loop spins on field inspection, and the reference of their default values.
Inspection Details | |
---|---|
By default bundled with: | |
Can be installed with plugin: | Groovy, 243.23126 |
Thanks for your feedback!