yield(), sleep(0), wait(0,1) and parkNanos(1)
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yield(), sleep(0), wait(0,1) and parkNanos(1)
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On the surface these methods do the same thing in Java; Thread.yield(), Thread.sleep(0), Object.wait(0,1) and LockSupport.parkNanos(1) They all wait a sort period of time, but how much that is varies a surprising amount and between platforms.
Timing a short delay
The following code times how long it takes to repeatedly call those methods.import java.util.concurrent.locks.LockSupport;
public class Pausing {
public static void main(String... args) throws InterruptedException {
int repeat = 10000;
for (int i = 0; i < 3; i++) {
long time0 = System.nanoTime();
for (int j = 0; j < repeat; j++)
Thread.yield();
long time1 = System.nanoTime();
for (int j = 0; j < repeat; j++)
Thread.sleep(0);
long time2 = System.nanoTime();
synchronized (Thread.class) {
for (int j = 0; j < repeat/10; j++)
Thread.class.wait(0, 1);
}
long time3 = System.nanoTime();
for (int j = 0; j < repeat/10; j++)
LockSupport.parkNanos(1);
long time4 = System.nanoTime();
System.out.printf("The average time to yield %.1f μs, sleep(0) %.1f μs, " +
"wait(0,1) %.1f μs and LockSupport.parkNanos(1) %.1f μs%n",
(time1 - time0) / repeat / 1e3, (time2 - time1) / repeat / 1e3,
(time3 - time2) / (repeat/10) / 1e3, (time4 - time3) / (repeat/10) / 1e3);
}
}
}
On Windows 7
The average time to yield 0.3 μs, sleep(0) 0.6 μs, wait(0,1) 999.9 μs and LockSupport.parkNanos(1) 1000.0 μs The average time to yield 0.3 μs, sleep(0) 0.6 μs, wait(0,1) 999.5 μs and LockSupport.parkNanos(1) 1000.1 μs The average time to yield 0.2 μs, sleep(0) 0.5 μs, wait(0,1) 1000.0 μs and LockSupport.parkNanos(1) 1000.1 μs
On RHEL 5.x
The average time to yield 1.1 μs, sleep(0) 1.1 μs, wait(0,1) 2003.8 μs and LockSupport.parkNanos(1) 3.8 μs The average time to yield 1.1 μs, sleep(0) 1.1 μs, wait(0,1) 2004.8 μs and LockSupport.parkNanos(1) 3.4 μs The average time to yield 1.1 μs, sleep(0) 1.1 μs, wait(0,1) 2005.6 μs and LockSupport.parkNanos(1) 3.1 μs
In summary
If you want to wait for a short period of time, you can't assume that all these methods do the same thing, nor will be the same between platforms.Developers! Quickly and easily gain access to the tools and information you need! Explore, test and combine our data quality APIs at Melissa Developer Portal – home to tools that save time and boost revenue.
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