diff options
Diffstat (limited to 'src/main/java/org/junit/internal/requests/MemoizingRequest.java')
-rw-r--r-- | src/main/java/org/junit/internal/requests/MemoizingRequest.java | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/main/java/org/junit/internal/requests/MemoizingRequest.java b/src/main/java/org/junit/internal/requests/MemoizingRequest.java new file mode 100644 index 0000000..191c230 --- /dev/null +++ b/src/main/java/org/junit/internal/requests/MemoizingRequest.java @@ -0,0 +1,30 @@ +package org.junit.internal.requests; + +import java.util.concurrent.locks.Lock; +import java.util.concurrent.locks.ReentrantLock; + +import org.junit.runner.Request; +import org.junit.runner.Runner; + +abstract class MemoizingRequest extends Request { + private final Lock runnerLock = new ReentrantLock(); + private volatile Runner runner; + + @Override + public final Runner getRunner() { + if (runner == null) { + runnerLock.lock(); + try { + if (runner == null) { + runner = createRunner(); + } + } finally { + runnerLock.unlock(); + } + } + return runner; + } + + /** Creates the {@link Runner} to return from {@link #getRunner()}. Called at most once. */ + protected abstract Runner createRunner(); +} |