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package org.apache.cayenne.test.parallel;
/**
* Helper class allowing unit tests to wait till a code in question executes in
* a separate thread. There is still some element of uncertainty remains, since
* this implementation simply tries to give other threads enough time to
* execute, instead of watching for threads activity.
*
* <p>
* Note that result sampling is done every 300 ms., so if the test succeeds
* earlier, test case wouldn't have to wait for the whole time period specified
* by timeout.
* </p>
*
*/
public abstract class ParallelTestContainer {
protected abstract void assertResult() throws Exception;
public void runTest(long timeoutMs) throws Exception {
long checkEveryXMs;
int maxMumberOfChecks;
if (timeoutMs < 300) {
maxMumberOfChecks = 1;
checkEveryXMs = timeoutMs;
} else {
maxMumberOfChecks = Math.round(timeoutMs / 300.00f);
checkEveryXMs = 300;
}
// TODO: for things asserting that a certain event DID NOT happen
// we need a better implementation, that should probably sleep for
// the whole timeout interval, since otherwise we may have a false
// positive (i.e. assertion succeeded not because a certain thing did
// not happen, but rather cause it happened after the assertion was
// run).
// for now lets wait for at least one time slice to decrease
// the possibility of false positives
Thread.sleep(checkEveryXMs);
maxMumberOfChecks--;
for (int i = 0; i < maxMumberOfChecks; i++) {
try {
assertResult();
// success... return immediately
return;
} catch (Throwable th) {
// wait some more
Thread.sleep(checkEveryXMs);
}
}
// if it throws, it throws...
assertResult();
}
}