Examples of org.apache.derbyTesting.junit.SpawnedProcess

org.apache.derbyTesting.junit.SpawnedProcess

Utility code that wraps a spawned process (Java Process object).

There are three main aspects handled by this class:

Draining the output streams of the process.
Happens automatically, the output gathered can be accessed with {@linkplain #getFailMessage}, {@linkplain #getFullServerError}, {@linkplain #getFullServerOutput}, and {@linkplain #getNextServerOutput}
Waiting for process completion, followed by cleanup (see {@linkplain #complete()} and {@linkplain #complete(long)})
Forcibly destroying a process that live too long, for instance if inter-process communication hangs. This happens automatically if a threshold value is exceeded.

Implementation notes: Active waiting is employed when waiting for the process to complete. This is considered acceptable since the expected usage pattern is to spawn the process, execute a set of tests, and then finally asking the process to shut down. Waiting for the process to complete is the last step, and a process typically lives only for a short period of time anyway (often only for seconds, seldom more than a few minutes).
Forcibly destroying processes that live too long makes the test run continue even when facing inter-process communication hangs. The prime example is when both the client and the server are waiting for the other party to send data. Since the timeout is very high this feature is intended to avoid automated test runs from hanging indefinitely, for instance due to environmental issues affecting the process.

    public void spawnProcess() throws Exception {
        String[] cmd = {
            "junit.textui.TestRunner", spawnedTestClass.getName()
        };


        SpawnedProcess proc =
            new SpawnedProcess(execJavaCmd(cmd), spawnedTestClass.getName());


        if (proc.complete() != 0) {
            fail(proc.getFailMessage("Test process failed"));
        }
    }

                     return result;
                 }
             }
            );
        
        SpawnedProcess spawned = new SpawnedProcess(serverProcess,
                commandSpecifics);
        
        // Ensure it completes without failures.
        assertEquals(0, spawned.complete());
        
        return spawned.getFullServerOutput();
    }

Examples of org.apache.derbyTesting.junit.SpawnedProcess

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