WeightWatcher.java

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package org.dcm4chee.task;

/**
 * The Weight Watcher coordinates tasks that consume a lot of memory, e.g. Compression and Decompression tasks.
 *
 * @author Hermann Czedik-Eysenberg <hermann-agfa@czedik.net>
 */
public interface WeightWatcher {

    /**
     * Executes the given task on the calling thread.
     * <p>
     * The execution might be blocked for a certain time to prevent the application from using too much memory.
     * <p>
     * For this to work correctly, it is important for the task to ensure that BEFORE the end of its <code>call</code>
     * method all the used memory is freed again (is eligible for garbage collection).
     *
     * @param task the memory consuming task
     * @param <V>  return type of the task
     *
     * @throws InterruptedException thrown if the task had to be blocked, but the blocking was interrupted
     * @throws Exception            exceptions thrown by the {@link MemoryConsumingTask#call} method
     */
    <V> V execute(MemoryConsumingTask<V> task) throws InterruptedException, Exception;

}