ProcessManager.java

/**
 * NOTE: This copyright does *not* cover user programs that use HQ
 * program services by normal system calls through the application
 * program interfaces provided as part of the Hyperic Plug-in Development
 * Kit or the Hyperic Client Development Kit - this is merely considered
 * normal use of the program, and does *not* fall under the heading of
 *  "derived work".
 *
 *  Copyright (C) [2010], VMware, Inc.
 *  This file is part of HQ.
 *
 *  HQ is free software; you can redistribute it and/or modify
 *  it under the terms version 2 of the GNU General Public License as
 *  published by the Free Software Foundation. This program is distributed
 *  in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 *  even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 *  PARTICULAR PURPOSE. See the GNU General Public License for more
 *  details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 *
 */

package org.hyperic.bootstrap;

import org.hyperic.sigar.SigarException;

/**
 * Platform-independent component responsible for process execution and
 * obtaining process status
 * @author jhickey
 * 
 */
public interface ProcessManager {

    /**
     * 
     * @param pidFile The pidfile of the process to lookup
     * @return the PID of the process from the file ONLY if the process is
     *         running and the file is found. Else returns -1.
     * @throws SigarException If an error occurs querying for the process
     */
    long getPidFromPidFile(String pidFile) throws SigarException;

    /**
     * Performs a process kill(TERM)
     * @param pid The PID of the process to kill
     * @throws SigarException
     */
    void kill(long pid) throws SigarException;

    /**
     * Executes a process, blocking until process execution completes or a
     * timeout is reached.
     * @param commandLine The command line of the process to execute
     * @param workingDir The working dir from which to execute the process
     * @param suppressOutput If true, process out will not be
     *        printed. If false, process out will print to log.info and process
     *        error will print to log.err
     * @return The exit code of the process
     */
    int executeProcess(String[] commandLine, String workingDir, boolean suppressOutput, int timeout);

    /**
     * Executes a process, blocking until process execution completes or a
     * timeout is reached.
     * @param commandLine The command line of the process to execute
     * @param workingDir The working dir from which to execute the process
     * @param envVariables The process environment
     * @param suppressOutput If true, process out will not be
     *        printed. If false, process out will print to log.info and process
     *        error will print to log.err
     * @return The exit code of the process
     */
    int executeProcess(String[] commandLine, String workingDir, String[] envVariables,
                       boolean suppressOutput, int timeout);

    /**
     * Checks if a port is bound. Will sleep 2 seconds and continue trying until
     * port is bound or maxTries has been reached
     * @param port The port to check
     * @param maxTries The number of times to check if the port is not bound
     * @return true if port is bound sometime w/in maxTries * 2 seconds, false
     *         if not bound
     * @throws Exception
     */
    boolean isPortInUse(long port, int maxTries) throws Exception;
    
    /**
     * Gets a PID from a process query
     * @param ptql The PTQL query to use
     * @return The PID or -1 if not found
     * @throws SigarException
     */
    long getPidFromProcQuery(String ptql) throws SigarException;
    
    /**
     * Performs a process kill(KILL)
     * @param pid The process to kill
     * @throws SigarException
     */
    void forceKill(long pid) throws SigarException;
    
    /**
     * Waits 2 seconds * maxTries for the specified process to die
     * @param maxTries The number of times to check for the PID
     * @param pid The PID of the process to check
     * @return true if PID is no longer found
     * @throws Exception
     */
    boolean waitForProcessDeath(int maxTries, long pid) throws Exception;

}