AgentAttacherInternal.java

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package org.glassfish.flashlight.impl.client;

import com.sun.enterprise.universal.io.SmartFile;
import com.sun.enterprise.universal.process.ProcessUtils;
import com.sun.tools.attach.VirtualMachine;
import java.io.File;
import java.util.logging.*;
import org.glassfish.flashlight.FlashlightLoggerInfo;
import static org.glassfish.flashlight.FlashlightLoggerInfo.*;
import static com.sun.enterprise.util.SystemPropertyConstants.INSTALL_ROOT_PROPERTY;

/**
 * created May 26, 2011
 * @author Byron Nevins
 */
final class AgentAttacherInternal {
    static boolean isAttached() {
        return isAttached;
    }

    static boolean attachAgent() {
        return attachAgent(-1, "");
    }

    static boolean attachAgent(int pid, String options) {
        try {
            if (isAttached)
                return true;

            if(pid < 0)
                pid = ProcessUtils.getPid();

            if (pid < 0) {
                logger.log(Level.WARNING, INVALID_PID);
                return false;
            }

            VirtualMachine vm = VirtualMachine.attach(String.valueOf(pid));
            String ir = System.getProperty(INSTALL_ROOT_PROPERTY);
            File dir = new File(ir, "lib" + File.separator + "monitor");

            if (!dir.isDirectory()) {
                logger.log(Level.WARNING, MISSING_AGENT_JAR_DIR, dir);
                return false;
            }

            File agentJar = new File(dir, "flashlight-agent.jar");

            if (!agentJar.isFile()) {
                logger.log(Level.WARNING, MISSING_AGENT_JAR, dir);
                return false;
            }

            vm.loadAgent(SmartFile.sanitize(agentJar.getPath()), options);
            isAttached = true;
        }
        catch (Throwable t) {
            logger.log(Level.WARNING, ATTACH_AGENT_EXCEPTION, t.getMessage());
            isAttached = false;
        }
        
        return isAttached;
    }
    private static final Object syncOnMe = new Object();
    private static final Logger logger = FlashlightLoggerInfo.getLogger();
    private static boolean isAttached = false;
}