title: Java JVMTI doesn't work alongside -Xdebug -Xrunjdwp
body: <p>I spent the last 4 hours trying to set up Eclipse TPTP memory
  profiling on a Tomcat instance that must be run remotely (i.e. not in
  Eclipse).  This should be possible according to the TPTP and Agent
  Controller docs.</p>
  
  <p>I installed the TPTP components (4.6.0) into my Eclipse (Galileo)
  workbench, along with the Agent Controller according to the
  instructions on the website.  To enable the agent, I added the
  following options to the command line that starts the Tomcat instance:</p>
  
  <pre><code>-agentlib:JPIBootLoader=JPIAgent:server=enabled;HeapProf:allocsites=true
  </code></pre>
  
  <p>and added the following directories to the front of the PATH:</p>
  
  <pre><code>D:\dev\tools\ac\plugins\org.eclipse.tptp.javaprofiler
  D:\dev\tools\ac\bin
  </code></pre>
  
  <p>When attempting to start Tomcat I consistently got the following error
  message:</p>
  
  <pre><code>ERROR: JDWP unable to get necessary JVMTI capabilities. ["debugInit.c",L279]
  </code></pre>
  
  <p>I did a lot of Googling but found nothing relevant; I tried
  reinstalling TPTP and various versions of the Agent Controller.</p>
  
  <p>In the end the problem turned out to be that I was starting Tomcat
  with the "jpda" option, which catalina.bat translates into</p>
  
  <pre><code>-Xdebug -Xrunjdwp:transport=.....
  </code></pre>
  
  <p>Removing the "jpda" command argument caused JVMTI to start working.  </p>
  
  <p>SO, the question is: I found nothing during any of my searches to
  indicate that a JVMTI agent is incompatible with debugging.  Can
  someone explain what is going on and why JVMTI + JDWP is not a valid
  setup?</p>