For some reason ”getPid()” Bug Parade entry has been hanging for ever ”in progress, won’t ever fix” state.<\/p>\n
However, after quick searching there is workaround, which hopefully works in ”major” cases (meaning Linux, M$windows and OSX).<\/p>\n
NOTE: Tested logic only in Linux box. However, since logic relies into public API, it should be working in other OS also.<\/p>\n
[code lang=”java”]
\n\/**
\n * Get current process PID
\n *
\n * @return pid, -1 if resolving failed
\n *\/
\npublic static int getPID() {
\n int pid = -1;
\n try {
\n RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean();
\n String id = runtime.getName();
\n int idx = id.indexOf(’@’);
\n if (idx != -1) {
\n id = id.substring(0, idx);
\n }
\n pid = Integer.parseInt(id);
\n } catch (Exception e) {
\n LOG.warn(”Failed to resolve PID”, e);
\n }
\n return pid;
\n}
\n[\/code]<\/p>\n
So we get current process PID. Next question is what we could do with such information.<\/p>\n
And here comes one answer…<\/p>\n
We could, for example, include $JDK_HOME\/lib\/tools.jar into classpath of our application, and then perform following:<\/p>\n
[code lang=”java”]
\npublic static void dumpHeap(String pFilename) throws Exception {
\n int pid = SystemUtil.getPID();
\n String className = ”sun.tools.jmap.JMap”;
\n Class cls = Class.forName(className);
\n Class[] paramTypes = {String[].class};
\n String[] param = {
\n ”-dump:format=b,file=” + pFilename,
\n ”” + pid
\n };<\/p>\n
Method method = cls.getDeclaredMethod(”main”, pParamTypes);
\n return method.invoke(null, new Object[]{param});
\n}
\n[\/code]<\/p>\n
This piece of code creates heap dump of current java process in HPROF format. Resulting dump can be then analyzed using References<\/b>:<\/p>\njhat<\/code> utility delivered with Sun JDK 6.<\/p>\n