1 /*
   2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jfr/dcmd/jfrDcmds.hpp"
  27 #include "jfr/jfrEvents.hpp"
  28 #include "jfr/periodic/jfrThreadDumpEvent.hpp"
  29 #include "utilities/exceptions.hpp"
  30 #include "utilities/ostream.hpp"
  31 
  32 /**
  33 *  Worker impl for generating and writing dcmd commands
  34 *  as jfr events.
  35 *  dispatch to diagnosticcommands "parse_and_execute"
  36 *
  37 *  param: cmd = the DCMD to execute (including options)
  38 */
  39 static bool execute_dcmd(bufferedStream& st, const char* const cmd) {
  40   Thread* THREAD = Thread::current();
  41   assert(!HAS_PENDING_EXCEPTION, "dcmd does not expect pending exceptions on entry!");
  42   // delegate to DCmd execution
  43   DCmd::parse_and_execute(DCmd_Source_Internal, &st, cmd, ' ', THREAD);
  44   if (HAS_PENDING_EXCEPTION) {
  45     if (LogJFR) tty->print_cr("unable to create jfr event for DCMD %s", cmd);
  46     if (LogJFR) tty->print_cr("exception type: %s", PENDING_EXCEPTION->klass()->external_name());
  47     // don't unwind this exception
  48     CLEAR_PENDING_EXCEPTION;
  49     // if exception occurred,
  50     // reset stream.
  51     st.reset();
  52     return false;
  53   }
  54   return true;
  55 }
  56 
  57 // caller needs ResourceMark
  58 const char* JfrDcmdEvent::thread_dump() {
  59   assert(EventThreadDump::is_enabled(), "invariant");
  60   bufferedStream st;
  61   execute_dcmd(st, "Thread.print");
  62   return st.as_string();
  63 }