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 /*

  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code 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

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #ifndef SHARE_VM_SERVICES_ATTACHLISTENER_HPP

 #define SHARE_VM_SERVICES_ATTACHLISTENER_HPP

 #include "memory/allocation.hpp"

 #include "utilities/debug.hpp"

 #include "utilities/ostream.hpp"

 // The AttachListener thread services a queue of operations that are enqueued

 // by client tools. Each operation is identified by a name and has up to 3

 // arguments. The operation name is mapped to a function which performs the

 // operation. The function is called with an outputStream which is can use to

 // write any result data (for examples the properties command serializes

 // properties names and values to the output stream). When the function

 // complets the result value and any result data is returned to the client

 // tool.

 #ifndef SERVICES_KERNEL

 class AttachOperation;

 typedef jint (*AttachOperationFunction)(AttachOperation* op, outputStream* out);

 struct AttachOperationFunctionInfo {

   const char* name;

   AttachOperationFunction func;

 };

 #endif // SERVICES_KERNEL

 class AttachListener: AllStatic {

  public:

   static void init()  NOT_SERVICES_RETURN;

   static void abort() NOT_SERVICES_RETURN;

   // invoke to perform clean-up tasks when all clients detach

   static void detachall() NOT_SERVICES_RETURN;

   // indicates if the Attach Listener needs to be created at startup

   static bool init_at_startup() NOT_SERVICES_RETURN_(false);

   // indicates if we have a trigger to start the Attach Listener

   static bool is_init_trigger() NOT_SERVICES_RETURN_(false);

 #if !INCLUDE_SERVICES

   static bool is_attach_supported()             { return false; }

 #else

  private:

   static volatile bool _initialized;

  public:

   static bool is_initialized()                  { return _initialized; }

   static void set_initialized()                 { _initialized = true; }

   // indicates if this VM supports attach-on-demand

   static bool is_attach_supported()             { return !DisableAttachMechanism; }

   // platform specific initialization

   static int pd_init();

   // platform specific operation

   static AttachOperationFunctionInfo* pd_find_operation(const char* name);

   // platform specific flag change

   static jint pd_set_flag(AttachOperation* op, outputStream* out);

   // platform specific detachall

   static void pd_detachall();

   // platform specific data dump

   static void pd_data_dump();

   // dequeue the next operation

   static AttachOperation* dequeue();

 #endif // !INCLUDE_SERVICES

 };

 #if INCLUDE_SERVICES

 class AttachOperation: public CHeapObj<mtInternal> {

  public:

   enum {

     name_length_max = 16,       // maximum length of  name

     arg_length_max = 1024,      // maximum length of argument

     arg_count_max = 3           // maximum number of arguments

   };

   // name of special operation that can be enqueued when all

   // clients detach

   static char* detachall_operation_name() { return (char*)"detachall"; }

  private:

   char _name[name_length_max+1];

   char _arg[arg_count_max][arg_length_max+1];

  public:

   const char* name() const                      { return _name; }

   // set the operation name

   void set_name(char* name) {

     assert(strlen(name) <= name_length_max, "exceeds maximum name length");

     strcpy(_name, name);

   }

   // get an argument value

   const char* arg(int i) const {

     assert(i>=0 && i<arg_count_max, "invalid argument index");

     return _arg[i];

   }

   // set an argument value

   void set_arg(int i, char* arg) {

     assert(i>=0 && i<arg_count_max, "invalid argument index");

     if (arg == NULL) {

       _arg[i][0] = '\0';

     } else {

       assert(strlen(arg) <= arg_length_max, "exceeds maximum argument length");

       strcpy(_arg[i], arg);

     }

   }

   // create an operation of a given name

   AttachOperation(char* name) {

     set_name(name);

     for (int i=0; i<arg_count_max; i++) {

       set_arg(i, NULL);

     }

   }

   // complete operation by sending result code and any result data to the client

   virtual void complete(jint result, bufferedStream* result_stream) = 0;

 };

 #endif // INCLUDE_SERVICES

 #endif // SHARE_VM_SERVICES_ATTACHLISTENER_HPP