1 /*
   2  * Copyright (c) 2013, 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 #ifndef SHARE_VM_JFR_RECORDER_SERVICE_JFRPOSTBOX_HPP
  26 #define SHARE_VM_JFR_RECORDER_SERVICE_JFRPOSTBOX_HPP
  27 
  28 #include "jfr/utilities/jfrAllocation.hpp"
  29 
  30 #define MSGBIT(e) (1<<(e))
  31 
  32 enum JFR_Msg {
  33   MSG_ALL_MSGS = -1,
  34   MSG_CLONE_IN_MEMORY = 0,
  35   MSG_START,
  36   MSG_STOP,
  37   MSG_ROTATE,
  38   MSG_FULLBUFFER,
  39   MSG_CHECKPOINT,
  40   MSG_WAKEUP,
  41   MSG_SHUTDOWN,
  42   MSG_VM_ERROR,
  43   MSG_DEADBUFFER,
  44   MSG_NO_OF_MSGS
  45 };
  46 
  47 /**
  48  *  Jfr messaging.
  49  *
  50  *  Synchronous messages (posting thread waits for message completion):
  51  *
  52  *  MSG_CLONE_IN_MEMORY (0) ; MSGBIT(MSG_CLONE_IN_MEMORY) == (1 << 0) == 0x1
  53  *  MSG_START(1)            ; MSGBIT(MSG_START) == (1 << 0x1) == 0x2
  54  *  MSG_STOP (2)            ; MSGBIT(MSG_STOP) == (1 << 0x2) == 0x4
  55  *  MSG_ROTATE (3)          ; MSGBIT(MSG_ROTATE) == (1 << 0x3) == 0x8
  56  *  MSG_VM_ERROR (8)        ; MSGBIT(MSG_VM_ERROR) == (1 << 8) == 0x100
  57  *
  58  *  Asynchronous messages (posting thread returns immediately upon deposit):
  59  *
  60  *  MSG_FULLBUFFER (4)      ; MSGBIT(MSG_FULLBUFFER) == (1 << 0x4) == 0x10
  61  *  MSG_CHECKPOINT (5)      ; MSGBIT(CHECKPOINT) == (1 << 5) == 0x20
  62  *  MSG_WAKEUP (6)          ; MSGBIT(WAKEUP) == (1 << 6) == 0x40
  63  *  MSG_SHUTDOWN (7)        ; MSGBIT(MSG_SHUTDOWN) == (1 << 7) == 0x80
  64  *  MSG_DEADBUFFER (9)      ; MSGBIT(MSG_DEADBUFFER) == (1 << 9) == 0x200
  65  */
  66 
  67 class JfrPostBox : public JfrCHeapObj {
  68   friend class JfrRecorder;
  69  public:
  70   void post(JFR_Msg msg);
  71 
  72  private:
  73   uintptr_t _msg_read_serial;
  74   uintptr_t _msg_handled_serial;
  75   volatile int _messages;
  76   bool _has_waiters;
  77 
  78   JfrPostBox();
  79   static JfrPostBox& instance();
  80   static JfrPostBox* create();
  81   static void destroy();
  82 
  83   void asynchronous_post(int msg);
  84   void synchronous_post(int msg);
  85   void deposit(int new_messages);
  86   bool is_message_processed(uintptr_t serial_id) const;
  87 
  88   friend void recorderthread_entry(JavaThread*, Thread*);
  89   // for the friend declaration above
  90   bool is_empty() const;
  91   int collect();
  92   bool check_waiters(int messages) const;
  93   void notify_waiters();
  94   void notify_collection_stop();
  95 };
  96 
  97 #endif // SHARE_VM_JFR_RECORDER_SERVICE_JFRPOSTBOX_HPP