1 /* 2 * Copyright (c) 2005, 2013, 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_SERVICES_ATTACHLISTENER_HPP 26 #define SHARE_VM_SERVICES_ATTACHLISTENER_HPP 27 28 #include "memory/allocation.hpp" 29 #include "utilities/debug.hpp" 30 #include "utilities/ostream.hpp" 31 #include "utilities/macros.hpp" 32 33 // The AttachListener thread services a queue of operations that are enqueued 34 // by client tools. Each operation is identified by a name and has up to 3 35 // arguments. The operation name is mapped to a function which performs the 36 // operation. The function is called with an outputStream which is can use to 37 // write any result data (for examples the properties command serializes 38 // properties names and values to the output stream). When the function 39 // complets the result value and any result data is returned to the client 40 // tool. 41 42 class AttachOperation; 43 44 typedef jint (*AttachOperationFunction)(AttachOperation* op, outputStream* out); 45 46 struct AttachOperationFunctionInfo { 47 const char* name; 48 AttachOperationFunction func; 49 }; 50 51 class AttachListener: AllStatic { 52 public: 53 static void vm_start() NOT_SERVICES_RETURN; 54 static void init() NOT_SERVICES_RETURN; 55 static void abort() NOT_SERVICES_RETURN; 56 57 // invoke to perform clean-up tasks when all clients detach 58 static void detachall() NOT_SERVICES_RETURN; 59 60 // indicates if the Attach Listener needs to be created at startup 61 static bool init_at_startup() NOT_SERVICES_RETURN_(false); 62 63 // indicates if we have a trigger to start the Attach Listener 64 static bool is_init_trigger() NOT_SERVICES_RETURN_(false); 65 66 #if !INCLUDE_SERVICES 67 static bool is_attach_supported() { return false; } 68 #else 69 private: 70 static volatile bool _initialized; 71 72 public: 73 static bool is_initialized() { return _initialized; } 74 static void set_initialized() { _initialized = true; } 75 76 // indicates if this VM supports attach-on-demand 77 static bool is_attach_supported() { return !DisableAttachMechanism; } 78 79 // platform specific initialization 80 static int pd_init(); 81 82 // platform specific operation 83 static AttachOperationFunctionInfo* pd_find_operation(const char* name); 84 85 // platform specific flag change 86 static jint pd_set_flag(AttachOperation* op, outputStream* out); 87 88 // platform specific detachall 89 static void pd_detachall(); 90 91 // platform specific data dump 92 static void pd_data_dump(); 93 94 // dequeue the next operation 95 static AttachOperation* dequeue(); 96 #endif // !INCLUDE_SERVICES 97 98 private: 99 static bool init_error(TRAPS); 100 }; 101 102 #if INCLUDE_SERVICES 103 class AttachOperation: public CHeapObj<mtInternal> { 104 public: 105 enum { 106 name_length_max = 16, // maximum length of name 107 arg_length_max = 1024, // maximum length of argument 108 arg_count_max = 3 // maximum number of arguments 109 }; 110 111 // name of special operation that can be enqueued when all 112 // clients detach 113 static char* detachall_operation_name() { return (char*)"detachall"; } 114 115 private: 116 char _name[name_length_max+1]; 117 char _arg[arg_count_max][arg_length_max+1]; 118 119 public: 120 const char* name() const { return _name; } 121 122 // set the operation name 123 void set_name(char* name) { 124 assert(strlen(name) <= name_length_max, "exceeds maximum name length"); 125 strcpy(_name, name); 126 } 127 128 // get an argument value 129 const char* arg(int i) const { 130 assert(i>=0 && i<arg_count_max, "invalid argument index"); 131 return _arg[i]; 132 } 133 134 // set an argument value 135 void set_arg(int i, char* arg) { 136 assert(i>=0 && i<arg_count_max, "invalid argument index"); 137 if (arg == NULL) { 138 _arg[i][0] = '\0'; 139 } else { 140 assert(strlen(arg) <= arg_length_max, "exceeds maximum argument length"); 141 strcpy(_arg[i], arg); 142 } 143 } 144 145 // create an operation of a given name 146 AttachOperation(char* name) { 147 set_name(name); 148 for (int i=0; i<arg_count_max; i++) { 149 set_arg(i, NULL); 150 } 151 } 152 153 // complete operation by sending result code and any result data to the client 154 virtual void complete(jint result, bufferedStream* result_stream) = 0; 155 }; 156 #endif // INCLUDE_SERVICES 157 158 #endif // SHARE_VM_SERVICES_ATTACHLISTENER_HPP