Mercurial > hg > truffle
view src/share/vm/services/diagnosticFramework.hpp @ 18719:6484e5c068c7
Generalize object reading in HotSpotMemoryAccessProvider.
author | Roland Schatz <roland.schatz@oracle.com> |
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date | Thu, 18 Dec 2014 15:31:12 +0100 |
parents | 31a4e55f8c9d |
children |
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/* * Copyright (c) 2011, 2013, 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_DIAGNOSTICFRAMEWORK_HPP #define SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP #include "classfile/vmSymbols.hpp" #include "memory/allocation.hpp" #include "runtime/arguments.hpp" #include "runtime/os.hpp" #include "runtime/vm_version.hpp" #include "runtime/vmThread.hpp" #include "utilities/ostream.hpp" enum DCmdSource { DCmd_Source_Internal = 0x01U, // invocation from the JVM DCmd_Source_AttachAPI = 0x02U, // invocation via the attachAPI DCmd_Source_MBean = 0x04U // invocation via a MBean }; // Warning: strings referenced by the JavaPermission struct are passed to // the native part of the JDK. Avoid use of dynamically allocated strings // that could be de-allocated before the JDK native code had time to // convert them into Java Strings. struct JavaPermission { const char* _class; const char* _name; const char* _action; }; // CmdLine is the class used to handle a command line containing a single // diagnostic command and its arguments. It provides methods to access the // command name and the beginning of the arguments. The class is also // able to identify commented command lines and the "stop" keyword class CmdLine : public StackObj { private: const char* _cmd; size_t _cmd_len; const char* _args; size_t _args_len; public: CmdLine(const char* line, size_t len, bool no_command_name); const char* args_addr() const { return _args; } size_t args_len() const { return _args_len; } const char* cmd_addr() const { return _cmd; } size_t cmd_len() const { return _cmd_len; } bool is_empty() { return _cmd_len == 0; } bool is_executable() { return is_empty() || _cmd[0] != '#'; } bool is_stop() { return !is_empty() && strncmp("stop", _cmd, _cmd_len) == 0; } }; // Iterator class taking a character string in input and returning a CmdLine // instance for each command line. The argument delimiter has to be specified. class DCmdIter : public StackObj { friend class DCmd; private: const char* _str; char _delim; size_t _len; size_t _cursor; public: DCmdIter(const char* str, char delim) { _str = str; _delim = delim; _len = strlen(str); _cursor = 0; } bool has_next() { return _cursor < _len; } CmdLine next() { assert(_cursor <= _len, "Cannot iterate more"); size_t n = _cursor; while (n < _len && _str[n] != _delim) n++; CmdLine line(&(_str[_cursor]), n - _cursor, false); _cursor = n + 1; // The default copy constructor of CmdLine is used to return a CmdLine // instance to the caller. return line; } }; // Iterator class to iterate over diagnostic command arguments class DCmdArgIter : public ResourceObj { const char* _buffer; size_t _len; size_t _cursor; const char* _key_addr; size_t _key_len; const char* _value_addr; size_t _value_len; char _delim; public: DCmdArgIter(const char* buf, size_t len, char delim) { _buffer = buf; _len = len; _delim = delim; _cursor = 0; } bool next(TRAPS); const char* key_addr() { return _key_addr; } size_t key_length() { return _key_len; } const char* value_addr() { return _value_addr; } size_t value_length() { return _value_len; } }; // A DCmdInfo instance provides a description of a diagnostic command. It is // used to export the description to the JMX interface of the framework. class DCmdInfo : public ResourceObj { protected: const char* _name; /* Name of the diagnostic command */ const char* _description; /* Short description */ const char* _impact; /* Impact on the JVM */ JavaPermission _permission; /* Java Permission required to execute this command if any */ int _num_arguments; /* Number of supported options or arguments */ bool _is_enabled; /* True if the diagnostic command can be invoked, false otherwise */ public: DCmdInfo(const char* name, const char* description, const char* impact, JavaPermission permission, int num_arguments, bool enabled) { this->_name = name; this->_description = description; this->_impact = impact; this->_permission = permission; this->_num_arguments = num_arguments; this->_is_enabled = enabled; } const char* name() const { return _name; } const char* description() const { return _description; } const char* impact() const { return _impact; } JavaPermission permission() const { return _permission; } int num_arguments() const { return _num_arguments; } bool is_enabled() const { return _is_enabled; } static bool by_name(void* name, DCmdInfo* info); }; // A DCmdArgumentInfo instance provides a description of a diagnostic command // argument. It is used to export the description to the JMX interface of the // framework. class DCmdArgumentInfo : public ResourceObj { protected: const char* _name; /* Option/Argument name*/ const char* _description; /* Short description */ const char* _type; /* Type: STRING, BOOLEAN, etc. */ const char* _default_string; /* Default value in a parsable string */ bool _mandatory; /* True if the option/argument is mandatory */ bool _option; /* True if it is an option, false if it is an argument */ /* (see diagnosticFramework.hpp for option/argument definitions) */ bool _multiple; /* True is the option can be specified several time */ int _position; /* Expected position for this argument (this field is */ /* meaningless for options) */ public: DCmdArgumentInfo(const char* name, const char* description, const char* type, const char* default_string, bool mandatory, bool option, bool multiple) { this->_name = name; this->_description = description; this->_type = type; this->_default_string = default_string; this->_option = option; this->_mandatory = mandatory; this->_option = option; this->_multiple = multiple; this->_position = -1; } DCmdArgumentInfo(const char* name, const char* description, const char* type, const char* default_string, bool mandatory, bool option, bool multiple, int position) { this->_name = name; this->_description = description; this->_type = type; this->_default_string = default_string; this->_option = option; this->_mandatory = mandatory; this->_option = option; this->_multiple = multiple; this->_position = position; } const char* name() const { return _name; } const char* description() const { return _description; } const char* type() const { return _type; } const char* default_string() const { return _default_string; } bool is_mandatory() const { return _mandatory; } bool is_option() const { return _option; } bool is_multiple() const { return _multiple; } int position() const { return _position; } }; // The DCmdParser class can be used to create an argument parser for a // diagnostic command. It is not mandatory to use it to parse arguments. // The DCmdParser parses a CmdLine instance according to the parameters that // have been declared by its associated diagnostic command. A parameter can // either be an option or an argument. Options are identified by the option name // while arguments are identified by their position in the command line. The // position of an argument is defined relative to all arguments passed on the // command line, options are not considered when defining an argument position. // The generic syntax of a diagnostic command is: // // <command name> [<option>=<value>] [<argument_value>] // // Example: // // command_name option1=value1 option2=value argumentA argumentB argumentC // // In this command line, the diagnostic command receives five parameters, two // options named option1 and option2, and three arguments. argumentA's position // is 0, argumentB's position is 1 and argumentC's position is 2. class DCmdParser { private: GenDCmdArgument* _options; GenDCmdArgument* _arguments_list; char _delim; public: DCmdParser() { _options = NULL; _arguments_list = NULL; _delim = ' '; } void add_dcmd_option(GenDCmdArgument* arg); void add_dcmd_argument(GenDCmdArgument* arg); GenDCmdArgument* lookup_dcmd_option(const char* name, size_t len); GenDCmdArgument* arguments_list() { return _arguments_list; }; void check(TRAPS); void parse(CmdLine* line, char delim, TRAPS); void print_help(outputStream* out, const char* cmd_name); void reset(TRAPS); void cleanup(); int num_arguments(); GrowableArray<const char*>* argument_name_array(); GrowableArray<DCmdArgumentInfo*>* argument_info_array(); }; // The DCmd class is the parent class of all diagnostic commands // Diagnostic command instances should not be instantiated directly but // created using the associated factory. The factory can be retrieved with // the DCmdFactory::getFactory() method. // A diagnostic command instance can either be allocated in the resource Area // or in the C-heap. Allocation in the resource area is recommended when the // current thread is the only one which will access the diagnostic command // instance. Allocation in the C-heap is required when the diagnostic command // is accessed by several threads (for instance to perform asynchronous // execution). // To ensure a proper cleanup, it's highly recommended to use a DCmdMark for // each diagnostic command instance. In case of a C-heap allocated diagnostic // command instance, the DCmdMark must be created in the context of the last // thread that will access the instance. class DCmd : public ResourceObj { protected: outputStream* _output; bool _is_heap_allocated; public: DCmd(outputStream* output, bool heap_allocated) { _output = output; _is_heap_allocated = heap_allocated; } static const char* name() { return "No Name";} static const char* description() { return "No Help";} static const char* disabled_message() { return "Diagnostic command currently disabled"; } // The impact() method returns a description of the intrusiveness of the diagnostic // command on the Java Virtual Machine behavior. The rational for this method is that some // diagnostic commands can seriously disrupt the behavior of the Java Virtual Machine // (for instance a Thread Dump for an application with several tens of thousands of threads, // or a Head Dump with a 40GB+ heap size) and other diagnostic commands have no serious // impact on the JVM (for instance, getting the command line arguments or the JVM version). // The recommended format for the description is <impact level>: [longer description], // where the impact level is selected among this list: {Low, Medium, High}. The optional // longer description can provide more specific details like the fact that Thread Dump // impact depends on the heap size. static const char* impact() { return "Low: No impact"; } // The permission() method returns the description of Java Permission. This // permission is required when the diagnostic command is invoked via the // DiagnosticCommandMBean. The rationale for this permission check is that // the DiagnosticCommandMBean can be used to perform remote invocations of // diagnostic commands through the PlatformMBeanServer. The (optional) Java // Permission associated with each diagnostic command should ease the work // of system administrators to write policy files granting permissions to // execute diagnostic commands to remote users. Any diagnostic command with // a potential impact on security should overwrite this method. static const JavaPermission permission() { JavaPermission p = {NULL, NULL, NULL}; return p; } static int num_arguments() { return 0; } outputStream* output() { return _output; } bool is_heap_allocated() { return _is_heap_allocated; } virtual void print_help(const char* name) { output()->print_cr("Syntax: %s", name); } virtual void parse(CmdLine* line, char delim, TRAPS) { DCmdArgIter iter(line->args_addr(), line->args_len(), delim); bool has_arg = iter.next(CHECK); if (has_arg) { THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "The argument list of this diagnostic command should be empty."); } } virtual void execute(DCmdSource source, TRAPS) { } virtual void reset(TRAPS) { } virtual void cleanup() { } // support for the JMX interface virtual GrowableArray<const char*>* argument_name_array() { GrowableArray<const char*>* array = new GrowableArray<const char*>(0); return array; } virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array() { GrowableArray<DCmdArgumentInfo*>* array = new GrowableArray<DCmdArgumentInfo*>(0); return array; } // main method to invoke the framework static void parse_and_execute(DCmdSource source, outputStream* out, const char* cmdline, char delim, TRAPS); }; class DCmdWithParser : public DCmd { protected: DCmdParser _dcmdparser; public: DCmdWithParser (outputStream *output, bool heap=false) : DCmd(output, heap) { } static const char* name() { return "No Name";} static const char* description() { return "No Help";} static const char* disabled_message() { return "Diagnostic command currently disabled"; } static const char* impact() { return "Low: No impact"; } static const JavaPermission permission() {JavaPermission p = {NULL, NULL, NULL}; return p; } static int num_arguments() { return 0; } virtual void parse(CmdLine *line, char delim, TRAPS); virtual void execute(DCmdSource source, TRAPS) { } virtual void reset(TRAPS); virtual void cleanup(); virtual void print_help(const char* name); virtual GrowableArray<const char*>* argument_name_array(); virtual GrowableArray<DCmdArgumentInfo*>* argument_info_array(); }; class DCmdMark : public StackObj { DCmd* _ref; public: DCmdMark(DCmd* cmd) { _ref = cmd; } ~DCmdMark() { if (_ref != NULL) { _ref->cleanup(); if (_ref->is_heap_allocated()) { delete _ref; } } } }; // Diagnostic commands are not directly instantiated but created with a factory. // Each diagnostic command class has its own factory. The DCmdFactory class also // manages the status of the diagnostic command (hidden, enabled). A DCmdFactory // has to be registered to make the diagnostic command available (see // management.cpp) class DCmdFactory: public CHeapObj<mtInternal> { private: static Mutex* _dcmdFactory_lock; static bool _send_jmx_notification; static bool _has_pending_jmx_notification; // Pointer to the next factory in the singly-linked list of registered // diagnostic commands DCmdFactory* _next; // When disabled, a diagnostic command cannot be executed. Any attempt to // execute it will result in the printing of the disabled message without // instantiating the command. bool _enabled; // When hidden, a diagnostic command doesn't appear in the list of commands // provided by the 'help' command. bool _hidden; uint32_t _export_flags; int _num_arguments; static DCmdFactory* _DCmdFactoryList; public: DCmdFactory(int num_arguments, uint32_t flags, bool enabled, bool hidden) { _next = NULL; _enabled = enabled; _hidden = hidden; _export_flags = flags; _num_arguments = num_arguments; } bool is_enabled() const { return _enabled; } void set_enabled(bool b) { _enabled = b; } bool is_hidden() const { return _hidden; } void set_hidden(bool b) { _hidden = b; } uint32_t export_flags() { return _export_flags; } void set_export_flags(uint32_t f) { _export_flags = f; } int num_arguments() { return _num_arguments; } DCmdFactory* next() { return _next; } virtual DCmd* create_Cheap_instance(outputStream* output) = 0; virtual DCmd* create_resource_instance(outputStream* output) = 0; virtual const char* name() const = 0; virtual const char* description() const = 0; virtual const char* impact() const = 0; virtual const JavaPermission permission() const = 0; virtual const char* disabled_message() const = 0; // Register a DCmdFactory to make a diagnostic command available. // Once registered, a diagnostic command must not be unregistered. // To prevent a diagnostic command from being executed, just set the // enabled flag to false. static int register_DCmdFactory(DCmdFactory* factory); static DCmdFactory* factory(DCmdSource source, const char* cmd, size_t len); // Returns a C-heap allocated diagnostic command for the given command line static DCmd* create_global_DCmd(DCmdSource source, CmdLine &line, outputStream* out, TRAPS); // Returns a resourceArea allocated diagnostic command for the given command line static DCmd* create_local_DCmd(DCmdSource source, CmdLine &line, outputStream* out, TRAPS); static GrowableArray<const char*>* DCmd_list(DCmdSource source); static GrowableArray<DCmdInfo*>* DCmdInfo_list(DCmdSource source); static void set_jmx_notification_enabled(bool enabled) { _send_jmx_notification = enabled; } static void push_jmx_notification_request(); static bool has_pending_jmx_notification() { return _has_pending_jmx_notification; } static void send_notification(TRAPS); private: static void send_notification_internal(TRAPS); friend class HelpDCmd; }; // Template to easily create DCmdFactory instances. See management.cpp // where this template is used to create and register factories. template <class DCmdClass> class DCmdFactoryImpl : public DCmdFactory { public: DCmdFactoryImpl(uint32_t flags, bool enabled, bool hidden) : DCmdFactory(DCmdClass::num_arguments(), flags, enabled, hidden) { } // Returns a C-heap allocated instance virtual DCmd* create_Cheap_instance(outputStream* output) { return new (ResourceObj::C_HEAP, mtInternal) DCmdClass(output, true); } // Returns a resourceArea allocated instance virtual DCmd* create_resource_instance(outputStream* output) { return new DCmdClass(output, false); } virtual const char* name() const { return DCmdClass::name(); } virtual const char* description() const { return DCmdClass::description(); } virtual const char* impact() const { return DCmdClass::impact(); } virtual const JavaPermission permission() const { return DCmdClass::permission(); } virtual const char* disabled_message() const { return DCmdClass::disabled_message(); } }; // This class provides a convenient way to register Dcmds, without a need to change // management.cpp every time. Body of these two methods resides in // diagnosticCommand.cpp class DCmdRegistrant : public AllStatic { private: static void register_dcmds(); static void register_dcmds_ext(); friend class Management; }; #endif // SHARE_VM_SERVICES_DIAGNOSTICFRAMEWORK_HPP