1/*
2 * Copyright (c) 2015, 2016, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24#ifndef SHARE_VM_LOGGING_LOGCONFIGURATION_HPP
25#define SHARE_VM_LOGGING_LOGCONFIGURATION_HPP
26
27#include "logging/logLevel.hpp"
28#include "memory/allocation.hpp"
29#include "utilities/globalDefinitions.hpp"
30
31class LogOutput;
32class LogDecorators;
33class LogTagLevelExpression;
34
35// Global configuration of logging. Handles parsing and configuration of the logging framework,
36// and manages the list of configured log outputs. The actual tag and level configuration is
37// kept implicitly in the LogTagSets and their LogOutputLists. During configuration the tagsets
38// are iterated over and updated accordingly.
39class LogConfiguration : public AllStatic {
40 friend class VMError;
41 public:
42  // Function for listeners
43  typedef void (*UpdateListenerFunction)(void);
44
45  // Register callback for config change.
46  // The callback is always called with ConfigurationLock held,
47  // hence doing log reconfiguration from the callback will deadlock.
48  // The main Java thread may call this callback if there is an early registration
49  // else the attach listener JavaThread, started via diagnostic command, will be executing thread.
50  // The main purpose of this callback is to see if a loglevel have been changed.
51  // There is no way to unregister.
52  static void register_update_listener(UpdateListenerFunction cb);
53
54 private:
55  static LogOutput**  _outputs;
56  static size_t       _n_outputs;
57
58  static UpdateListenerFunction*    _listener_callbacks;
59  static size_t                     _n_listener_callbacks;
60
61  // Create a new output. Returns NULL if failed.
62  static LogOutput* new_output(const char* name, const char* options, outputStream* errstream);
63
64  // Add an output to the list of configured outputs. Returns the assigned index.
65  static size_t add_output(LogOutput* out);
66
67  // Delete a configured output. The stderr/stdout outputs can not be removed.
68  // Output should be completely disabled before it is deleted.
69  static void delete_output(size_t idx);
70
71  // Disable all logging to the specified output and then delete it (unless it is stdout/stderr).
72  static void disable_output(size_t idx);
73
74  // Get output index by name. Returns SIZE_MAX if output not found.
75  static size_t find_output(const char* name);
76
77  // Configure output (add or update existing configuration) to log on tag-level combination using specified decorators.
78  static void configure_output(size_t idx, const LogTagLevelExpression& tag_level_expression, const LogDecorators& decorators);
79
80  // This should be called after any configuration change while still holding ConfigurationLock
81  static void notify_update_listeners();
82
83  // Respectively describe the built-in and runtime dependent portions of the configuration.
84  static void describe_available(outputStream* out);
85  static void describe_current_configuration(outputStream* out);
86
87
88 public:
89  // Initialization and finalization of log configuration, to be run at vm startup and shutdown respectively.
90  static void initialize(jlong vm_start_time);
91  static void finalize();
92
93  // Perform necessary post-initialization after VM startup. Enables reconfiguration of logging.
94  static void post_initialize();
95
96  // Disable all logging, equivalent to -Xlog:disable.
97  static void disable_logging();
98
99  // Configures logging on stdout for the given tags and level combination.
100  // Intended for mappings between -XX: flags and Unified Logging configuration.
101  // If exact_match is true, only tagsets with precisely the specified tags will be configured
102  // (exact_match=false is the same as "-Xlog:<tags>*=<level>", and exact_match=true is "-Xlog:<tags>=<level>").
103  // Tags should be specified using the LOG_TAGS macro, e.g.
104  // LogConfiguration::configure_stdout(LogLevel::<level>, <true/false>, LOG_TAGS(<tags>));
105  static void configure_stdout(LogLevelType level, bool exact_match, ...);
106
107  // Parse command line configuration. Parameter 'opts' is the string immediately following the -Xlog: argument ("gc" for -Xlog:gc).
108  static bool parse_command_line_arguments(const char* opts = "all");
109
110  // Parse separated configuration arguments (from JCmd/MBean and command line).
111  static bool parse_log_arguments(const char* outputstr,
112                                  const char* what,
113                                  const char* decoratorstr,
114                                  const char* output_options,
115                                  outputStream* errstream);
116
117  // Prints log configuration to outputStream, used by JCmd/MBean.
118  static void describe(outputStream* out);
119
120  // Prints usage help for command line log configuration.
121  static void print_command_line_help(FILE* out);
122
123  // Rotates all LogOutput
124  static void rotate_all_outputs();
125};
126
127#endif // SHARE_VM_LOGGING_LOGCONFIGURATION_HPP
128