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.
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 #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
31 class LogOutput;
32 class LogDecorators;
33 class 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.
39 class 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, int 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