rev 11857 : [mq]: 8157948

   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(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
--- EOF ---