/* log - a generic logging facility in the spirit of log4j */
-/* Copyright (c) 2004 Martin Quinson. All rights reserved. */
+/* Copyright (c) 2003, 2004 Martin Quinson. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include "xbt/error.h"
#include "xbt/dynar.h"
+/** \addtogroup XBT_log
+ *
+ * This section describes the API to the log functions used
+ * everywhere in this project.
+
+\section log_overview Overview
+
+This is an adaptation of the log4c project, which is dead upstream, and
+which I was given the permission to fork under the LGPL licence by the
+authors. log4c itself was loosely based on the Apache project's Log4J,
+Log4CC, etc. project. Because C is not object oriented, a lot had to change.
+
+There is 3 main concepts: category, priority and appender. These three
+concepts work together to enable developers to log messages according to
+message type and priority, and to control at runtime how these messages are
+formatted and where they are reported.
+
+\section log_cat Category hierarchy
+
+The first and foremost advantage of any logging API over plain printf()
+resides in its ability to disable certain log statements while allowing
+others to print unhindered. This capability assumes that the logging space,
+that is, the space of all possible logging statements, is categorized
+according to some developer-chosen criteria.
+
+This observation led to choosing category as the central concept of the
+system. Every category is declared by providing a name and an optional
+parent. If no parent is explicitly named, the root category, LOG_ROOT_CAT is
+the category's parent.
+
+A category is created by a macro call at the top level of a file. A
+category can be created with any one of the following macros:
+
+ - \ref XBT_LOG_NEW_CATEGORY(MyCat); Create a new root
+ - \ref XBT_LOG_NEW_SUBCATEGORY(MyCat, ParentCat);
+ Create a new category being child of the category ParentCat
+ - \ref XBT_LOG_NEW_DEFAULT_CATEGORY(MyCat);
+ Like XBT_LOG_NEW_CATEGORY, but the new category is the default one
+ in this file
+ - \ref XBT_LOG_NEW_DEFAULT_SUBCATEGORY(MyCat, ParentCat);
+ Like XBT_LOG_NEW_SUBCATEGORY, but the new category is the default one
+ in this file
+
+The parent cat can be defined in the same file or in another file (in
+which case you want to use the \ref XBT_LOG_EXTERNAL_CATEGORY macro to make
+it visible in the current file), but each category may have only one
+definition.
+
+Typically, there will be a Category for each module and sub-module, so you
+can independently control logging for each module.
+
+For a list of all existing categories, please refer to the \ref XBT_log_cats section.
+
+\section log_pri Priority
+
+A category may be assigned a threshold priorty. The set of priorites are
+defined by the \ref e_xbt_log_priority_t enum. All logging request under
+this priority will be discarded.
+
+If a given category is not assigned a threshold priority, then it inherits
+one from its closest ancestor with an assigned threshold. To ensure that all
+categories can eventually inherit a threshold, the root category always has
+an assigned threshold priority.
+
+Logging requests are made by invoking a logging macro on a category. All of
+the macros have a printf-style format string followed by arguments. If you
+compile with the -Wall option, gcc will warn you for unmatched arguments, ie
+when you pass a pointer to a string where an integer was specified by the
+format. This is usualy a good idea.
+
+Because most C compilers do not support vararg macros, there is a version of
+the macro for any number of arguments from 0 to 6. The macro name ends with
+the total number of arguments.
+
+Here is an example of the most basic type of macro. This is a logging
+request with priority <i>warning</i>.
+
+<code>CLOG5(MyCat, gras_log_priority_warning, "Values are: %d and '%s'", 5,
+"oops");</code>
+
+A logging request is said to be enabled if its priority is higher than or
+equal to the threshold priority of its category. Otherwise, the request is
+said to be disabled. A category without an assigned priority will inherit
+one from the hierarchy.
+
+It is possible to use any non-negative integer as a priority. If, as in the
+example, one of the standard priorites is used, then there is a convenience
+macro that is typically used instead. For example, the above example is
+equivalent to the shorter:
+
+<code>CWARN4(MyCat, "Values are: %d and '%s'", 5, "oops");</code>
+
+\subsection log_subcat Using a default category
+
+If \ref XBT_LOG_NEW_DEFAULT_SUBCATEGORY(MyCat, Parent) or
+\ref XBT_LOG_NEW_DEFAULT_CATEGORY(MyCat) is used to create the
+category, then the even shorter form can be used:
+
+<code>WARN3("Values are: %d and '%s'", 5, "oops");</code>
+
+Only one default category can be created per file, though multiple
+non-defaults can be created and used.
+
+\section log_example Example
+
+Here is a more complete example:
+
+\verbatim
+#include "xbt/log.h"
+
+/ * create a category and a default subcategory * /
+XBT_LOG_NEW_CATEGORY(VSS);
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(SA, VSS);
+
+int main() {
+ / * Now set the parent's priority. (the string would typcially be a runtime option) * /
+ xbt_log_control_set("SA.thresh=3");
+
+ / * This request is enabled, because WARNING >= INFO. * /
+ CWARN2(VSS, "Low fuel level.");
+
+ / * This request is disabled, because DEBUG < INFO. * /
+ CDEBUG2(VSS, "Starting search for nearest gas station.");
+
+ / * The default category SA inherits its priority from VSS. Thus,
+ the following request is enabled because INFO >= INFO. * /
+ INFO1("Located nearest gas station.");
+
+ / * This request is disabled, because DEBUG < INFO. * /
+ DEBUG1("Exiting gas station search");
+}
+\endverbatim
+
+\section log_conf Configuration
+Configuration is typically done during program initialization by invoking
+the xbt_log_control_set() method. The control string passed to it typically
+comes from the command line. Look at the documentation for that function for
+the format of the control string.
+
+Any SimGrid program can furthermore be configured at run time by passing a
+--xbt-log argument on the command line (--gras-log, --msg-log and
+--surf-log are synonyms). You can provide several of those arguments to
+change the setting of several categories.
+
+\section log_perf Performance
+
+Clever design insures efficiency. Except for the first invocation, a
+disabled logging request requires an a single comparison of a static
+variable to a constant.
+
+There is also compile time constant, \ref XBT_LOG_STATIC_THRESHOLD, which
+causes all logging requests with a lower priority to be optimized to 0 cost
+by the compiler. By setting it to gras_log_priority_infinite, all logging
+requests are statically disabled and cost nothing. Released executables
+might be compiled with
+\verbatim-DXBT_LOG_STATIC_THRESHOLD=gras_log_priority_infinite\endverbatim
+
+Compiling with the \verbatim-DNLOG\endverbatim option disables all logging
+requests at compilation time while the \verbatim-DNDEBUG\endverbatim disables
+the requests of priority below INFO.
+
+\section log_app Appenders
+
+Each category has an optional appender. An appender is a pointer to a
+structure which starts with a pointer to a doAppend() function. DoAppend()
+prints a message to a log.
+
+When a category is passed a message by one of the logging macros, the
+category performs the following actions:
+
+ - if the category has an appender, the message is passed to the
+ appender's doAppend() function,
+ - if 'willLogToParent' is true for the category, the message is passed
+ to the category's parent.
+
+By default, only the root category have an appender, and 'willLogToParent'
+is true for any other category. This situation causes all messages to be
+logged by the root category's appender.
+
+The default appender function currently prints to stderr, and no other one
+exist, even if more would be needed, like the one able to send the logs to a
+remote dedicated server, or other ones offering different output formats.
+This is on our TODO list for quite a while now, but your help would be
+welcome here.
+
+\section log_misc Misc and Caveats
+
+ - Do not use any of the macros that start with '_'.
+ - Log4J has a 'rolling file appender' which you can select with a run-time
+ option and specify the max file size. This would be a nice default for
+ non-kernel applications.
+ - Careful, category names are global variables.
+
+*/
+
+/*
+FAIRE DES ZOLIS LOGS
+--------------------
+Pour utiliser les logs, tu déjà faire, non ? Tu colle sur la ligne de
+commande un ou plusieurs arguments de la forme
+ --gras-log="<réglage> [<reglage>+]" (ou sans " si t'as pas d'espace)
+chaque réglage étant de la forme:
+ <canal>.thres=<priorité>
+Les différents réglages sont lus de gauche à droite.
+"root.thres=debug root.thres=critical" ferme tout, normalement.
+
+*/
+
typedef struct {
char *catname;
e_xbt_log_priority_t thresh;
static void _free_setting(void *s) {
xbt_log_setting_t set=(xbt_log_setting_t)s;
if (set) {
- xbt_free(set->catname);
-/* xbt_free(set); FIXME: uncommenting this leads to segfault when more than one chunk is passed as gras-log */
+ free(set->catname);
+/* free(set); FIXME: uncommenting this leads to segfault when more than one chunk is passed as gras-log */
}
}
NULL, 0
};
-XBT_LOG_NEW_SUBCATEGORY(gras,XBT_LOG_ROOT_CAT,"All GRAS categories");
-XBT_LOG_NEW_SUBCATEGORY(xbt,XBT_LOG_ROOT_CAT,"All XBT categories (gras toolbox)");
-XBT_LOG_NEW_SUBCATEGORY(surf,XBT_LOG_ROOT_CAT,"All SURF categories");
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(log,xbt,"Loggings from the logging mecanism itself");
+XBT_LOG_NEW_CATEGORY(xbt,"All XBT categories (simgrid toolbox)");
+XBT_LOG_NEW_CATEGORY(surf,"All SURF categories");
+XBT_LOG_NEW_CATEGORY(msg,"All MSG categories");
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(log,xbt,"Loggings from the logging mechanism itself");
void xbt_log_init(int *argc,char **argv, const char *defaultlog) {
int i,j;
char *opt;
int found=0;
- /** Set logs and init log submodule */
+ /* Set logs and init log submodule */
for (i=1; i<*argc; i++) {
- if (!strncmp(argv[i],"--gras-log=",strlen("--gras-log="))) {
+ if (!strncmp(argv[i],"--gras-log=",strlen("--gras-log=")) ||
+ !strncmp(argv[i],"--surf-log=",strlen("--surf-log=")) ||
+ !strncmp(argv[i],"--msg-log=",strlen("--msg-log=")) ||
+ !strncmp(argv[i],"--xbt-log=",strlen("--xbt-log="))) {
found = 1;
opt=strchr(argv[i],'=');
opt++;
} else {
xbt_assert1(FALSE,"Unknown priority name: %s",eq+1);
}
- xbt_free(neweq);
+ free(neweq);
} else {
char buff[512];
snprintf(buff,min(512,eq - dot - 1),"%s",dot+1);
}
/**
- * xbt_log_control_set:
- * @cs: What to parse
+ * \ingroup XBT_log
+ * \param control_string What to parse
*
* Typically passed a command-line argument. The string has the syntax:
*
* thresh value is an integer priority level. Sets the category's
* threshold priority.
*
- * @warning
+ * \warning
* This routine may only be called once and that must be before any other
* logging command! Typically, this is done from main().
*/
set = xbt_new(s_xbt_log_setting_t,1);
} else {
DEBUG0("Apply directly");
- xbt_free(set->catname);
+ free(set->catname);
xbt_log_threshold_set(cat,set->thresh);
}
}
- xbt_free(set);
- xbt_free(cs);
+ free(set);
+ free(cs);
}
void xbt_log_appender_set(xbt_log_category_t cat, xbt_log_appender_t app) {