X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/16921b2333681159fd105debe96dc147029307e6..593ae86304a79fe1420cb52505733e079a119ed3:/src/xbt/log.c diff --git a/src/xbt/log.c b/src/xbt/log.c index 6d306c05db..4b72fff99e 100644 --- a/src/xbt/log.c +++ b/src/xbt/log.c @@ -2,22 +2,333 @@ /* 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 #include +#include /* snprintf */ +#include /* snprintf */ +#include "gras_config.h" /* to get a working stdarg.h */ +#include "portable.h" /* to get a working stdarg.h */ #include "xbt_modinter.h" #include "xbt/misc.h" +#include "xbt/ex.h" #include "xbt/sysdep.h" #include "xbt/log.h" -#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 XBT_log_toc Table of contents + + - \ref log_overview + - \ref log_cat + - \ref log_pri + - \ref log_app + - \ref log_hist + - \ref log_API + - \ref log_API_cat + - \ref log_API_pri + - \ref log_API_subcat + - \ref log_API_easy + - \ref log_API_example + - \ref log_user + - \ref log_use_conf + - \ref log_use_misc + - \ref log_internals + - \ref log_in_perf + - \ref log_in_app + - \ref XBT_log_cats + +\section log_overview 1. Introduction + +This module is in charge of handling the log messages of every SimGrid +program. The main design goal are: + + - configurability: the user can choose at runtime what messages to show and + what to hide, as well as how messages get displayed. + - ease of use: both to the programmer (using preprocessor macros black magic) + and to the user (with command line options) + - performances: logging shouldn't slow down the program when turned off, for example + - deal with distributed settings: SimGrid programs are [often] distributed ones, + and the logging mecanism allows to syndicate each and every log source into the same place. + At least, its design would allow to, once we write the last missing pieces + +There is three main concepts in SimGrid's logging mecanism: 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. + +\subsection log_cat 1.1 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. In a certain sense, they can be considered as logging topics or +channels. + +\subsection log_pri 1.2 Logging priorities + +The user can naturally declare interest into this or that logging category, but +he also can specify the desired level of details for each of them. This is +controled by the priority concept (which should maybe be renamed to +severity). + +Empirically, the user can specify that he wants to see every debuging message +of GRAS while only being interested into the messages at level "error" or +higher about the XBT internals. + +\subsection log_app 1.3 Message appenders + +The message appenders are the elements in charge of actually displaying the +message to the user. For now, there is only one appender: the one able to print +stuff on stderr. But everything is in place internally to write new ones, such +as the one able to send the strings to a central server in charge of +syndicating the logs of every distributed daemons on a well known location. + +It should also be possible to pass configuration informations to the appenders, +specifying for example that the message location (file and line number) is only +relevant to debugging information, not to critical error messages. + +One day, for sure ;) + +\subsection log_hist 1.4 History of this module + +Historically, this module 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 log4c's authors. The log4c project itself was loosely based on the +Apache project's Log4J, which also inspired Log4CC, Log4py and so on. Our work +differs somehow from these projects anyway, because the C programming language +is not object oriented. + +\section log_API 2. Programmer interface + +\subsection log_API_cat 2.1 Constructing the category hierarchy + +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,desc); Create a new root + - \ref XBT_LOG_NEW_SUBCATEGORY(MyCat, ParentCat,desc); + Create a new category being child of the category ParentCat + - \ref XBT_LOG_NEW_DEFAULT_CATEGORY(MyCat,desc); + Like XBT_LOG_NEW_CATEGORY, but the new category is the default one + in this file + - \ref XBT_LOG_NEW_DEFAULT_SUBCATEGORY(MyCat, ParentCat,desc); + 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. This file is generated automatically from the SimGrid source code, so +it should be complete and accurate. + +\section log_API_pri 2.2 Declaring message 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 some 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 warning. + +CLOG5(MyCat, gras_log_priority_warning, "Values are: %d and '%s'", 5, +"oops"); + +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: + +CWARN4(MyCat, "Values are: %d and '%s'", 5, "oops"); + +\section log_API_subcat 2.3 Using a default category (the easy interface) + +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: + +WARN3("Values are: %d and '%s'", 5, "oops"); + +Only one default category can be created per file, though multiple +non-defaults can be created and used. + +\section log_API_easy 2.4 Putting all together: the easy interface + +First of all, each module should register its own category into the categories +tree using \ref XBT_LOG_NEW_DEFAULT_SUBCATEGORY. + +Then, logging should be done with the DEBUG, VERB, INFO, WARN, +ERROR or CRITICAL macro families. For each group, there is 6 different +macros (like DEBUG0, DEBUG1, DEBUG2, DEBUG3, DEBUG4 and DEBUG5), only differing +in the number of arguments passed along the format. This is because we want +SimGrid itself to keep compilable on ancient compiler not supporting variable +number of arguments to macros. But we should provide a macro simpler to use for +the users not interested in SP3 machines (FIXME). + +Under GCC, these macro check there arguments the same way than printf does. So, +if you compile with -Wall, the folliwing code will issue a warning: +DEBUG2("Found %s (id %f)", some_string, a_double) + +\section log_API_example 2.5 Example of use + +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_user 3. User interface + +\section log_use_conf 3.1 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 provided by aestheticism). You can provide several of those +arguments to change the setting of several categories, they will be applied +from left to right. So, +\verbatim --xbt-log="root.thres=debug root.thres=critical"\endverbatim +should disable any logging. + +Note that the quotes on above line are mandatory because there is a space in +the argument, so we are protecting ourselves from the shell, not from SimGrid. +We could also reach the same effect with this: +\verbatim --xbt-log=root.thres=debug --xbt-log=root.thres=critical\endverbatim + +\section log_use_misc 3.2 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. + +\section log_internals 4. Internal considerations + +This module is a mess of macro black magic, and when it goes wrong, SimGrid +studently loose its ability to explain its problems. When messing around this +module, I often find useful to define XBT_LOG_MAYDAY (which turns it back to +good old printf) for the time of finding what's going wrong. + +\section log_in_perf 4.1 Performance + +Except for the first invocation of a given category, 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. + +\todo Logging performance *may* be improved further by improving the message +propagation from appender to appender in the category tree. + +\section log_in_app 4.2 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, too. + + +*/ + + typedef struct { char *catname; e_xbt_log_priority_t thresh; @@ -27,8 +338,8 @@ static xbt_dynar_t xbt_log_settings=NULL; 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 */ } } @@ -49,20 +360,21 @@ s_xbt_log_category_t _XBT_LOGV(XBT_LOG_ROOT_CAT) = { 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) { +void xbt_log_init(int *argc,char **argv) { 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="))) { - found = 1; + 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="))) { opt=strchr(argv[i],'='); opt++; xbt_log_control_set(opt); @@ -76,9 +388,6 @@ void xbt_log_init(int *argc,char **argv, const char *defaultlog) { i--; /* compensate effect of next loop incrementation */ } } - if (!found && defaultlog) { - xbt_log_control_set(defaultlog); - } } void xbt_log_exit(void) { @@ -108,9 +417,9 @@ static void _apply_control(xbt_log_category_t cat) { xbt_log_threshold_set(cat, setting->thresh); xbt_dynar_cursor_rm(xbt_log_settings,&cursor); - if (cat->threshold <= xbt_log_priority_verbose) { + if (cat->threshold <= xbt_log_priority_debug) { s_xbt_log_event_t _log_ev = - {cat,xbt_log_priority_verbose,__FILE__,_XBT_GNUC_FUNCTION,__LINE__}; + {cat,xbt_log_priority_debug,__FILE__,_XBT_FUNCTION,__LINE__}; _xbt_log_event_log(&_log_ev, "Apply settings for category '%s': set threshold to %s (=%d)", cat->name, @@ -120,7 +429,7 @@ static void _apply_control(xbt_log_category_t cat) { } if (!found && cat->threshold <= xbt_log_priority_verbose) { s_xbt_log_event_t _log_ev = - {cat,xbt_log_priority_verbose,__FILE__,_XBT_GNUC_FUNCTION,__LINE__}; + {cat,xbt_log_priority_verbose,__FILE__,_XBT_FUNCTION,__LINE__}; _xbt_log_event_log(&_log_ev, "Category '%s': inherited threshold = %s (=%d)", cat->name, @@ -239,7 +548,7 @@ static void _xbt_log_parse_setting(const char* control_string, xbt_assert1(*dot == '.' && *eq == '=', "Invalid control string '%s'",control_string); - if (!strncmp(dot + 1, "thresh", min(eq - dot - 1,strlen("thresh")))) { + if (!strncmp(dot + 1, "thresh", min((size_t)(eq - dot - 1),strlen("thresh")))) { int i; char *neweq=xbt_strdup(eq+1); char *p=neweq-1; @@ -258,11 +567,11 @@ static void _xbt_log_parse_setting(const char* control_string, } } if (ithresh=i; + set->thresh= (e_xbt_log_priority_t) i; } 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); @@ -275,21 +584,16 @@ static void _xbt_log_parse_setting(const char* control_string, DEBUG1("This is for cat '%s'", set->catname); } -static xbt_error_t _xbt_log_cat_searchsub(xbt_log_category_t cat,char *name, - /*OUT*/xbt_log_category_t*whereto) { - xbt_error_t errcode; +static xbt_log_category_t _xbt_log_cat_searchsub(xbt_log_category_t cat,char *name) { xbt_log_category_t child; if (!strcmp(cat->name,name)) { - *whereto=cat; - return no_error; + return cat; } for(child=cat->firstChild ; child != NULL; child = child->nextSibling) { - errcode=_xbt_log_cat_searchsub(child,name,whereto); - if (errcode==no_error) - return no_error; + return _xbt_log_cat_searchsub(child,name); } - return mismatch_error; + THROW0(not_found_error,0,"No such category"); } static void _cleanup_double_spaces(char *s) { @@ -325,25 +629,26 @@ static void _cleanup_double_spaces(char *s) { } /** - * 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: * * ( [category] "." [keyword] "=" value (" ")... )... * - * where [category] is one the category names and keyword is one of the - * following: + * where [category] is one the category names (see \ref XBT_log_cats for a complete list) + * and keyword is one of the following: * - * thresh value is an integer priority level. Sets the category's - * threshold priority. + * - thres: category's threshold priority. Possible values: + * TRACE,DEBUG,VERBOSE,INFO,WARNING,ERROR,CRITICAL + * * - * @warning + * \warning * This routine may only be called once and that must be before any other * logging command! Typically, this is done from main(). + * \todo the previous warning seems a bit old and need double checking */ void xbt_log_control_set(const char* control_string) { - xbt_error_t errcode; xbt_log_setting_t set; char *cs; char *p; @@ -362,33 +667,44 @@ void xbt_log_control_set(const char* control_string) { _cleanup_double_spaces(cs); while (!done) { - xbt_log_category_t cat; + xbt_log_category_t cat=NULL; + int found=0; + xbt_ex_t e; p=strrchr(cs,' '); if (p) { *p='\0'; - *p++; + p++; } else { p=cs; done = 1; } _xbt_log_parse_setting(p,set); - - errcode = _xbt_log_cat_searchsub(&_XBT_LOGV(root),set->catname,&cat); - if (errcode == mismatch_error) { + + TRY { + cat = _xbt_log_cat_searchsub(&_XBT_LOGV(root),set->catname); + found = 1; + } CATCH(e) { + if (e.category != not_found_error) + RETHROW; + xbt_ex_free(e); + found = 0; + DEBUG0("Store for further application"); DEBUG1("push %p to the settings",(void*)set); xbt_dynar_push(xbt_log_settings,&set); /* malloc in advance the next slot */ set = xbt_new(s_xbt_log_setting_t,1); - } else { + } + + if (found) { 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) {