WWW-www.enlightenment.org pushed a commit to branch master. http://git.enlightenment.org/website/www-content.git/commit/?id=49ee869a22fc2914ac94e344e9b98c6e70d3fe8f
commit 49ee869a22fc2914ac94e344e9b98c6e70d3fe8f Author: Gareth Halfacree <[email protected]> Date: Mon Dec 11 06:57:36 2017 -0800 Wiki page log-levels.md changed with summary [] by Gareth Halfacree --- pages/develop/debug/log-levels.md.txt | 115 ++++------------------------------ 1 file changed, 12 insertions(+), 103 deletions(-) diff --git a/pages/develop/debug/log-levels.md.txt b/pages/develop/debug/log-levels.md.txt index 1a16a6014..01d2f6555 100644 --- a/pages/develop/debug/log-levels.md.txt +++ b/pages/develop/debug/log-levels.md.txt @@ -1,8 +1,8 @@ --- -~~Title: Log Levels~~ +~~Title: Error Logging~~ --- -# Log Levels # +# Error Logging # EFL uses a common method to log error messages, called ``Eina_Log``, which allows you to adjust the verbosity of the logs using environment variables. @@ -68,109 +68,18 @@ EINA_LOG_LEVEL={N} EINA_LOG_LEVELS_GLOB=eina_*:0 ./{application} Removing these internal logs from the output makes it easier for you to see your own domain messages. -## Eina_Log_Print() ## +### Aborting on Selected Log Level ## -``Eina`` provides ``eina_log_print()``, a standard function to manage all logging messages. This function may be called directly or using helper macros including ``EINA_LOG_DBG()``, ``EINA_LOG_ERR()`` or those that take a specific domain as an argument as with ``EINA_LOG_DOM_DBG()`` and ``EINA_LOG_DOM_ERR()``. Internally, ``eina_log_print()`` will call the function defined with ``eina_log_print_cb_set()``, which defaults to ``eina_log_print_cb_stderr()`` but may be changed to do whatever [...] +As well as controlling the logs themselves, the respective log levels can be used to close a program - calling ``abort()`` - once a message of a given level is logged, allowing you to automatically terminate execution. This is toggled through the environment variable ``EINA_LOG_ABORT``, while the level to be considered critical - and thus terminate execution - through the environment variable ``EINA_LOG_ABORT_LEVEL``. -The logging system is thread-safe once initialized with ``eina_log_threads_enable()``. The thread that calls this function first is considered "main thread" and other threads will have their thread id (``pthread_self()``) printed in the log message so it is easy to detect from where the messages are coming. +> **NOTE:** +> Aborting at a particular log level can also be controlled from within the application itself using the ``eina_log_abort_on_critical_set()`` and ``eina_log_abort_on_critical_level_set()`` functions. -The different logging levels serve to customize the amount of debugging information and may be used to automatically call ``abort()`` once a message of a given level is printed. This is controlled by the environment variable ``EINA_LOG_ABORT`` and the level to be considered critical with ``EINA_LOG_ABORT_LEVEL``. These can be changed with ``eina_log_abort_on_critical_set()`` and ``eina_log_abort_on_critical_level_set()``. - -The default maximum level to print is defined by the environment variable ``EINA_LOG_LEVEL`` but may be set per-domain with ``EINA_LOG_LEVELS``. It will default to ``EINA_LOG_ERR``. This can be changed with ``eina_log_level_set()``. - -To use the log system ``Eina`` must be initialized with ``eina_init()`` and later shut down with ``eina_shutdown()``. - -### Controlling Print Callbacks ### - -The log module allows the user to change the way ``eina_log_print()`` displays messages. It suffices to pass to ``eina_log_print_cb_set()`` the function used to display the message. That function must be of type ``#Eina_Log_Print_Cb``. As custom data can be passed to that callback, customized messages can be displayed. - -It is suggested to not use ``__FILE__``, ``__FUNCTION__`` or ``__LINE__`` when writing that callback, but when defining macros like ``EINA_LOG_ERR()`` and others. - -## Logging from an Application ## - -The following example, available for download from the [Enlightenment Project git repository](https://git.enlightenment.org/tools/examples.git/tree/reference/c/eina/src/eina_log.c), demonstrates the control of logging from within an application. - -```c -#define EFL_EO_API_SUPPORT 1 -#define EFL_BETA_API_SUPPORT 1 - -#include <stdio.h> - -#include <Eina.h> -#include <Efl_Core.h> - -/* - * Efl Core Log examples. - * - * This demo shows how to log at various levels and to change what log is shown. - * You can also use a custom log printer in your app as shown in _log_custom. - */ - -static double -_divide(int num, int denom) -{ - if (denom == 0) - EINA_LOG_CRIT("Attempt to divide by 0\n"); - else - { - if (denom < 0) - EINA_LOG_WARN("Possible undesirable effect, divide by negative number"); - - double ret = ((double) num / denom); - EINA_LOG_INFO("%d / %d = %f\n", num, denom, ret); - return ret; - } - - return -1; -} - -static void -_divides() -{ - _divide(5, 1); - _divide(5, -1); - _divide(5, 0); -} - -static void -_log_levels() -{ - printf("Executing with default logging\n"); - _divides(); - - eina_log_level_set(EINA_LOG_LEVEL_WARN); - printf("Executing with WARN level\n"); // same as EINA_LOG_LEVEL = 2 - _divides(); - - eina_log_level_set(EINA_LOG_LEVEL_INFO); - printf("Executing with INFO on\n"); // same as EINA_LOG_LEVEL = 3 - _divides(); -} - -void _print_cb(const Eina_Log_Domain *domain EINA_UNUSED, Eina_Log_Level level, - const char *file, const char *fnc, int line, - const char *fmt, void *data EINA_UNUSED, va_list args) -{ - fprintf(stdout, "LOG %d <%s (%s:%d)> ", level, fnc, file, line); - vfprintf(stdout, fmt, args); - putc('\n', stdout); -} +```bash +EINA_LOG_ABORT_LEVEL={N} EINA_LOG_ABORT ./{application} +``` -static void -_log_custom() -{ - printf("Executing with custom log printer\n"); - eina_log_print_cb_set(_print_cb, NULL); - _divides(); -} +## Further Reading ## -EAPI_MAIN void -efl_main(void *data EINA_UNUSED, const Efl_Event *ev EINA_UNUSED) -{ - _log_levels(); - _log_custom(); - - efl_exit(0); -} -EFL_MAIN() -``` \ No newline at end of file +[Eina Programming Guide: Logging](/develop/c/eina/logging.md) +: A reference, including example, for the Eina_Log module. \ No newline at end of file --
