.. _logger_sample:
Logging
###########
Overview
********
A simple application that demonstrates use of logging subsystem. It demonstrates
main features: severity levels, timestamping, module level filtering and
instance level filtering. It also showcases logging capabilities in terms of
performance.
Building and Running
********************
This project outputs multiple log message to the console. It can be built and
executed on QEMU as follows:
.. zephyr-app-commands::
:zephyr-app: samples/subsys/logging/logger
:host-os: unix
:board: qemu_x86
:goals: run
:compact:
Sample Output
=============
.. code-block:: console
Module logging showcase.
[00:00:00.000,122] <info> foo: log in test_module 11
Disabling logging in the foo module
Function called again but with logging disabled.
Instance level logging showcase.
[00:00:00.000,274] <info> sample_instance.inst1: counter_value: 0
[00:00:00.000,274] <warn> sample_instance.inst1: Example of hexdump:
[00:00:00.000,305] <warn> sample_instance.inst1: 01 02 03 04 |....
[00:00:00.000,305] <info> sample_instance.inst2: counter_value: 0
[00:00:00.000,305] <warn> sample_instance.inst2: Example of hexdump:
[00:00:00.000,305] <warn> sample_instance.inst2: 01 02 03 04 |....
Changing filter to warning on sample_instance.inst1 instance.
[00:00:00.000,396] <warn> sample_instance.inst1: Example of hexdump:
[00:00:00.000,427] <warn> sample_instance.inst1: 01 02 03 04 |....
[00:00:00.000,427] <info> sample_instance.inst2: counter_value: 1
[00:00:00.000,427] <warn> sample_instance.inst2: Example of hexdump:
[00:00:00.000,427] <warn> sample_instance.inst2: 01 02 03 04 |....
Disabling logging on both instances.
Function call on both instances with logging disabled.
Severity levels showcase.
[00:00:00.000,610] <err> main: Error message example.
[00:00:00.000,610] <warn> main: Warning message example.
[00:00:00.000,610] <info> main: Info message example.
Logging performance showcase.
[00:00:00.134,887] <info> main: performance test - log message 0
[00:00:00.134,887] <info> main: performance test - log message 1
[00:00:00.134,887] <info> main: performance test - log message 2
[00:00:00.134,887] <info> main: performance test - log message 3
[00:00:00.134,887] <info> main: performance test - log message 4
[00:00:00.134,887] <info> main: performance test - log message 5
[00:00:00.134,887] <info> main: performance test - log message 6
[00:00:00.134,918] <info> main: performance test - log message 7
[00:00:00.134,918] <info> main: performance test - log message 8
[00:00:00.134,918] <info> main: performance test - log message 9
[00:00:00.134,918] <info> main: performance test - log message 10
[00:00:00.134,918] <info> main: performance test - log message 11
[00:00:00.134,918] <info> main: performance test - log message 12
[00:00:00.134,918] <info> main: performance test - log message 13
[00:00:00.134,948] <info> main: performance test - log message 14
Estimated logging capabilities: 245760 messages/second
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