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Diffstat (limited to 'liblog/README')
| -rw-r--r-- | liblog/README | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/liblog/README b/liblog/README index 461dfbe..f29ac04 100644 --- a/liblog/README +++ b/liblog/README @@ -131,6 +131,33 @@ DESCRIPTION when opening the sub-log. It is recommended to open the log ANDROID_LOG_RDONLY in these cases. +ERRORS + If messages fail, a negative error code will be returned to the caller. + + The -ENOTCONN return code indicates that the logger daemon is stopped. + + The -EBADF return code indicates that the log access point can not be + opened, or the log buffer id is out of range. + + For the -EAGAIN return code, this means that the logging message was + temporarily backed-up either because of Denial Of Service (DOS) logging + pressure from some chatty application or service in the Android system, + or if too small of a value is set in /proc/sys/net/unix/max_dgram_qlen. + To aid in diagnosing the occurence of this, a binary event from liblog + will be sent to the log daemon once a new message can get through + indicating how many messages were dropped as a result. Please take + action to resolve the structural problems at the source. + + It is generally not advised for the caller to retry the -EAGAIN return + code as this will only make the problem(s) worse and cause your + application to temporarily drop to the logger daemon priority, BATCH + scheduling policy and background task cgroup. If you require a group of + messages to be passed atomically, merge them into one message with + embedded newlines to the maximum length LOGGER_ENTRY_MAX_PAYLOAD. + + Other return codes from writing operation can be returned. Since the + library retries on EINTR, -EINTR should never be returned. + SEE ALSO syslogd(8) |