Blocking while running a signal handler is not advisable, instead write
the log string character by character.
There is also a potential for a deadlock, as discussed in #6618
Note: querying for rtcb->sigdeliver is not 100% ideal, as it only tells
_if_ a signal handler has been queued, not if it is running. However, it
makes syslog safe / usable which is a debug feature anyhow.
support to control the opening or closing of the specified channel through the syslogmask command at runtime
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
It is used to write the log message to the channel immediately
when the log message is generated in the interrupt context, which
is faster than the normal force callback.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Found by clang-check:
syslog/syslog_write.c:96:7: warning: Value stored to 'nwritten' is never read
nwritten = g_syslog_channel->sc_write(buffer, buflen);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Ville Juven