util/log: Rename qemu_log_lock to qemu_log_trylock

This function can fail, which makes it more like ftrylockfile
or pthread_mutex_trylock than flockfile or pthread_mutex_lock,
so rename it.

To closer match the other trylock functions, release rcu_read_lock
along the failure path, so that qemu_log_unlock need not be called
on failure.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220417183019.755276-8-richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-04-17 11:29:47 -07:00
parent c59fe6e536
commit c60f599bcb
12 changed files with 18 additions and 16 deletions

View file

@ -36,15 +36,17 @@ static GArray *debug_regions;
/* Lock/unlock output. */
FILE *qemu_log_lock(void)
FILE *qemu_log_trylock(void)
{
QemuLogFile *logfile;
rcu_read_lock();
logfile = qatomic_rcu_read(&qemu_logfile);
if (logfile) {
qemu_flockfile(logfile->fd);
return logfile->fd;
} else {
rcu_read_unlock();
return NULL;
}
}
@ -53,8 +55,8 @@ void qemu_log_unlock(FILE *fd)
{
if (fd) {
qemu_funlockfile(fd);
rcu_read_unlock();
}
rcu_read_unlock();
}
/* Return the number of characters emitted. */