Non-blocking writes to a tty will block if there is a blocking write
waiting for the atomic_write semaphore.
Peter
--- linux-2.5.70/drivers/char/tty_io.c.orig 2003-06-03 21:34:42.000000000 +0100
+++ linux-2.5.70/drivers/char/tty_io.c 2003-06-04 01:40:33.000000000 +0100
@@ -687,8 +687,13 @@
{
ssize_t ret = 0, written = 0;
- if (down_interruptible(&tty->atomic_write)) {
- return -ERESTARTSYS;
+ if (file->f_flags & O_NONBLOCK) {
+ if (down_trylock(&tty->atomic_write))
+ return -EAGAIN;
+ }
+ else {
+ if (down_interruptible(&tty->atomic_write))
+ return -ERESTARTSYS;
}
if ( test_bit(TTY_NO_WRITE_SPLIT, &tty->flags) ) {
lock_kernel();
-
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This archive was generated by hypermail 2b29 : Sat Jun 07 2003 - 22:00:22 EST