[U-Boot] [PATCH 15/15] sandbox: Restore blocking I/O on exit

Simon Glass
2018-10-01T17:55:20Z

At present sandbox sets non-blocking I/O as soon as any input is read
from the terminal. However it does not restore the previous state on
exit. Fix this and drop the old os_read_no_block() function.

This means that we always enable blocking I/O in sandbox (if input is a
terminal) whereas previously it would only happen on the first call to
tstc() or getc(). However, the difference is likely not important.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

arch/sandbox/cpu/os.c | 23 +++++++++++++++--------
drivers/serial/sandbox.c | 2 +-
include/os.h | 10 ----------
3 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index a7f17034862..97d9b29407c 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -38,14 +38,6 @@ ssize_t os_read(int fd, void *buf, size_t count)
return read(fd, buf, count);
}

-ssize_t os_read_no_block(int fd, void *buf, size_t count)
-{
- const int flags = fcntl(fd, F_GETFL, 0);
-
- fcntl(fd, F_SETFL, flags | O_NONBLOCK);
- return os_read(fd, buf, count);
-}
-
ssize_t os_write(int fd, const void *buf, size_t count)
{
return write(fd, buf, count);
@@ -129,11 +121,18 @@ int os_write_file(const char *name, const void *buf, int size)
/* Restore tty state when we exit */
static struct termios orig_term;
static bool term_setup;
+static bool term_nonblock;

void os_fd_restore(void)
{
if (term_setup) {
+ int flags;
+
tcsetattr(0, TCSANOW, &orig_term);
+ if (term_nonblock) {
+ flags = fcntl(0, F_GETFL, 0);
+ fcntl(0, F_SETFL, flags & ~O_NONBLOCK);
+ }
term_setup = false;
}
}
@@ -142,6 +141,7 @@ void os_fd_restore(void)
void os_tty_raw(int fd, bool allow_sigs)
{
struct termios term;
+ int flags;

if (term_setup)
return;
@@ -158,6 +158,13 @@ void os_tty_raw(int fd, bool allow_sigs)
if (tcsetattr(fd, TCSANOW, &term))
return;

+ flags = fcntl(fd, F_GETFL, 0);
+ if (!(flags & O_NONBLOCK)) {
+ if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
+ return;
+ term_nonblock = true;
+ }
+
term_setup = true;
atexit(os_fd_restore);
}
diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c
index 9e9bf3e011f..4a05ea44ce9 100644
--- a/drivers/serial/sandbox.c
+++ b/drivers/serial/sandbox.c
@@ -126,7 +126,7 @@ static int sandbox_serial_pending(struct udevice *dev, bool input)
if (next_index == serial_buf_read)
return 1; /* buffer full */

- count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
+ count = os_read(0, &serial_buf[serial_buf_write], 1);
if (count == 1)
serial_buf_write = next_index;

diff --git a/include/os.h b/include/os.h
index efa9e52d124..28eb6252849 100644
--- a/include/os.h
+++ b/include/os.h
@@ -26,16 +26,6 @@ struct sandbox_state;
*/
ssize_t os_read(int fd, void *buf, size_t count);

-/**
- * Access to the OS read() system call with non-blocking access
- *
- * \param fd File descriptor as returned by os_open()
- * \param buf Buffer to place data
- * \param count Number of bytes to read
- * \return number of bytes read, or -1 on error
- */
-ssize_t os_read_no_block(int fd, void *buf, size_t count);
-
/**
* Access to the OS write() system call
*
--
2.19.0.605.g01d371f741-goog