termios: Implement non-blocking write

2 files changed, 39 insertions, 4 deletions

diff --git a/cpukit/libcsupport/src/termios.c b/cpukit/libcsupport/src/termios.c
index e59f97799c..d1058997f8 100644
--- a/cpukit/libcsupport/src/termios.c
+++ b/cpukit/libcsupport/src/termios.c
@@ -1214,9 +1214,10 @@ oproc (unsigned char c, rtems_termios_tty *tty, bool wait)
 }
 
 static uint32_t
-rtems_termios_write_tty (rtems_termios_tty *tty, const char *buf, uint32_t len)
+rtems_termios_write_tty (rtems_libio_t *iop, rtems_termios_tty *tty,
+                         const char *buf, uint32_t len)
 {
-  bool wait = true;
+  bool wait = ((iop->flags & LIBIO_FLAGS_NO_DELAY) == 0);
 
   if (tty->termios.c_oflag & OPOST) {
     uint32_t todo = len;
@@ -1252,7 +1253,8 @@ rtems_termios_write (void *arg)
     rtems_semaphore_release (tty->osem);
     return sc;
   }
-  args->bytes_moved = rtems_termios_write_tty (tty, args->buffer, args->count);
+  args->bytes_moved = rtems_termios_write_tty (args->iop, tty,
+                                               args->buffer, args->count);
   rtems_semaphore_release (tty->osem);
   return sc;
 }
@@ -2162,7 +2164,7 @@ rtems_termios_imfs_write (rtems_libio_t *iop, const void *buffer, size_t count)
     return (ssize_t) args.bytes_moved;
   }
 
-  bytes_moved = rtems_termios_write_tty (tty, buffer, count);
+  bytes_moved = rtems_termios_write_tty (iop, tty, buffer, count);
   rtems_semaphore_release (tty->osem);
   return (ssize_t) bytes_moved;
 }
diff --git a/testsuites/libtests/termios09/init.c b/testsuites/libtests/termios09/init.c
index 648d1bf7ed..f13804dcc1 100644
--- a/testsuites/libtests/termios09/init.c
+++ b/testsuites/libtests/termios09/init.c
@@ -199,6 +199,24 @@ static void input(test_context *ctx, size_t i, char c)
   }
 }
 
+static void enable_non_blocking(test_context *ctx, size_t i, bool enable)
+{
+  int flags;
+  int rv;
+
+  flags = fcntl(ctx->fds[i], F_GETFL, 0);
+  rtems_test_assert(flags >= 0);
+
+  if (enable) {
+    flags |= O_NONBLOCK;
+  } else {
+    flags &= ~O_NONBLOCK;
+  }
+
+  rv = fcntl(ctx->fds[i], F_SETFL, flags);
+  rtems_test_assert(rv == 0);
+}
+
 static void clear_set_iflag(
   test_context *ctx,
   size_t i,
@@ -968,6 +986,11 @@ static void test_write(test_context *ctx)
 
   rtems_test_assert(ctx->context_switch_counter == 0);
 
+  enable_non_blocking(ctx, i, true);
+  n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 1], 1);
+  rtems_test_assert(n == 0);
+
+  enable_non_blocking(ctx, i, false);
   n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 1], 1);
   rtems_test_assert(n == 1);
 
@@ -994,6 +1017,11 @@ static void test_write(test_context *ctx)
 
   rtems_test_assert(ctx->context_switch_counter == 2);
 
+  enable_non_blocking(ctx, i, true);
+  n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 2], 1);
+  rtems_test_assert(n == 0);
+
+  enable_non_blocking(ctx, i, false);
   n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 2], 1);
   rtems_test_assert(n == 1);
 
@@ -1020,6 +1048,11 @@ static void test_write(test_context *ctx)
 
   rtems_test_assert(ctx->context_switch_counter == 4);
 
+  enable_non_blocking(ctx, i, true);
+  n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 8], 1);
+  rtems_test_assert(n == 0);
+
+  enable_non_blocking(ctx, i, false);
   n = write(ctx->fds[i], &buf[OUTPUT_BUFFER_SIZE - 8], 1);
   rtems_test_assert(n == 1);