This is an automated email from the ASF dual-hosted git repository.
acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 573115734d Revert "drivers/pipes: return after short write if buffer
is full"
573115734d is described below
commit 573115734debdfbd27453fdf4206ff92b878a055
Author: Xiang Xiao <[email protected]>
AuthorDate: Tue Nov 26 17:08:49 2024 +0800
Revert "drivers/pipes: return after short write if buffer is full"
This reverts commit d0680fd1bc51b7ead0b068fb24a31a144d22dc6c.
---
drivers/pipes/pipe_common.c | 127 +++++++++++++++++++++++++++++---------------
1 file changed, 84 insertions(+), 43 deletions(-)
diff --git a/drivers/pipes/pipe_common.c b/drivers/pipes/pipe_common.c
index f9b944c459..594c1c198b 100644
--- a/drivers/pipes/pipe_common.c
+++ b/drivers/pipes/pipe_common.c
@@ -506,6 +506,7 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const
char *buffer,
FAR struct inode *inode = filep->f_inode;
FAR struct pipe_dev_s *dev = inode->i_private;
ssize_t nwritten = 0;
+ ssize_t last;
int ret;
DEBUGASSERT(dev);
@@ -545,70 +546,110 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR
const char *buffer,
return ret;
}
- /* REVISIT: "If all file descriptors referring to the read end of a
- * pipe have been closed, then a write will cause a SIGPIPE signal to
- * be generated for the calling process. If the calling process is
- * ignoring this signal, then write(2) fails with the error EPIPE."
- */
+ /* Loop until all of the bytes have been written */
- if (dev->d_nreaders <= 0 && PIPE_IS_POLICY_0(dev->d_flags))
+ last = 0;
+ for (; ; )
{
- nxrmutex_unlock(&dev->d_bflock);
- return -EPIPE;
- }
-
- /* Would the next write overflow the circular buffer? */
+ /* REVISIT: "If all file descriptors referring to the read end of a
+ * pipe have been closed, then a write will cause a SIGPIPE signal to
+ * be generated for the calling process. If the calling process is
+ * ignoring this signal, then write(2) fails with the error EPIPE."
+ */
- while (circbuf_is_full(&dev->d_buffer))
- {
- if (filep->f_oflags & O_NONBLOCK)
+ if (dev->d_nreaders <= 0 && PIPE_IS_POLICY_0(dev->d_flags))
{
- /* If O_NONBLOCK was set, then return EGAIN. */
-
nxrmutex_unlock(&dev->d_bflock);
- return -EAGAIN;
+ return nwritten == 0 ? -EPIPE : nwritten;
}
- else
+
+ /* Would the next write overflow the circular buffer? */
+
+ if (!circbuf_is_full(&dev->d_buffer))
{
- /* Wait for data to be removed from the pipe. */
+ /* Loop until all of the bytes have been written */
- nxrmutex_unlock(&dev->d_bflock);
- ret = nxsem_wait(&dev->d_wrsem);
- if (ret < 0 || (ret = nxrmutex_lock(&dev->d_bflock)) < 0)
+ nwritten += circbuf_write(&dev->d_buffer,
+ buffer + nwritten, len - nwritten);
+
+ if ((size_t)nwritten == len)
{
- /* Either call nxsem_wait may fail because a signal was
- * received or if the task was canceled.
+ /* Notify all poll/select waiters that they can read from the
+ * FIFO when buffer used exceeds poll threshold.
*/
- return (ssize_t)ret;
+ if (circbuf_used(&dev->d_buffer) > dev->d_pollinthrd)
+ {
+ poll_notify(dev->d_fds, CONFIG_DEV_PIPE_NPOLLWAITERS,
+ POLLIN);
+ }
+
+ /* Yes.. Notify all of the waiting readers that more data is
+ * available.
+ */
+
+ pipecommon_wakeup(&dev->d_rdsem);
+
+ /* Return the number of bytes written */
+
+ nxrmutex_unlock(&dev->d_bflock);
+ return len;
}
}
- }
+ else
+ {
+ /* There is not enough room for the next byte. Was anything
+ * written in this pass?
+ */
- /* Write data to buffer. */
+ if (last < nwritten)
+ {
+ /* Notify all poll/select waiters that they can read from the
+ * FIFO.
+ */
- nwritten = circbuf_write(&dev->d_buffer, buffer, len);
+ poll_notify(dev->d_fds, CONFIG_DEV_PIPE_NPOLLWAITERS, POLLIN);
- /* Notify all poll/select waiters that they can read from the
- * FIFO when buffer used exceeds poll threshold.
- */
+ /* Yes.. Notify all of the waiting readers that more data is
+ * available.
+ */
- if (circbuf_used(&dev->d_buffer) > dev->d_pollinthrd)
- {
- poll_notify(dev->d_fds, CONFIG_DEV_PIPE_NPOLLWAITERS,
- POLLIN);
- }
+ pipecommon_wakeup(&dev->d_rdsem);
+ }
- /* Yes.. Notify all of the waiting readers that more data is
- * available.
- */
+ last = nwritten;
- pipecommon_wakeup(&dev->d_rdsem);
+ /* If O_NONBLOCK was set, then return partial bytes written or
+ * EGAIN.
+ */
- /* Return the number of bytes written */
+ if (filep->f_oflags & O_NONBLOCK)
+ {
+ if (nwritten == 0)
+ {
+ nwritten = -EAGAIN;
+ }
- nxrmutex_unlock(&dev->d_bflock);
- return nwritten;
+ nxrmutex_unlock(&dev->d_bflock);
+ return nwritten;
+ }
+
+ /* There is more to be written.. wait for data to be removed from
+ * the pipe
+ */
+
+ nxrmutex_unlock(&dev->d_bflock);
+ ret = nxsem_wait(&dev->d_wrsem);
+ if (ret < 0 || (ret = nxrmutex_lock(&dev->d_bflock)) < 0)
+ {
+ /* Either call nxsem_wait may fail because a signal was
+ * received or if the task was canceled.
+ */
+
+ return nwritten == 0 ? (ssize_t)ret : nwritten;
+ }
+ }
+ }
}
/****************************************************************************
