nuttx/nuttx-mirror
1
2
Fork 0
mirror of https://github.com/apache/nuttx.git synced 2025-01-13 02:48:37 +08:00
Code Issues Projects Releases Packages Wiki Activity Actions

Revert "drivers/pipes: return after short write if buffer is full"

Browse source 
This reverts commit d0680fd1bc.
This commit is contained in:
Xiang Xiao 2024-11-26 17:08:49 +08:00 committed by Alan C. Assis
parent 610efc8f1a
commit 573115734d
1 changed files with 85 additions and 44 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

99
drivers/pipes/pipe_common.c
View file

@ -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);
@ -545,6 +546,11 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const char *buffer,
return ret;
}
/* Loop until all of the bytes have been written */
last = 0;
for (; ; )
{
/* 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
@ -554,41 +560,20 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const char *buffer,
if (dev->d_nreaders <= 0 && PIPE_IS_POLICY_0(dev->d_flags))
{
nxrmutex_unlock(&dev->d_bflock);
return -EPIPE;
return nwritten == 0 ? -EPIPE : nwritten;
}
/* Would the next write overflow the circular buffer? */
while (circbuf_is_full(&dev->d_buffer))
if (!circbuf_is_full(&dev->d_buffer))
{
if (filep->f_oflags & O_NONBLOCK)
/* Loop until all of the bytes have been written */
nwritten += circbuf_write(&dev->d_buffer,
buffer + nwritten, len - nwritten);
if ((size_t)nwritten == len)
{
/* If O_NONBLOCK was set, then return EGAIN. */
nxrmutex_unlock(&dev->d_bflock);
return -EAGAIN;
}
else
{
/* 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 (ssize_t)ret;
}
}
}
/* Write data to buffer. */
nwritten = circbuf_write(&dev->d_buffer, buffer, len);
/* Notify all poll/select waiters that they can read from the
* FIFO when buffer used exceeds poll threshold.
*/
@ -607,8 +592,64 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const char *buffer,
/* 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?
*/
if (last < nwritten)
{
/* Notify all poll/select waiters that they can read from the
* FIFO.
*/
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);
}
last = nwritten;
/* If O_NONBLOCK was set, then return partial bytes written or
* EGAIN.
*/
if (filep->f_oflags & O_NONBLOCK)
{
if (nwritten == 0)
{
nwritten = -EAGAIN;
}
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;
}
}
}
}
/****************************************************************************