Pipes: Fix zero-lenth writes. From Jussi Kivilinna

This commit is contained in:
Gregory Nutt 2015-03-13 07:21:06 -06:00
parent ce0021e753
commit 0a939ff218

View File

@ -384,6 +384,11 @@ ssize_t pipecommon_read(FAR struct file *filep, FAR char *buffer, size_t len)
DEBUGASSERT(dev);
if (len == 0)
{
return 0;
}
/* Make sure that we have exclusive access to the device structure */
if (sem_wait(&dev->d_bfsem) < 0)
@ -469,6 +474,11 @@ ssize_t pipecommon_write(FAR struct file *filep, FAR const char *buffer, size_t
DEBUGASSERT(dev);
pipe_dumpbuffer("To PIPE:", (uint8_t*)buffer, len);
if (len == 0)
{
return 0;
}
/* At present, this method cannot be called from interrupt handlers. That is
* because it calls sem_wait (via pipecommon_semtake below) and sem_wait cannot
* be called from interrupt level. This actually happens fairly commonly