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Add support for O_NONBLOCK

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@777 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2008-07-22 10:58:07 +00:00
parent 6b0ef9f1cc
commit 2296bfca96
1 changed files with 25 additions and 4 deletions
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29
drivers/fifo.c
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@ -49,6 +49,7 @@
#include <string.h>
#include <sched.h>
#include <semaphore.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>
#include <nuttx/fs.h>
@ -270,7 +271,7 @@ static ssize_t fifo_read(FAR struct file *filep, FAR char *buffer, size_t len)
struct inode *inode = filep->f_inode;
struct fifo_dev_s *dev = inode->i_private;
ssize_t nread = 0;
fifo_ndx_t ret;
int ret;
/* Some sanity checking */
#if CONFIG_DEBUG
@ -291,7 +292,16 @@ static ssize_t fifo_read(FAR struct file *filep, FAR char *buffer, size_t len)
while (dev->d_wrndx == dev->d_rdndx)
{
#warning "Support for O_NONBLOCK needed"
/* If O_NONBLOCK was set, then return EGAIN */
if (filep->f_oflags & O_NONBLOCK)
{
sem_post(&dev->d_bfsem);
return -EAGAIN;
}
/* Otherwise, wait for something to be written to the FIFO */
dev->d_nreaders++;
sched_lock();
sem_post(&dev->d_bfsem);
@ -408,17 +418,28 @@ static ssize_t fifo_write(FAR struct file *filep, FAR const char *buffer, size_t
sem_post(&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;
}
sem_post(&dev->d_bfsem);
return nwritten;
}
/* There is more to be written.. wait for data to be removed from the FIFO */
#warning "Support for O_NONBLOCK needed"
dev->d_nwriters++;
sched_lock();
sem_post(&dev->d_bfsem);
fifo_semtake(&dev->d_wrsem);
sched_unlock();
fifo_semtake(&dev->d_bfsem);
last = nwritten;
}
}
}