/*
* Interface to file system close.
*
* *pipep points to pipe control structure. When the last user releases pipe,
* it will be set to NULL.
*/
int pipe_release(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe = *pipep;
uint32_t mode;
rtems_status_code sc;
sc = rtems_semaphore_obtain(pipe->Semaphore,
RTEMS_WAIT, RTEMS_NO_TIMEOUT);
/* WARN pipe not released! */
if(sc != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred(sc);
mode = LIBIO_ACCMODE(iop);
if (mode & LIBIO_FLAGS_READ)
pipe->Readers --;
if (mode & LIBIO_FLAGS_WRITE)
pipe->Writers --;
sc = rtems_semaphore_obtain(rtems_pipe_semaphore,
RTEMS_WAIT, RTEMS_NO_TIMEOUT);
/* WARN pipe not freed and pipep not set to NULL! */
if(sc != RTEMS_SUCCESSFUL)
rtems_fatal_error_occurred(sc);
PIPE_UNLOCK(pipe);
if (pipe->Readers == 0 && pipe->Writers == 0) {
#if 0
/* To delete an anonymous pipe file when all users closed it */
if (pipe->Anonymous)
delfile = TRUE;
#endif
pipe_free(pipe);
*pipep = NULL;
}
else if (pipe->Readers == 0 && mode != LIBIO_FLAGS_WRITE)
/* Notify waiting Writers that all their partners left */
PIPE_WAKEUPWRITERS(pipe);
else if (pipe->Writers == 0 && mode != LIBIO_FLAGS_READ)
PIPE_WAKEUPREADERS(pipe);
rtems_semaphore_release(rtems_pipe_semaphore);
#if 0
if (! delfile)
return 0;
if (iop->pathinfo.ops->unlink_h == NULL)
return 0;
/* This is safe for IMFS, but how about other FSes? */
iop->flags &= ~LIBIO_FLAGS_OPEN;
if(iop->pathinfo.ops->unlink_h(&iop->pathinfo))
return -errno;
#endif
return 0;
}
/*
* Interface to file system close.
*
* *pipep points to pipe control structure. When the last user releases pipe,
* it will be set to NULL.
*/
void pipe_release(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe = *pipep;
uint32_t mode;
#if defined(RTEMS_DEBUG)
/* WARN pipe not freed and pipep not set to NULL! */
if (pipe_lock())
rtems_fatal_error_occurred(0xdeadbeef);
/* WARN pipe not released! */
if (!PIPE_LOCK(pipe))
rtems_fatal_error_occurred(0xdeadbeef);
#endif
mode = LIBIO_ACCMODE(iop);
if (mode & LIBIO_FLAGS_READ)
pipe->Readers --;
if (mode & LIBIO_FLAGS_WRITE)
pipe->Writers --;
PIPE_UNLOCK(pipe);
if (pipe->Readers == 0 && pipe->Writers == 0) {
#if 0
/* To delete an anonymous pipe file when all users closed it */
if (pipe->Anonymous)
delfile = TRUE;
#endif
pipe_free(pipe);
*pipep = NULL;
}
else if (pipe->Readers == 0 && mode != LIBIO_FLAGS_WRITE)
/* Notify waiting Writers that all their partners left */
PIPE_WAKEUPWRITERS(pipe);
else if (pipe->Writers == 0 && mode != LIBIO_FLAGS_READ)
PIPE_WAKEUPREADERS(pipe);
pipe_unlock();
#if 0
if (! delfile)
return;
if (iop->pathinfo.ops->unlink_h == NULL)
return;
/* This is safe for IMFS, but how about other FSes? */
iop->flags &= ~LIBIO_FLAGS_OPEN;
if(iop->pathinfo.ops->unlink_h(&iop->pathinfo))
return;
#endif
}
/*
* Interface to file system read.
*/
ssize_t pipe_read(
pipe_control_t *pipe,
void *buffer,
size_t count,
rtems_libio_t *iop
)
{
int chunk, chunk1, read = 0, ret = 0;
if (! PIPE_LOCK(pipe))
return -EINTR;
while (read < count) {
while (PIPE_EMPTY(pipe)) {
/* Not an error */
if (pipe->Writers == 0)
goto out_locked;
if (LIBIO_NODELAY(iop)) {
ret = -EAGAIN;
goto out_locked;
}
/* Wait until pipe is no more empty or no writer exists */
pipe->waitingReaders ++;
PIPE_UNLOCK(pipe);
if (! PIPE_READWAIT(pipe))
ret = -EINTR;
if (! PIPE_LOCK(pipe)) {
/* WARN waitingReaders not restored! */
ret = -EINTR;
goto out_nolock;
}
pipe->waitingReaders --;
if (ret != 0)
goto out_locked;
}
/* Read chunk bytes */
chunk = MIN(count - read, pipe->Length);
chunk1 = pipe->Size - pipe->Start;
if (chunk > chunk1) {
memcpy(buffer + read, pipe->Buffer + pipe->Start, chunk1);
memcpy(buffer + read + chunk1, pipe->Buffer, chunk - chunk1);
}
else
memcpy(buffer + read, pipe->Buffer + pipe->Start, chunk);
pipe->Start += chunk;
pipe->Start %= pipe->Size;
pipe->Length -= chunk;
/* For buffering optimization */
if (PIPE_EMPTY(pipe))
pipe->Start = 0;
if (pipe->waitingWriters > 0)
PIPE_WAKEUPWRITERS(pipe);
read += chunk;
}
out_locked:
PIPE_UNLOCK(pipe);
out_nolock:
if (read > 0)
return read;
return ret;
}
/*
* Interface to file system open.
*
* *pipep points to pipe control structure. If called with *pipep = NULL,
* fifo_open will try allocating and initializing a control structure. If the
* call succeeds, *pipep will be set to address of new control structure.
*/
int fifo_open(
pipe_control_t **pipep,
rtems_libio_t *iop
)
{
pipe_control_t *pipe;
unsigned int prevCounter;
int err;
err = pipe_new(pipep);
if (err)
return err;
pipe = *pipep;
switch (LIBIO_ACCMODE(iop)) {
case LIBIO_FLAGS_READ:
pipe->readerCounter ++;
if (pipe->Readers ++ == 0)
PIPE_WAKEUPWRITERS(pipe);
if (pipe->Writers == 0) {
/* Not an error */
if (LIBIO_NODELAY(iop))
break;
prevCounter = pipe->writerCounter;
err = -EINTR;
/* Wait until a writer opens the pipe */
do {
PIPE_UNLOCK(pipe);
if (! PIPE_READWAIT(pipe))
goto out_error;
if (! PIPE_LOCK(pipe))
goto out_error;
} while (prevCounter == pipe->writerCounter);
}
break;
case LIBIO_FLAGS_WRITE:
pipe->writerCounter ++;
if (pipe->Writers ++ == 0)
PIPE_WAKEUPREADERS(pipe);
if (pipe->Readers == 0 && LIBIO_NODELAY(iop)) {
PIPE_UNLOCK(pipe);
err = -ENXIO;
goto out_error;
}
if (pipe->Readers == 0) {
prevCounter = pipe->readerCounter;
err = -EINTR;
do {
PIPE_UNLOCK(pipe);
if (! PIPE_WRITEWAIT(pipe))
goto out_error;
if (! PIPE_LOCK(pipe))
goto out_error;
} while (prevCounter == pipe->readerCounter);
}
break;
case LIBIO_FLAGS_READ_WRITE:
pipe->readerCounter ++;
if (pipe->Readers ++ == 0)
PIPE_WAKEUPWRITERS(pipe);
pipe->writerCounter ++;
if (pipe->Writers ++ == 0)
PIPE_WAKEUPREADERS(pipe);
break;
}
PIPE_UNLOCK(pipe);
return 0;
out_error:
pipe_release(pipep, iop);
return err;
}
