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Re: [Fwd: I/O errors - confusion]
On Tue, 2003-03-18 at 11:44, Nick Garnett wrote:
> Gary Thomas <gary at mlbassoc dot com> writes:
>
> >
> > I agree - either there is data or not and the return code should
> > be very clear: EAGAIN means there is none, anything else means
> > there was. I think that the code in serial.c you quote should
> > return no error when there is data.
>
> That is exactly my interpretation of what should happen. The only real
> question is whether we should make that change, or just fix it in the
> fileio code. I would vote for the former, since it results in code
> being removed, but we have to be sure we are not breaking anything
> else by doing it.
I think that this patch fixes it [correctly]:
Index: io/serial/current/src/common/serial.c
===================================================================
RCS file: /misc/cvsfiles/ecos/packages/io/serial/current/src/common/serial.c,v
retrieving revision 1.17
diff -u -5 -p -r1.17 serial.c
--- io/serial/current/src/common/serial.c 23 May 2002 23:06:27 -0000 1.17
+++ io/serial/current/src/common/serial.c 18 Mar 2003 23:37:03 -0000
@@ -341,11 +341,11 @@ serial_write(cyg_io_handle_t handle, con
#ifdef CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
// Optionally return if configured for non-blocking mode.
if (!cbuf->blocking) {
*len -= size; // number of characters actually sent
cbuf->waiting = false;
- res = -EAGAIN;
+ res = size == 0 ? -EAGAIN : ENOERROR;
break;
}
#endif // CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
cbuf->pending += size; // Have this much more to send [eventually]
if( !cyg_drv_cond_wait(&cbuf->wait) )
@@ -438,11 +438,11 @@ serial_read(cyg_io_handle_t handle, void
size++;
} else {
#ifdef CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
if (!cbuf->blocking) {
*len = size; // characters actually read
- res = -EAGAIN;
+ res = size == 0 ? -EAGAIN : ENOERROR;
break;
}
#endif // CYGOPT_IO_SERIAL_SUPPORT_NONBLOCKING
cbuf->waiting = true;
#ifdef XX_CYGDBG_DIAG_BUF
Comments?
--
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Gary Thomas |
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email: <gary at mlbassoc dot com> |
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