/* -*-c-*-
*
- * $Id: chan.c,v 1.1 1999/07/01 08:56:23 mdw Exp $
+ * $Id: chan.c,v 1.6 2003/10/31 13:56:14 mdw Exp $
*
* Channel management
*
- * (c) 1999 Mark Wooding
+ * (c) 1999 Straylight/Edgeware
*/
/*----- Licensing notice --------------------------------------------------*
/*----- Revision history --------------------------------------------------*
*
* $Log: chan.c,v $
- * Revision 1.1 1999/07/01 08:56:23 mdw
- * Initial revision
+ * Revision 1.6 2003/10/31 13:56:14 mdw
+ * Fix data corruption in channel\!
+ *
+ * Revision 1.5 2000/07/19 17:55:43 mdw
+ * (writechan): Pointless tweak: when the buffer is empty, reset the start
+ * pointer to the beginning. This saves doing slightly trickier
+ * @writev(2)@ calls when loading is light.
+ *
+ * Revision 1.4 1999/08/31 17:42:49 mdw
+ * Use `sel_force' to avoid a `select' call between reads and writes.
+ *
+ * Revision 1.3 1999/07/27 18:30:53 mdw
+ * Various minor portability fixes.
+ *
+ * Revision 1.2 1999/07/26 23:27:52 mdw
+ * Minor modifications for new design.
+ *
+ * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
+ * Initial revision.
*
*/
#include <unistd.h>
#include <sys/uio.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-
#include <mLib/alloc.h>
#include <mLib/conn.h>
#include <mLib/sel.h>
#include "chan.h"
#include "fw.h"
+#ifdef CHAN_DEBUG
+# define D(x) x
+#else
+# define D(x)
+#endif
+
/*----- Main code ---------------------------------------------------------*/
/* --- @writechan@ --- *
/* --- Do the write --- */
- if (base + len <= CHAN_BUFSZ)
+ D( printf("writechan %d: base = %u, len = %u; ", fd, base, len); )
+ if (base + len <= CHAN_BUFSZ) {
+ D( printf("%u:%u", base, len); )
w = write(fd, c->buf + base, len);
- else {
+ } else {
struct iovec iov[2];
iov[0].iov_base = c->buf + base;
iov[0].iov_len = CHAN_BUFSZ - base;
iov[1].iov_base = c->buf;
iov[1].iov_len = len - iov[0].iov_len;
+ D( printf("%u:%u, %u:%u",
+ base, CHAN_BUFSZ - base,
+ 0, len + base - CHAN_BUFSZ); )
w = writev(fd, iov, 2);
}
+ D( printf("; returned %d\n", w); )
/* --- Sift through the results --- */
else if (c->len == CHAN_BUFSZ && !(c->f & CHANF_CLOSE))
sel_addfile(&c->r);
c->len -= w;
+ c->base += w;
}
if (c->len == 0)
sel_rmfile(&c->w);
/* --- Close the output end if necessary --- */
- if (c->len == 0 && (c->f & CHANF_CLOSE)) {
- shutdown(fd, 1);
- c->func(c->p);
+ if (c->len == 0) {
+ c->base = 0;
+ if (c->f & CHANF_CLOSE)
+ c->func(c->p);
}
return;
{
chan *c = vp;
int r;
- unsigned base = (c->base + c->len) & (CHAN_BUFSZ - 1);
- unsigned len = CHAN_BUFSZ - c->len;
+ unsigned base = c->base;
+ unsigned len = c->len;
/* --- Do the read --- */
- if (base + len <= CHAN_BUFSZ)
- r = read(fd, c->buf + base, len);
- else {
+ D( printf("readchan %d: base = %u, len = %u; ", fd, base, len); )
+ if (base == 0) {
+ D( printf("%u:%u", len, CHAN_BUFSZ - len); )
+ r = read(fd, c->buf + len, CHAN_BUFSZ - len);
+ } else if (base + len >= CHAN_BUFSZ) {
+ D( printf("%u:%u", base + len - CHAN_BUFSZ, CHAN_BUFSZ - len); )
+ r = read(fd, c->buf + base + len - CHAN_BUFSZ, CHAN_BUFSZ - len);
+ } else {
struct iovec iov[2];
- iov[0].iov_base = c->buf + base;
- iov[0].iov_len = CHAN_BUFSZ - base;
+ iov[0].iov_base = c->buf + base + len;
+ iov[0].iov_len = CHAN_BUFSZ - base - len;
iov[1].iov_base = c->buf;
- iov[1].iov_len = len - iov[0].iov_len;
+ iov[1].iov_len = base;
+ D( printf("%u:%u, %u:%u",
+ base + len, CHAN_BUFSZ - base - len,
+ 0, base); )
r = readv(fd, iov, 2);
}
+ D( printf("; returned %d\n", r); )
/* --- Sift through the results --- */
}
else if (r == 0)
goto close;
- else if (c->len == 0 && !(c->f & CHANF_READY))
+ else if (c->len == 0 && (c->f & CHANF_READY)) {
sel_addfile(&c->w);
+ sel_force(&c->w);
+ }
c->len += r;
if (c->len == CHAN_BUFSZ)
sel_rmfile(&c->r);
close:
c->f |= CHANF_CLOSE;
- if (!c->len)
+ if (!c->len && (c->f & CHANF_READY)) {
sel_addfile(&c->w);
+ sel_force(&c->w);
+ }
sel_rmfile(&c->r);
}
if (c->f & CHANF_READY)
return;
sel_initfile(sel, &c->w, fd, SEL_WRITE, writechan, c);
- if (c->len)
+ if (c->len || (c->f & CHANF_CLOSE)) {
sel_addfile(&c->w);
+ sel_force(&c->w);
+ }
+ c->f |= CHANF_READY;
}
/* --- @chan_open@ --- *