/* -*-c-*-
*
- * $Id: chan.c,v 1.5 2000/07/19 17:55:43 mdw Exp $
+ * $Id: chan.c,v 1.6 2003/10/31 13:56:14 mdw Exp $
*
* Channel management
*
/*----- Revision history --------------------------------------------------*
*
* $Log: chan.c,v $
+ * 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
#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);
{
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 --- */