* write; so the output thread waits for an event object notifying
* it to _attempt_ a write, and then it sets an event in return
* when one completes.
+ *
+ * (It's terribly annoying having to spawn a subthread for each
+ * direction of each handle. Technically it isn't necessary for
+ * serial ports, since we could use overlapped I/O within the main
+ * thread and wait directly on the event objects in the OVERLAPPED
+ * structures. However, we can't use this trick for some types of
+ * file handle at all - for some reason Windows restricts use of
+ * OVERLAPPED to files which were opened with the overlapped flag -
+ * and so we must use threads for those. This being the case, it's
+ * simplest just to use threads for everything rather than trying
+ * to keep track of multiple completely separate mechanisms.)
*/
#include <assert.h>
*/
char buffer[4096]; /* the data read from the handle */
DWORD len; /* how much data that was */
- int readret; /* lets us know about read errors */
+ int readerr; /* lets us know about read errors */
/*
* Callback function called by this module when data arrives on
struct handle_input *ctx = (struct handle_input *) param;
OVERLAPPED ovl, *povl;
HANDLE oev;
- int readlen;
+ int readret, readlen;
if (ctx->flags & HANDLE_FLAG_OVERLAPPED) {
povl = &ovl;
memset(povl, 0, sizeof(OVERLAPPED));
povl->hEvent = oev;
}
- ctx->readret = ReadFile(ctx->h, ctx->buffer, readlen,
- &ctx->len, povl);
- if (povl && !ctx->readret && GetLastError() == ERROR_IO_PENDING) {
+ readret = ReadFile(ctx->h, ctx->buffer,readlen, &ctx->len, povl);
+ if (!readret)
+ ctx->readerr = GetLastError();
+ else
+ ctx->readerr = 0;
+ if (povl && !readret && ctx->readerr == ERROR_IO_PENDING) {
WaitForSingleObject(povl->hEvent, INFINITE);
- ctx->readret = GetOverlappedResult(ctx->h, povl, &ctx->len, FALSE);
+ readret = GetOverlappedResult(ctx->h, povl, &ctx->len, FALSE);
+ if (!readret)
+ ctx->readerr = GetLastError();
+ else
+ ctx->readerr = 0;
}
- if (!ctx->readret)
+ if (!readret) {
+ /*
+ * Windows apparently sends ERROR_BROKEN_PIPE when a
+ * pipe we're reading from is closed normally from the
+ * writing end. This is ludicrous; if that situation
+ * isn't a natural EOF, _nothing_ is. So if we get that
+ * particular error, we pretend it's EOF.
+ */
+ if (ctx->readerr == ERROR_BROKEN_PIPE)
+ ctx->readerr = 0;
ctx->len = 0;
+ }
- if (ctx->readret && ctx->len == 0 &&
+ if (readret && ctx->len == 0 &&
(ctx->flags & HANDLE_FLAG_IGNOREEOF))
continue;
* and read by the main thread after receiving that signal.
*/
DWORD lenwritten; /* how much data we actually wrote */
- int writeret; /* return value from WriteFile */
+ int writeerr; /* return value from WriteFile */
/*
* Data only ever read or written by the main thread.
{
struct handle_output *ctx = (struct handle_output *) param;
OVERLAPPED ovl, *povl;
+ int writeret;
if (ctx->flags & HANDLE_FLAG_OVERLAPPED)
povl = &ovl;
}
if (povl)
memset(povl, 0, sizeof(OVERLAPPED));
- ctx->writeret = WriteFile(ctx->h, ctx->buffer, ctx->len,
- &ctx->lenwritten, povl);
- if (povl && !ctx->writeret && GetLastError() == ERROR_IO_PENDING)
- ctx->writeret = GetOverlappedResult(ctx->h, povl,
- &ctx->lenwritten, TRUE);
+ writeret = WriteFile(ctx->h, ctx->buffer, ctx->len,
+ &ctx->lenwritten, povl);
+ if (!writeret)
+ ctx->writeerr = GetLastError();
+ else
+ ctx->writeerr = 0;
+ if (povl && !writeret && GetLastError() == ERROR_IO_PENDING) {
+ writeret = GetOverlappedResult(ctx->h, povl,
+ &ctx->lenwritten, TRUE);
+ if (!writeret)
+ ctx->writeerr = GetLastError();
+ else
+ ctx->writeerr = 0;
+ }
SetEvent(ctx->ev_to_main);
- if (!ctx->writeret)
+ if (!writeret)
break;
}
void *privdata, int flags)
{
struct handle *h = snew(struct handle);
+ DWORD in_threadid; /* required for Win9x */
h->output = FALSE;
h->u.i.h = handle;
add234(handles_by_evtomain, h);
CreateThread(NULL, 0, handle_input_threadfunc,
- &h->u.i, 0, NULL);
+ &h->u.i, 0, &in_threadid);
h->u.i.busy = TRUE;
return h;
void *privdata, int flags)
{
struct handle *h = snew(struct handle);
+ DWORD out_threadid; /* required for Win9x */
h->output = TRUE;
h->u.o.h = handle;
add234(handles_by_evtomain, h);
CreateThread(NULL, 0, handle_output_threadfunc,
- &h->u.i, 0, NULL);
+ &h->u.i, 0, &out_threadid);
return h;
}
/*
* EOF, or (nearly equivalently) read error.
*/
- h->u.i.gotdata(h, NULL, (h->u.i.readret ? 0 : -1));
+ h->u.i.gotdata(h, NULL, -h->u.i.readerr);
h->u.i.defunct = TRUE;
} else {
backlog = h->u.i.gotdata(h, h->u.i.buffer, h->u.i.len);
* write. Call the callback to indicate that the output
* buffer size has decreased, or to indicate an error.
*/
- if (!h->u.o.writeret) {
+ if (h->u.o.writeerr) {
/*
* Write error. Send a negative value to the callback,
* and mark the thread as defunct (because the output
* thread is terminating by now).
*/
- h->u.o.sentdata(h, -1);
+ h->u.o.sentdata(h, -h->u.o.writeerr);
h->u.o.defunct = TRUE;
} else {
bufchain_consume(&h->u.o.queued_data, h->u.o.lenwritten);