X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/bdebd7e98958c2c61b3bcaed14129e5b7d68b589..HEAD:/windows/winhandl.c diff --git a/windows/winhandl.c b/windows/winhandl.c index fc641812..286f79a6 100644 --- a/windows/winhandl.c +++ b/windows/winhandl.c @@ -16,6 +16,17 @@ * 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 @@ -85,7 +96,7 @@ struct handle_input { */ 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 @@ -101,24 +112,54 @@ static DWORD WINAPI handle_input_threadfunc(void *param) { struct handle_input *ctx = (struct handle_input *) param; OVERLAPPED ovl, *povl; + HANDLE oev; + int readret, readlen; - if (ctx->flags & HANDLE_FLAG_OVERLAPPED) + if (ctx->flags & HANDLE_FLAG_OVERLAPPED) { povl = &ovl; - else + oev = CreateEvent(NULL, TRUE, FALSE, NULL); + } else { povl = NULL; + } + + if (ctx->flags & HANDLE_FLAG_UNITBUFFER) + readlen = 1; + else + readlen = sizeof(ctx->buffer); while (1) { - if (povl) + if (povl) { memset(povl, 0, sizeof(OVERLAPPED)); - ctx->readret = ReadFile(ctx->h, ctx->buffer, sizeof(ctx->buffer), - &ctx->len, povl); - if (povl && !ctx->readret && GetLastError() == ERROR_IO_PENDING) - ctx->readret = GetOverlappedResult(ctx->h, povl, &ctx->len, TRUE); + povl->hEvent = oev; + } + 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); + 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; @@ -132,6 +173,9 @@ static DWORD WINAPI handle_input_threadfunc(void *param) break; /* main thread told us to shut down */ } + if (povl) + CloseHandle(oev); + return 0; } @@ -200,12 +244,13 @@ struct handle_output { * 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. */ bufchain queued_data; /* data still waiting to be written */ + enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof; /* * Callback function called when the backlog in the bufchain @@ -218,11 +263,15 @@ static DWORD WINAPI handle_output_threadfunc(void *param) { struct handle_output *ctx = (struct handle_output *) param; OVERLAPPED ovl, *povl; + HANDLE oev; + int writeret; - if (ctx->flags & HANDLE_FLAG_OVERLAPPED) + if (ctx->flags & HANDLE_FLAG_OVERLAPPED) { povl = &ovl; - else + oev = CreateEvent(NULL, TRUE, FALSE, NULL); + } else { povl = NULL; + } while (1) { WaitForSingleObject(ctx->ev_from_main, INFINITE); @@ -230,19 +279,34 @@ static DWORD WINAPI handle_output_threadfunc(void *param) SetEvent(ctx->ev_to_main); break; } - if (povl) + 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); + povl->hEvent = oev; + } + + 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; } + if (povl) + CloseHandle(oev); + return 0; } @@ -257,6 +321,11 @@ static void handle_try_output(struct handle_output *ctx) ctx->len = sendlen; SetEvent(ctx->ev_from_main); ctx->busy = TRUE; + } else if (!ctx->busy && bufchain_size(&ctx->queued_data) == 0 && + ctx->outgoingeof == EOF_PENDING) { + CloseHandle(ctx->h); + ctx->h = INVALID_HANDLE_VALUE; + ctx->outgoingeof = EOF_SENT; } } @@ -305,6 +374,7 @@ struct handle *handle_input_new(HANDLE handle, handle_inputfn_t gotdata, void *privdata, int flags) { struct handle *h = snew(struct handle); + DWORD in_threadid; /* required for Win9x */ h->output = FALSE; h->u.i.h = handle; @@ -322,7 +392,7 @@ struct handle *handle_input_new(HANDLE handle, handle_inputfn_t gotdata, 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; @@ -332,6 +402,7 @@ struct handle *handle_output_new(HANDLE handle, handle_outputfn_t sentdata, void *privdata, int flags) { struct handle *h = snew(struct handle); + DWORD out_threadid; /* required for Win9x */ h->output = TRUE; h->u.o.h = handle; @@ -343,6 +414,7 @@ struct handle *handle_output_new(HANDLE handle, handle_outputfn_t sentdata, h->u.o.done = FALSE; h->u.o.privdata = privdata; bufchain_init(&h->u.o.queued_data); + h->u.o.outgoingeof = EOF_NO; h->u.o.sentdata = sentdata; h->u.o.flags = flags; @@ -351,7 +423,7 @@ struct handle *handle_output_new(HANDLE handle, handle_outputfn_t sentdata, add234(handles_by_evtomain, h); CreateThread(NULL, 0, handle_output_threadfunc, - &h->u.i, 0, NULL); + &h->u.o, 0, &out_threadid); return h; } @@ -359,11 +431,28 @@ struct handle *handle_output_new(HANDLE handle, handle_outputfn_t sentdata, int handle_write(struct handle *h, const void *data, int len) { assert(h->output); + assert(h->u.o.outgoingeof == EOF_NO); bufchain_add(&h->u.o.queued_data, data, len); handle_try_output(&h->u.o); return bufchain_size(&h->u.o.queued_data); } +void handle_write_eof(struct handle *h) +{ + /* + * This function is called when we want to proactively send an + * end-of-file notification on the handle. We can only do this by + * actually closing the handle - so never call this on a + * bidirectional handle if we're still interested in its incoming + * direction! + */ + assert(h->output); + if (!h->u.o.outgoingeof == EOF_NO) { + h->u.o.outgoingeof = EOF_PENDING; + handle_try_output(&h->u.o); + } +} + HANDLE *handle_get_events(int *nevents) { HANDLE *ret; @@ -483,7 +572,7 @@ void handle_got_event(HANDLE event) /* * 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); @@ -497,13 +586,13 @@ void handle_got_event(HANDLE event) * 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);