From a3fe3e22d85e8aa795df85c21814fc84cac42e99 Mon Sep 17 00:00:00 2001 From: marha Date: Mon, 14 Apr 2014 23:43:21 +0200 Subject: plink: updated to revision 10170 of putty --- tools/plink/winhandl.c | 1303 +++++++++++++++++++++++++----------------------- 1 file changed, 683 insertions(+), 620 deletions(-) (limited to 'tools/plink/winhandl.c') diff --git a/tools/plink/winhandl.c b/tools/plink/winhandl.c index 06c2a6a07..b15d1f262 100644 --- a/tools/plink/winhandl.c +++ b/tools/plink/winhandl.c @@ -1,620 +1,683 @@ -/* - * winhandl.c: Module to give Windows front ends the general - * ability to deal with consoles, pipes, serial ports, or any other - * type of data stream accessed through a Windows API HANDLE rather - * than a WinSock SOCKET. - * - * We do this by spawning a subthread to continuously try to read - * from the handle. Every time a read successfully returns some - * data, the subthread sets an event object which is picked up by - * the main thread, and the main thread then sets an event in - * return to instruct the subthread to resume reading. - * - * Output works precisely the other way round, in a second - * subthread. The output subthread should not be attempting to - * write all the time, because it hasn't always got data _to_ - * 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 - -#include "putty.h" - -/* ---------------------------------------------------------------------- - * Generic definitions. - */ - -/* - * Maximum amount of backlog we will allow to build up on an input - * handle before we stop reading from it. - */ -#define MAX_BACKLOG 32768 - -struct handle_generic { - /* - * Initial fields common to both handle_input and handle_output - * structures. - * - * The three HANDLEs are set up at initialisation time and are - * thereafter read-only to both main thread and subthread. - * `moribund' is only used by the main thread; `done' is - * written by the main thread before signalling to the - * subthread. `defunct' and `busy' are used only by the main - * thread. - */ - HANDLE h; /* the handle itself */ - HANDLE ev_to_main; /* event used to signal main thread */ - HANDLE ev_from_main; /* event used to signal back to us */ - int moribund; /* are we going to kill this soon? */ - int done; /* request subthread to terminate */ - int defunct; /* has the subthread already gone? */ - int busy; /* operation currently in progress? */ - void *privdata; /* for client to remember who they are */ -}; - -/* ---------------------------------------------------------------------- - * Input threads. - */ - -/* - * Data required by an input thread. - */ -struct handle_input { - /* - * Copy of the handle_generic structure. - */ - HANDLE h; /* the handle itself */ - HANDLE ev_to_main; /* event used to signal main thread */ - HANDLE ev_from_main; /* event used to signal back to us */ - int moribund; /* are we going to kill this soon? */ - int done; /* request subthread to terminate */ - int defunct; /* has the subthread already gone? */ - int busy; /* operation currently in progress? */ - void *privdata; /* for client to remember who they are */ - - /* - * Data set at initialisation and then read-only. - */ - int flags; - - /* - * Data set by the input thread before signalling ev_to_main, - * and read by the main thread after receiving that signal. - */ - char buffer[4096]; /* the data read from the handle */ - DWORD len; /* how much data that was */ - int readerr; /* lets us know about read errors */ - - /* - * Callback function called by this module when data arrives on - * an input handle. - */ - handle_inputfn_t gotdata; -}; - -/* - * The actual thread procedure for an input thread. - */ -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) { - povl = &ovl; - 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) { - memset(povl, 0, sizeof(OVERLAPPED)); - 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 (!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 (readret && ctx->len == 0 && - (ctx->flags & HANDLE_FLAG_IGNOREEOF)) - continue; - - SetEvent(ctx->ev_to_main); - - if (!ctx->len) - break; - - WaitForSingleObject(ctx->ev_from_main, INFINITE); - if (ctx->done) - break; /* main thread told us to shut down */ - } - - if (povl) - CloseHandle(oev); - - return 0; -} - -/* - * This is called after a succcessful read, or from the - * `unthrottle' function. It decides whether or not to begin a new - * read operation. - */ -static void handle_throttle(struct handle_input *ctx, int backlog) -{ - if (ctx->defunct) - return; - - /* - * If there's a read operation already in progress, do nothing: - * when that completes, we'll come back here and be in a - * position to make a better decision. - */ - if (ctx->busy) - return; - - /* - * Otherwise, we must decide whether to start a new read based - * on the size of the backlog. - */ - if (backlog < MAX_BACKLOG) { - SetEvent(ctx->ev_from_main); - ctx->busy = TRUE; - } -} - -/* ---------------------------------------------------------------------- - * Output threads. - */ - -/* - * Data required by an output thread. - */ -struct handle_output { - /* - * Copy of the handle_generic structure. - */ - HANDLE h; /* the handle itself */ - HANDLE ev_to_main; /* event used to signal main thread */ - HANDLE ev_from_main; /* event used to signal back to us */ - int moribund; /* are we going to kill this soon? */ - int done; /* request subthread to terminate */ - int defunct; /* has the subthread already gone? */ - int busy; /* operation currently in progress? */ - void *privdata; /* for client to remember who they are */ - - /* - * Data set at initialisation and then read-only. - */ - int flags; - - /* - * Data set by the main thread before signalling ev_from_main, - * and read by the input thread after receiving that signal. - */ - char *buffer; /* the data to write */ - DWORD len; /* how much data there is */ - - /* - * Data set by the input thread before signalling ev_to_main, - * and read by the main thread after receiving that signal. - */ - DWORD lenwritten; /* how much data we actually wrote */ - 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 - * drops. - */ - handle_outputfn_t sentdata; -}; - -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) { - povl = &ovl; - oev = CreateEvent(NULL, TRUE, FALSE, NULL); - } else { - povl = NULL; - } - - while (1) { - WaitForSingleObject(ctx->ev_from_main, INFINITE); - if (ctx->done) { - SetEvent(ctx->ev_to_main); - break; - } - if (povl) { - memset(povl, 0, sizeof(OVERLAPPED)); - 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 (!writeret) - break; - } - - if (povl) - CloseHandle(oev); - - return 0; -} - -static void handle_try_output(struct handle_output *ctx) -{ - void *senddata; - int sendlen; - - if (!ctx->busy && bufchain_size(&ctx->queued_data)) { - bufchain_prefix(&ctx->queued_data, &senddata, &sendlen); - ctx->buffer = senddata; - 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; - } -} - -/* ---------------------------------------------------------------------- - * Unified code handling both input and output threads. - */ - -struct handle { - int output; - union { - struct handle_generic g; - struct handle_input i; - struct handle_output o; - } u; -}; - -static tree234 *handles_by_evtomain; - -static int handle_cmp_evtomain(void *av, void *bv) -{ - struct handle *a = (struct handle *)av; - struct handle *b = (struct handle *)bv; - - if ((unsigned)a->u.g.ev_to_main < (unsigned)b->u.g.ev_to_main) - return -1; - else if ((unsigned)a->u.g.ev_to_main > (unsigned)b->u.g.ev_to_main) - return +1; - else - return 0; -} - -static int handle_find_evtomain(void *av, void *bv) -{ - HANDLE *a = (HANDLE *)av; - struct handle *b = (struct handle *)bv; - - if ((unsigned)*a < (unsigned)b->u.g.ev_to_main) - return -1; - else if ((unsigned)*a > (unsigned)b->u.g.ev_to_main) - return +1; - else - return 0; -} - -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; - h->u.i.ev_to_main = CreateEvent(NULL, FALSE, FALSE, NULL); - h->u.i.ev_from_main = CreateEvent(NULL, FALSE, FALSE, NULL); - h->u.i.gotdata = gotdata; - h->u.i.defunct = FALSE; - h->u.i.moribund = FALSE; - h->u.i.done = FALSE; - h->u.i.privdata = privdata; - h->u.i.flags = flags; - - if (!handles_by_evtomain) - handles_by_evtomain = newtree234(handle_cmp_evtomain); - add234(handles_by_evtomain, h); - - CreateThread(NULL, 0, handle_input_threadfunc, - &h->u.i, 0, &in_threadid); - h->u.i.busy = TRUE; - - return h; -} - -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; - h->u.o.ev_to_main = CreateEvent(NULL, FALSE, FALSE, NULL); - h->u.o.ev_from_main = CreateEvent(NULL, FALSE, FALSE, NULL); - h->u.o.busy = FALSE; - h->u.o.defunct = FALSE; - h->u.o.moribund = FALSE; - 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; - - if (!handles_by_evtomain) - handles_by_evtomain = newtree234(handle_cmp_evtomain); - add234(handles_by_evtomain, h); - - CreateThread(NULL, 0, handle_output_threadfunc, - &h->u.o, 0, &out_threadid); - - return h; -} - -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; - struct handle *h; - int i, n, size; - - /* - * Go through our tree counting the handle objects currently - * engaged in useful activity. - */ - ret = NULL; - n = size = 0; - if (handles_by_evtomain) { - for (i = 0; (h = index234(handles_by_evtomain, i)) != NULL; i++) { - if (h->u.g.busy) { - if (n >= size) { - size += 32; - ret = sresize(ret, size, HANDLE); - } - ret[n++] = h->u.g.ev_to_main; - } - } - } - - *nevents = n; - return ret; -} - -static void handle_destroy(struct handle *h) -{ - if (h->output) - bufchain_clear(&h->u.o.queued_data); - CloseHandle(h->u.g.ev_from_main); - CloseHandle(h->u.g.ev_to_main); - del234(handles_by_evtomain, h); - sfree(h); -} - -void handle_free(struct handle *h) -{ - /* - * If the handle is currently busy, we cannot immediately free - * it. Instead we must wait until it's finished its current - * operation, because otherwise the subthread will write to - * invalid memory after we free its context from under it. - */ - assert(h && !h->u.g.moribund); - if (h->u.g.busy) { - /* - * Just set the moribund flag, which will be noticed next - * time an operation completes. - */ - h->u.g.moribund = TRUE; - } else if (h->u.g.defunct) { - /* - * There isn't even a subthread; we can go straight to - * handle_destroy. - */ - handle_destroy(h); - } else { - /* - * The subthread is alive but not busy, so we now signal it - * to die. Set the moribund flag to indicate that it will - * want destroying after that. - */ - h->u.g.moribund = TRUE; - h->u.g.done = TRUE; - h->u.g.busy = TRUE; - SetEvent(h->u.g.ev_from_main); - } -} - -void handle_got_event(HANDLE event) -{ - struct handle *h; - - assert(handles_by_evtomain); - h = find234(handles_by_evtomain, &event, handle_find_evtomain); - if (!h) { - /* - * This isn't an error condition. If two or more event - * objects were signalled during the same select operation, - * and processing of the first caused the second handle to - * be closed, then it will sometimes happen that we receive - * an event notification here for a handle which is already - * deceased. In that situation we simply do nothing. - */ - return; - } - - if (h->u.g.moribund) { - /* - * A moribund handle is already treated as dead from the - * external user's point of view, so do nothing with the - * actual event. Just signal the thread to die if - * necessary, or destroy the handle if not. - */ - if (h->u.g.done) { - handle_destroy(h); - } else { - h->u.g.done = TRUE; - h->u.g.busy = TRUE; - SetEvent(h->u.g.ev_from_main); - } - return; - } - - if (!h->output) { - int backlog; - - h->u.i.busy = FALSE; - - /* - * A signal on an input handle means data has arrived. - */ - if (h->u.i.len == 0) { - /* - * EOF, or (nearly equivalently) read error. - */ - 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); - handle_throttle(&h->u.i, backlog); - } - } else { - h->u.o.busy = FALSE; - - /* - * A signal on an output handle means we have completed a - * write. Call the callback to indicate that the output - * buffer size has decreased, or to indicate an error. - */ - 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, -h->u.o.writeerr); - h->u.o.defunct = TRUE; - } else { - bufchain_consume(&h->u.o.queued_data, h->u.o.lenwritten); - h->u.o.sentdata(h, bufchain_size(&h->u.o.queued_data)); - handle_try_output(&h->u.o); - } - } -} - -void handle_unthrottle(struct handle *h, int backlog) -{ - assert(!h->output); - handle_throttle(&h->u.i, backlog); -} - -int handle_backlog(struct handle *h) -{ - assert(h->output); - return bufchain_size(&h->u.o.queued_data); -} - -void *handle_get_privdata(struct handle *h) -{ - return h->u.g.privdata; -} +/* + * winhandl.c: Module to give Windows front ends the general + * ability to deal with consoles, pipes, serial ports, or any other + * type of data stream accessed through a Windows API HANDLE rather + * than a WinSock SOCKET. + * + * We do this by spawning a subthread to continuously try to read + * from the handle. Every time a read successfully returns some + * data, the subthread sets an event object which is picked up by + * the main thread, and the main thread then sets an event in + * return to instruct the subthread to resume reading. + * + * Output works precisely the other way round, in a second + * subthread. The output subthread should not be attempting to + * write all the time, because it hasn't always got data _to_ + * 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 + +#include "putty.h" + +/* ---------------------------------------------------------------------- + * Generic definitions. + */ + +/* + * Maximum amount of backlog we will allow to build up on an input + * handle before we stop reading from it. + */ +#define MAX_BACKLOG 32768 + +struct handle_generic { + /* + * Initial fields common to both handle_input and handle_output + * structures. + * + * The three HANDLEs are set up at initialisation time and are + * thereafter read-only to both main thread and subthread. + * `moribund' is only used by the main thread; `done' is + * written by the main thread before signalling to the + * subthread. `defunct' and `busy' are used only by the main + * thread. + */ + HANDLE h; /* the handle itself */ + HANDLE ev_to_main; /* event used to signal main thread */ + HANDLE ev_from_main; /* event used to signal back to us */ + int moribund; /* are we going to kill this soon? */ + int done; /* request subthread to terminate */ + int defunct; /* has the subthread already gone? */ + int busy; /* operation currently in progress? */ + void *privdata; /* for client to remember who they are */ +}; + +typedef enum { HT_INPUT, HT_OUTPUT, HT_FOREIGN } HandleType; + +/* ---------------------------------------------------------------------- + * Input threads. + */ + +/* + * Data required by an input thread. + */ +struct handle_input { + /* + * Copy of the handle_generic structure. + */ + HANDLE h; /* the handle itself */ + HANDLE ev_to_main; /* event used to signal main thread */ + HANDLE ev_from_main; /* event used to signal back to us */ + int moribund; /* are we going to kill this soon? */ + int done; /* request subthread to terminate */ + int defunct; /* has the subthread already gone? */ + int busy; /* operation currently in progress? */ + void *privdata; /* for client to remember who they are */ + + /* + * Data set at initialisation and then read-only. + */ + int flags; + + /* + * Data set by the input thread before signalling ev_to_main, + * and read by the main thread after receiving that signal. + */ + char buffer[4096]; /* the data read from the handle */ + DWORD len; /* how much data that was */ + int readerr; /* lets us know about read errors */ + + /* + * Callback function called by this module when data arrives on + * an input handle. + */ + handle_inputfn_t gotdata; +}; + +/* + * The actual thread procedure for an input thread. + */ +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) { + povl = &ovl; + 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) { + memset(povl, 0, sizeof(OVERLAPPED)); + 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 (!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 (readret && ctx->len == 0 && + (ctx->flags & HANDLE_FLAG_IGNOREEOF)) + continue; + + SetEvent(ctx->ev_to_main); + + if (!ctx->len) + break; + + WaitForSingleObject(ctx->ev_from_main, INFINITE); + if (ctx->done) + break; /* main thread told us to shut down */ + } + + if (povl) + CloseHandle(oev); + + return 0; +} + +/* + * This is called after a succcessful read, or from the + * `unthrottle' function. It decides whether or not to begin a new + * read operation. + */ +static void handle_throttle(struct handle_input *ctx, int backlog) +{ + if (ctx->defunct) + return; + + /* + * If there's a read operation already in progress, do nothing: + * when that completes, we'll come back here and be in a + * position to make a better decision. + */ + if (ctx->busy) + return; + + /* + * Otherwise, we must decide whether to start a new read based + * on the size of the backlog. + */ + if (backlog < MAX_BACKLOG) { + SetEvent(ctx->ev_from_main); + ctx->busy = TRUE; + } +} + +/* ---------------------------------------------------------------------- + * Output threads. + */ + +/* + * Data required by an output thread. + */ +struct handle_output { + /* + * Copy of the handle_generic structure. + */ + HANDLE h; /* the handle itself */ + HANDLE ev_to_main; /* event used to signal main thread */ + HANDLE ev_from_main; /* event used to signal back to us */ + int moribund; /* are we going to kill this soon? */ + int done; /* request subthread to terminate */ + int defunct; /* has the subthread already gone? */ + int busy; /* operation currently in progress? */ + void *privdata; /* for client to remember who they are */ + + /* + * Data set at initialisation and then read-only. + */ + int flags; + + /* + * Data set by the main thread before signalling ev_from_main, + * and read by the input thread after receiving that signal. + */ + char *buffer; /* the data to write */ + DWORD len; /* how much data there is */ + + /* + * Data set by the input thread before signalling ev_to_main, + * and read by the main thread after receiving that signal. + */ + DWORD lenwritten; /* how much data we actually wrote */ + 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 + * drops. + */ + handle_outputfn_t sentdata; +}; + +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) { + povl = &ovl; + oev = CreateEvent(NULL, TRUE, FALSE, NULL); + } else { + povl = NULL; + } + + while (1) { + WaitForSingleObject(ctx->ev_from_main, INFINITE); + if (ctx->done) { + SetEvent(ctx->ev_to_main); + break; + } + if (povl) { + memset(povl, 0, sizeof(OVERLAPPED)); + 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 (!writeret) + break; + } + + if (povl) + CloseHandle(oev); + + return 0; +} + +static void handle_try_output(struct handle_output *ctx) +{ + void *senddata; + int sendlen; + + if (!ctx->busy && bufchain_size(&ctx->queued_data)) { + bufchain_prefix(&ctx->queued_data, &senddata, &sendlen); + ctx->buffer = senddata; + 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; + } +} + +/* ---------------------------------------------------------------------- + * 'Foreign events'. These are handle structures which just contain a + * single event object passed to us by another module such as + * winnps.c, so that they can make use of our handle_get_events / + * handle_got_event mechanism for communicating with application main + * loops. + */ +struct handle_foreign { + /* + * Copy of the handle_generic structure. + */ + HANDLE h; /* the handle itself */ + HANDLE ev_to_main; /* event used to signal main thread */ + HANDLE ev_from_main; /* event used to signal back to us */ + int moribund; /* are we going to kill this soon? */ + int done; /* request subthread to terminate */ + int defunct; /* has the subthread already gone? */ + int busy; /* operation currently in progress? */ + void *privdata; /* for client to remember who they are */ + + /* + * Our own data, just consisting of knowledge of who to call back. + */ + void (*callback)(void *); + void *ctx; +}; + +/* ---------------------------------------------------------------------- + * Unified code handling both input and output threads. + */ + +struct handle { + HandleType type; + union { + struct handle_generic g; + struct handle_input i; + struct handle_output o; + struct handle_foreign f; + } u; +}; + +static tree234 *handles_by_evtomain; + +static int handle_cmp_evtomain(void *av, void *bv) +{ + struct handle *a = (struct handle *)av; + struct handle *b = (struct handle *)bv; + + if ((unsigned)a->u.g.ev_to_main < (unsigned)b->u.g.ev_to_main) + return -1; + else if ((unsigned)a->u.g.ev_to_main > (unsigned)b->u.g.ev_to_main) + return +1; + else + return 0; +} + +static int handle_find_evtomain(void *av, void *bv) +{ + HANDLE *a = (HANDLE *)av; + struct handle *b = (struct handle *)bv; + + if ((unsigned)*a < (unsigned)b->u.g.ev_to_main) + return -1; + else if ((unsigned)*a > (unsigned)b->u.g.ev_to_main) + return +1; + else + return 0; +} + +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->type = HT_INPUT; + h->u.i.h = handle; + h->u.i.ev_to_main = CreateEvent(NULL, FALSE, FALSE, NULL); + h->u.i.ev_from_main = CreateEvent(NULL, FALSE, FALSE, NULL); + h->u.i.gotdata = gotdata; + h->u.i.defunct = FALSE; + h->u.i.moribund = FALSE; + h->u.i.done = FALSE; + h->u.i.privdata = privdata; + h->u.i.flags = flags; + + if (!handles_by_evtomain) + handles_by_evtomain = newtree234(handle_cmp_evtomain); + add234(handles_by_evtomain, h); + + CreateThread(NULL, 0, handle_input_threadfunc, + &h->u.i, 0, &in_threadid); + h->u.i.busy = TRUE; + + return h; +} + +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->type = HT_OUTPUT; + h->u.o.h = handle; + h->u.o.ev_to_main = CreateEvent(NULL, FALSE, FALSE, NULL); + h->u.o.ev_from_main = CreateEvent(NULL, FALSE, FALSE, NULL); + h->u.o.busy = FALSE; + h->u.o.defunct = FALSE; + h->u.o.moribund = FALSE; + 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; + + if (!handles_by_evtomain) + handles_by_evtomain = newtree234(handle_cmp_evtomain); + add234(handles_by_evtomain, h); + + CreateThread(NULL, 0, handle_output_threadfunc, + &h->u.o, 0, &out_threadid); + + return h; +} + +struct handle *handle_add_foreign_event(HANDLE event, + void (*callback)(void *), void *ctx) +{ + struct handle *h = snew(struct handle); + + h->type = HT_FOREIGN; + h->u.f.h = INVALID_HANDLE_VALUE; + h->u.f.ev_to_main = event; + h->u.f.ev_from_main = INVALID_HANDLE_VALUE; + h->u.f.defunct = TRUE; /* we have no thread in the first place */ + h->u.f.moribund = FALSE; + h->u.f.done = FALSE; + h->u.f.privdata = NULL; + h->u.f.callback = callback; + h->u.f.ctx = ctx; + h->u.f.busy = TRUE; + + if (!handles_by_evtomain) + handles_by_evtomain = newtree234(handle_cmp_evtomain); + add234(handles_by_evtomain, h); + + return h; +} + +int handle_write(struct handle *h, const void *data, int len) +{ + assert(h->type == HT_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->type == HT_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; + struct handle *h; + int i, n, size; + + /* + * Go through our tree counting the handle objects currently + * engaged in useful activity. + */ + ret = NULL; + n = size = 0; + if (handles_by_evtomain) { + for (i = 0; (h = index234(handles_by_evtomain, i)) != NULL; i++) { + if (h->u.g.busy) { + if (n >= size) { + size += 32; + ret = sresize(ret, size, HANDLE); + } + ret[n++] = h->u.g.ev_to_main; + } + } + } + + *nevents = n; + return ret; +} + +static void handle_destroy(struct handle *h) +{ + if (h->type == HT_OUTPUT) + bufchain_clear(&h->u.o.queued_data); + CloseHandle(h->u.g.ev_from_main); + CloseHandle(h->u.g.ev_to_main); + del234(handles_by_evtomain, h); + sfree(h); +} + +void handle_free(struct handle *h) +{ + /* + * If the handle is currently busy, we cannot immediately free + * it. Instead we must wait until it's finished its current + * operation, because otherwise the subthread will write to + * invalid memory after we free its context from under it. + */ + assert(h && !h->u.g.moribund); + if (h->u.g.busy) { + /* + * Just set the moribund flag, which will be noticed next + * time an operation completes. + */ + h->u.g.moribund = TRUE; + } else if (h->u.g.defunct) { + /* + * There isn't even a subthread; we can go straight to + * handle_destroy. + */ + handle_destroy(h); + } else { + /* + * The subthread is alive but not busy, so we now signal it + * to die. Set the moribund flag to indicate that it will + * want destroying after that. + */ + h->u.g.moribund = TRUE; + h->u.g.done = TRUE; + h->u.g.busy = TRUE; + SetEvent(h->u.g.ev_from_main); + } +} + +void handle_got_event(HANDLE event) +{ + struct handle *h; + + assert(handles_by_evtomain); + h = find234(handles_by_evtomain, &event, handle_find_evtomain); + if (!h) { + /* + * This isn't an error condition. If two or more event + * objects were signalled during the same select operation, + * and processing of the first caused the second handle to + * be closed, then it will sometimes happen that we receive + * an event notification here for a handle which is already + * deceased. In that situation we simply do nothing. + */ + return; + } + + if (h->u.g.moribund) { + /* + * A moribund handle is already treated as dead from the + * external user's point of view, so do nothing with the + * actual event. Just signal the thread to die if + * necessary, or destroy the handle if not. + */ + if (h->u.g.done) { + handle_destroy(h); + } else { + h->u.g.done = TRUE; + h->u.g.busy = TRUE; + SetEvent(h->u.g.ev_from_main); + } + return; + } + + switch (h->type) { + int backlog; + + case HT_INPUT: + h->u.i.busy = FALSE; + + /* + * A signal on an input handle means data has arrived. + */ + if (h->u.i.len == 0) { + /* + * EOF, or (nearly equivalently) read error. + */ + 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); + handle_throttle(&h->u.i, backlog); + } + break; + + case HT_OUTPUT: + h->u.o.busy = FALSE; + + /* + * A signal on an output handle means we have completed a + * write. Call the callback to indicate that the output + * buffer size has decreased, or to indicate an error. + */ + 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, -h->u.o.writeerr); + h->u.o.defunct = TRUE; + } else { + bufchain_consume(&h->u.o.queued_data, h->u.o.lenwritten); + h->u.o.sentdata(h, bufchain_size(&h->u.o.queued_data)); + handle_try_output(&h->u.o); + } + break; + + case HT_FOREIGN: + /* Just call the callback. */ + h->u.f.callback(h->u.f.ctx); + break; + } +} + +void handle_unthrottle(struct handle *h, int backlog) +{ + assert(h->type == HT_INPUT); + handle_throttle(&h->u.i, backlog); +} + +int handle_backlog(struct handle *h) +{ + assert(h->type == HT_OUTPUT); + return bufchain_size(&h->u.o.queued_data); +} + +void *handle_get_privdata(struct handle *h) +{ + return h->u.g.privdata; +} -- cgit v1.2.3