Merge branch 'os/gitweb-highlight-uncaptured' into maint
[git.git] / compat / poll / poll.c
blob7d226ecb293ee3c5f9b17aa3e5e36b7c8701dbae
1 /* Emulation for poll(2)
2 Contributed by Paolo Bonzini.
4 Copyright 2001-2003, 2006-2011 Free Software Foundation, Inc.
6 This file is part of gnulib.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation,
20 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
22 /* Tell gcc not to warn about the (nfd < 0) tests, below. */
23 #if (__GNUC__ == 4 && 3 <= __GNUC_MINOR__) || 4 < __GNUC__
24 # pragma GCC diagnostic ignored "-Wtype-limits"
25 #endif
27 #if defined(WIN32)
28 # include <malloc.h>
29 #endif
31 #include <sys/types.h>
33 /* Specification. */
34 #include <poll.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <assert.h>
40 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
41 # define WIN32_NATIVE
42 # if defined (_MSC_VER)
43 # define _WIN32_WINNT 0x0502
44 # endif
45 # include <winsock2.h>
46 # include <windows.h>
47 # include <io.h>
48 # include <stdio.h>
49 # include <conio.h>
50 #else
51 # include <sys/time.h>
52 # include <sys/socket.h>
53 # ifndef NO_SYS_SELECT_H
54 # include <sys/select.h>
55 # endif
56 # include <unistd.h>
57 #endif
59 #ifdef HAVE_SYS_IOCTL_H
60 # include <sys/ioctl.h>
61 #endif
62 #ifdef HAVE_SYS_FILIO_H
63 # include <sys/filio.h>
64 #endif
66 #include <time.h>
68 #ifndef INFTIM
69 # define INFTIM (-1)
70 #endif
72 /* BeOS does not have MSG_PEEK. */
73 #ifndef MSG_PEEK
74 # define MSG_PEEK 0
75 #endif
77 #ifdef WIN32_NATIVE
79 #define IsConsoleHandle(h) (((long) (h) & 3) == 3)
81 static BOOL
82 IsSocketHandle (HANDLE h)
84 WSANETWORKEVENTS ev;
86 if (IsConsoleHandle (h))
87 return FALSE;
89 /* Under Wine, it seems that getsockopt returns 0 for pipes too.
90 WSAEnumNetworkEvents instead distinguishes the two correctly. */
91 ev.lNetworkEvents = 0xDEADBEEF;
92 WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
93 return ev.lNetworkEvents != 0xDEADBEEF;
96 /* Declare data structures for ntdll functions. */
97 typedef struct _FILE_PIPE_LOCAL_INFORMATION {
98 ULONG NamedPipeType;
99 ULONG NamedPipeConfiguration;
100 ULONG MaximumInstances;
101 ULONG CurrentInstances;
102 ULONG InboundQuota;
103 ULONG ReadDataAvailable;
104 ULONG OutboundQuota;
105 ULONG WriteQuotaAvailable;
106 ULONG NamedPipeState;
107 ULONG NamedPipeEnd;
108 } FILE_PIPE_LOCAL_INFORMATION, *PFILE_PIPE_LOCAL_INFORMATION;
110 typedef struct _IO_STATUS_BLOCK
112 union {
113 DWORD Status;
114 PVOID Pointer;
115 } u;
116 ULONG_PTR Information;
117 } IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
119 typedef enum _FILE_INFORMATION_CLASS {
120 FilePipeLocalInformation = 24
121 } FILE_INFORMATION_CLASS, *PFILE_INFORMATION_CLASS;
123 typedef DWORD (WINAPI *PNtQueryInformationFile)
124 (HANDLE, IO_STATUS_BLOCK *, VOID *, ULONG, FILE_INFORMATION_CLASS);
126 # ifndef PIPE_BUF
127 # define PIPE_BUF 512
128 # endif
130 /* Compute revents values for file handle H. If some events cannot happen
131 for the handle, eliminate them from *P_SOUGHT. */
133 static int
134 win32_compute_revents (HANDLE h, int *p_sought)
136 int i, ret, happened;
137 INPUT_RECORD *irbuffer;
138 DWORD avail, nbuffer;
139 BOOL bRet;
140 IO_STATUS_BLOCK iosb;
141 FILE_PIPE_LOCAL_INFORMATION fpli;
142 static PNtQueryInformationFile NtQueryInformationFile;
143 static BOOL once_only;
145 switch (GetFileType (h))
147 case FILE_TYPE_PIPE:
148 if (!once_only)
150 NtQueryInformationFile = (PNtQueryInformationFile)
151 GetProcAddress (GetModuleHandle ("ntdll.dll"),
152 "NtQueryInformationFile");
153 once_only = TRUE;
156 happened = 0;
157 if (PeekNamedPipe (h, NULL, 0, NULL, &avail, NULL) != 0)
159 if (avail)
160 happened |= *p_sought & (POLLIN | POLLRDNORM);
162 else if (GetLastError () == ERROR_BROKEN_PIPE)
163 happened |= POLLHUP;
165 else
167 /* It was the write-end of the pipe. Check if it is writable.
168 If NtQueryInformationFile fails, optimistically assume the pipe is
169 writable. This could happen on Win9x, where NtQueryInformationFile
170 is not available, or if we inherit a pipe that doesn't permit
171 FILE_READ_ATTRIBUTES access on the write end (I think this should
172 not happen since WinXP SP2; WINE seems fine too). Otherwise,
173 ensure that enough space is available for atomic writes. */
174 memset (&iosb, 0, sizeof (iosb));
175 memset (&fpli, 0, sizeof (fpli));
177 if (!NtQueryInformationFile
178 || NtQueryInformationFile (h, &iosb, &fpli, sizeof (fpli),
179 FilePipeLocalInformation)
180 || fpli.WriteQuotaAvailable >= PIPE_BUF
181 || (fpli.OutboundQuota < PIPE_BUF &&
182 fpli.WriteQuotaAvailable == fpli.OutboundQuota))
183 happened |= *p_sought & (POLLOUT | POLLWRNORM | POLLWRBAND);
185 return happened;
187 case FILE_TYPE_CHAR:
188 ret = WaitForSingleObject (h, 0);
189 if (!IsConsoleHandle (h))
190 return ret == WAIT_OBJECT_0 ? *p_sought & ~(POLLPRI | POLLRDBAND) : 0;
192 nbuffer = avail = 0;
193 bRet = GetNumberOfConsoleInputEvents (h, &nbuffer);
194 if (bRet)
196 /* Input buffer. */
197 *p_sought &= POLLIN | POLLRDNORM;
198 if (nbuffer == 0)
199 return POLLHUP;
200 if (!*p_sought)
201 return 0;
203 irbuffer = (INPUT_RECORD *) alloca (nbuffer * sizeof (INPUT_RECORD));
204 bRet = PeekConsoleInput (h, irbuffer, nbuffer, &avail);
205 if (!bRet || avail == 0)
206 return POLLHUP;
208 for (i = 0; i < avail; i++)
209 if (irbuffer[i].EventType == KEY_EVENT)
210 return *p_sought;
211 return 0;
213 else
215 /* Screen buffer. */
216 *p_sought &= POLLOUT | POLLWRNORM | POLLWRBAND;
217 return *p_sought;
220 default:
221 ret = WaitForSingleObject (h, 0);
222 if (ret == WAIT_OBJECT_0)
223 return *p_sought & ~(POLLPRI | POLLRDBAND);
225 return *p_sought & (POLLOUT | POLLWRNORM | POLLWRBAND);
229 /* Convert fd_sets returned by select into revents values. */
231 static int
232 win32_compute_revents_socket (SOCKET h, int sought, long lNetworkEvents)
234 int happened = 0;
236 if ((lNetworkEvents & (FD_READ | FD_ACCEPT | FD_CLOSE)) == FD_ACCEPT)
237 happened |= (POLLIN | POLLRDNORM) & sought;
239 else if (lNetworkEvents & (FD_READ | FD_ACCEPT | FD_CLOSE))
241 int r, error;
243 char data[64];
244 WSASetLastError (0);
245 r = recv (h, data, sizeof (data), MSG_PEEK);
246 error = WSAGetLastError ();
247 WSASetLastError (0);
249 if (r > 0 || error == WSAENOTCONN)
250 happened |= (POLLIN | POLLRDNORM) & sought;
252 /* Distinguish hung-up sockets from other errors. */
253 else if (r == 0 || error == WSAESHUTDOWN || error == WSAECONNRESET
254 || error == WSAECONNABORTED || error == WSAENETRESET)
255 happened |= POLLHUP;
257 else
258 happened |= POLLERR;
261 if (lNetworkEvents & (FD_WRITE | FD_CONNECT))
262 happened |= (POLLOUT | POLLWRNORM | POLLWRBAND) & sought;
264 if (lNetworkEvents & FD_OOB)
265 happened |= (POLLPRI | POLLRDBAND) & sought;
267 return happened;
270 #else /* !MinGW */
272 /* Convert select(2) returned fd_sets into poll(2) revents values. */
273 static int
274 compute_revents (int fd, int sought, fd_set *rfds, fd_set *wfds, fd_set *efds)
276 int happened = 0;
277 if (FD_ISSET (fd, rfds))
279 int r;
280 int socket_errno;
282 # if defined __MACH__ && defined __APPLE__
283 /* There is a bug in Mac OS X that causes it to ignore MSG_PEEK
284 for some kinds of descriptors. Detect if this descriptor is a
285 connected socket, a server socket, or something else using a
286 0-byte recv, and use ioctl(2) to detect POLLHUP. */
287 r = recv (fd, NULL, 0, MSG_PEEK);
288 socket_errno = (r < 0) ? errno : 0;
289 if (r == 0 || socket_errno == ENOTSOCK)
290 ioctl (fd, FIONREAD, &r);
291 # else
292 char data[64];
293 r = recv (fd, data, sizeof (data), MSG_PEEK);
294 socket_errno = (r < 0) ? errno : 0;
295 # endif
296 if (r == 0)
297 happened |= POLLHUP;
299 /* If the event happened on an unconnected server socket,
300 that's fine. */
301 else if (r > 0 || ( /* (r == -1) && */ socket_errno == ENOTCONN))
302 happened |= (POLLIN | POLLRDNORM) & sought;
304 /* Distinguish hung-up sockets from other errors. */
305 else if (socket_errno == ESHUTDOWN || socket_errno == ECONNRESET
306 || socket_errno == ECONNABORTED || socket_errno == ENETRESET)
307 happened |= POLLHUP;
309 /* some systems can't use recv() on non-socket, including HP NonStop */
310 else if (/* (r == -1) && */ socket_errno == ENOTSOCK)
311 happened |= (POLLIN | POLLRDNORM) & sought;
313 else
314 happened |= POLLERR;
317 if (FD_ISSET (fd, wfds))
318 happened |= (POLLOUT | POLLWRNORM | POLLWRBAND) & sought;
320 if (FD_ISSET (fd, efds))
321 happened |= (POLLPRI | POLLRDBAND) & sought;
323 return happened;
325 #endif /* !MinGW */
328 poll (struct pollfd *pfd, nfds_t nfd, int timeout)
330 #ifndef WIN32_NATIVE
331 fd_set rfds, wfds, efds;
332 struct timeval tv;
333 struct timeval *ptv;
334 int maxfd, rc;
335 nfds_t i;
337 # ifdef _SC_OPEN_MAX
338 static int sc_open_max = -1;
340 if (nfd < 0
341 || (nfd > sc_open_max
342 && (sc_open_max != -1
343 || nfd > (sc_open_max = sysconf (_SC_OPEN_MAX)))))
345 errno = EINVAL;
346 return -1;
348 # else /* !_SC_OPEN_MAX */
349 # ifdef OPEN_MAX
350 if (nfd < 0 || nfd > OPEN_MAX)
352 errno = EINVAL;
353 return -1;
355 # endif /* OPEN_MAX -- else, no check is needed */
356 # endif /* !_SC_OPEN_MAX */
358 /* EFAULT is not necessary to implement, but let's do it in the
359 simplest case. */
360 if (!pfd && nfd)
362 errno = EFAULT;
363 return -1;
366 /* convert timeout number into a timeval structure */
367 if (timeout == 0)
369 ptv = &tv;
370 ptv->tv_sec = 0;
371 ptv->tv_usec = 0;
373 else if (timeout > 0)
375 ptv = &tv;
376 ptv->tv_sec = timeout / 1000;
377 ptv->tv_usec = (timeout % 1000) * 1000;
379 else if (timeout == INFTIM)
380 /* wait forever */
381 ptv = NULL;
382 else
384 errno = EINVAL;
385 return -1;
388 /* create fd sets and determine max fd */
389 maxfd = -1;
390 FD_ZERO (&rfds);
391 FD_ZERO (&wfds);
392 FD_ZERO (&efds);
393 for (i = 0; i < nfd; i++)
395 if (pfd[i].fd < 0)
396 continue;
398 if (pfd[i].events & (POLLIN | POLLRDNORM))
399 FD_SET (pfd[i].fd, &rfds);
401 /* see select(2): "the only exceptional condition detectable
402 is out-of-band data received on a socket", hence we push
403 POLLWRBAND events onto wfds instead of efds. */
404 if (pfd[i].events & (POLLOUT | POLLWRNORM | POLLWRBAND))
405 FD_SET (pfd[i].fd, &wfds);
406 if (pfd[i].events & (POLLPRI | POLLRDBAND))
407 FD_SET (pfd[i].fd, &efds);
408 if (pfd[i].fd >= maxfd
409 && (pfd[i].events & (POLLIN | POLLOUT | POLLPRI
410 | POLLRDNORM | POLLRDBAND
411 | POLLWRNORM | POLLWRBAND)))
413 maxfd = pfd[i].fd;
414 if (maxfd > FD_SETSIZE)
416 errno = EOVERFLOW;
417 return -1;
422 /* examine fd sets */
423 rc = select (maxfd + 1, &rfds, &wfds, &efds, ptv);
424 if (rc < 0)
425 return rc;
427 /* establish results */
428 rc = 0;
429 for (i = 0; i < nfd; i++)
430 if (pfd[i].fd < 0)
431 pfd[i].revents = 0;
432 else
434 int happened = compute_revents (pfd[i].fd, pfd[i].events,
435 &rfds, &wfds, &efds);
436 if (happened)
438 pfd[i].revents = happened;
439 rc++;
443 return rc;
444 #else
445 static struct timeval tv0;
446 static HANDLE hEvent;
447 WSANETWORKEVENTS ev;
448 HANDLE h, handle_array[FD_SETSIZE + 2];
449 DWORD ret, wait_timeout, nhandles;
450 fd_set rfds, wfds, xfds;
451 BOOL poll_again;
452 MSG msg;
453 int rc = 0;
454 nfds_t i;
456 if (nfd < 0 || timeout < -1)
458 errno = EINVAL;
459 return -1;
462 if (!hEvent)
463 hEvent = CreateEvent (NULL, FALSE, FALSE, NULL);
465 restart:
466 handle_array[0] = hEvent;
467 nhandles = 1;
468 FD_ZERO (&rfds);
469 FD_ZERO (&wfds);
470 FD_ZERO (&xfds);
472 /* Classify socket handles and create fd sets. */
473 for (i = 0; i < nfd; i++)
475 int sought = pfd[i].events;
476 pfd[i].revents = 0;
477 if (pfd[i].fd < 0)
478 continue;
479 if (!(sought & (POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM | POLLWRBAND
480 | POLLPRI | POLLRDBAND)))
481 continue;
483 h = (HANDLE) _get_osfhandle (pfd[i].fd);
484 assert (h != NULL);
485 if (IsSocketHandle (h))
487 int requested = FD_CLOSE;
489 /* see above; socket handles are mapped onto select. */
490 if (sought & (POLLIN | POLLRDNORM))
492 requested |= FD_READ | FD_ACCEPT;
493 FD_SET ((SOCKET) h, &rfds);
495 if (sought & (POLLOUT | POLLWRNORM | POLLWRBAND))
497 requested |= FD_WRITE | FD_CONNECT;
498 FD_SET ((SOCKET) h, &wfds);
500 if (sought & (POLLPRI | POLLRDBAND))
502 requested |= FD_OOB;
503 FD_SET ((SOCKET) h, &xfds);
506 if (requested)
507 WSAEventSelect ((SOCKET) h, hEvent, requested);
509 else
511 /* Poll now. If we get an event, do not poll again. Also,
512 screen buffer handles are waitable, and they'll block until
513 a character is available. win32_compute_revents eliminates
514 bits for the "wrong" direction. */
515 pfd[i].revents = win32_compute_revents (h, &sought);
516 if (sought)
517 handle_array[nhandles++] = h;
518 if (pfd[i].revents)
519 timeout = 0;
523 if (select (0, &rfds, &wfds, &xfds, &tv0) > 0)
525 /* Do MsgWaitForMultipleObjects anyway to dispatch messages, but
526 no need to call select again. */
527 poll_again = FALSE;
528 wait_timeout = 0;
530 else
532 poll_again = TRUE;
533 if (timeout == INFTIM)
534 wait_timeout = INFINITE;
535 else
536 wait_timeout = timeout;
539 for (;;)
541 ret = MsgWaitForMultipleObjects (nhandles, handle_array, FALSE,
542 wait_timeout, QS_ALLINPUT);
544 if (ret == WAIT_OBJECT_0 + nhandles)
546 /* new input of some other kind */
547 BOOL bRet;
548 while ((bRet = PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) != 0)
550 TranslateMessage (&msg);
551 DispatchMessage (&msg);
554 else
555 break;
558 if (poll_again)
559 select (0, &rfds, &wfds, &xfds, &tv0);
561 /* Place a sentinel at the end of the array. */
562 handle_array[nhandles] = NULL;
563 nhandles = 1;
564 for (i = 0; i < nfd; i++)
566 int happened;
568 if (pfd[i].fd < 0)
569 continue;
570 if (!(pfd[i].events & (POLLIN | POLLRDNORM |
571 POLLOUT | POLLWRNORM | POLLWRBAND)))
572 continue;
574 h = (HANDLE) _get_osfhandle (pfd[i].fd);
575 if (h != handle_array[nhandles])
577 /* It's a socket. */
578 WSAEnumNetworkEvents ((SOCKET) h, NULL, &ev);
579 WSAEventSelect ((SOCKET) h, 0, 0);
581 /* If we're lucky, WSAEnumNetworkEvents already provided a way
582 to distinguish FD_READ and FD_ACCEPT; this saves a recv later. */
583 if (FD_ISSET ((SOCKET) h, &rfds)
584 && !(ev.lNetworkEvents & (FD_READ | FD_ACCEPT)))
585 ev.lNetworkEvents |= FD_READ | FD_ACCEPT;
586 if (FD_ISSET ((SOCKET) h, &wfds))
587 ev.lNetworkEvents |= FD_WRITE | FD_CONNECT;
588 if (FD_ISSET ((SOCKET) h, &xfds))
589 ev.lNetworkEvents |= FD_OOB;
591 happened = win32_compute_revents_socket ((SOCKET) h, pfd[i].events,
592 ev.lNetworkEvents);
594 else
596 /* Not a socket. */
597 int sought = pfd[i].events;
598 happened = win32_compute_revents (h, &sought);
599 nhandles++;
602 if ((pfd[i].revents |= happened) != 0)
603 rc++;
606 if (!rc && timeout == INFTIM)
608 SwitchToThread();
609 goto restart;
612 return rc;
613 #endif