diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/oslib-win32.c | 252 |
1 files changed, 174 insertions, 78 deletions
diff --git a/util/oslib-win32.c b/util/oslib-win32.c index 69552f7ec3..157f10fab2 100644 --- a/util/oslib-win32.c +++ b/util/oslib-win32.c @@ -24,6 +24,10 @@ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. + * + * The implementation of g_poll (functions poll_rest, g_poll) at the end of + * this file are based on code from GNOME glib-2 and use a different license, + * see the license comment there. */ #include <windows.h> #include <glib.h> @@ -138,7 +142,7 @@ int inet_aton(const char *cp, struct in_addr *ia) { uint32_t addr = inet_addr(cp); if (addr == 0xffffffff) { - return 0; + return 0; } ia->s_addr = addr; return 1; @@ -240,113 +244,205 @@ char *qemu_get_exec_dir(void) } /* - * g_poll has a problem on Windows when using - * timeouts < 10ms, in glib/gpoll.c: + * The original implementation of g_poll from glib has a problem on Windows + * when using timeouts < 10 ms. * - * // If not, and we have a significant timeout, poll again with - * // timeout then. Note that this will return indication for only - * // one event, or only for messages. We ignore timeouts less than - * // ten milliseconds as they are mostly pointless on Windows, the - * // MsgWaitForMultipleObjectsEx() call will timeout right away - * // anyway. + * Whenever g_poll is called with timeout < 10 ms, it does a quick poll instead + * of wait. This causes significant performance degradation of QEMU. * - * if (retval == 0 && (timeout == INFINITE || timeout >= 10)) - * retval = poll_rest (poll_msgs, handles, nhandles, fds, nfds, timeout); + * The following code is a copy of the original code from glib/gpoll.c + * (glib commit 20f4d1820b8d4d0fc4447188e33efffd6d4a88d8 from 2014-02-19). + * Some debug code was removed and the code was reformatted. + * All other code modifications are marked with 'QEMU'. + */ + +/* + * gpoll.c: poll(2) abstraction + * Copyright 1998 Owen Taylor + * Copyright 2008 Red Hat, Inc. * - * So whenever g_poll is called with timeout < 10ms it does - * a quick poll instead of wait, this causes significant performance - * degradation of QEMU, thus we should use WaitForMultipleObjectsEx - * directly + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. */ -gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout) + +static int poll_rest(gboolean poll_msgs, HANDLE *handles, gint nhandles, + GPollFD *fds, guint nfds, gint timeout) { - guint i; - HANDLE handles[MAXIMUM_WAIT_OBJECTS]; - gint nhandles = 0; - int num_completed = 0; + DWORD ready; + GPollFD *f; + int recursed_result; - for (i = 0; i < nfds; i++) { - gint j; + if (poll_msgs) { + /* Wait for either messages or handles + * -> Use MsgWaitForMultipleObjectsEx + */ + ready = MsgWaitForMultipleObjectsEx(nhandles, handles, timeout, + QS_ALLINPUT, MWMO_ALERTABLE); - if (fds[i].fd <= 0) { - continue; + if (ready == WAIT_FAILED) { + gchar *emsg = g_win32_error_message(GetLastError()); + g_warning("MsgWaitForMultipleObjectsEx failed: %s", emsg); + g_free(emsg); } - - /* don't add same handle several times + } else if (nhandles == 0) { + /* No handles to wait for, just the timeout */ + if (timeout == INFINITE) { + ready = WAIT_FAILED; + } else { + SleepEx(timeout, TRUE); + ready = WAIT_TIMEOUT; + } + } else { + /* Wait for just handles + * -> Use WaitForMultipleObjectsEx */ - for (j = 0; j < nhandles; j++) { - if (handles[j] == (HANDLE)fds[i].fd) { - break; - } + ready = + WaitForMultipleObjectsEx(nhandles, handles, FALSE, timeout, TRUE); + if (ready == WAIT_FAILED) { + gchar *emsg = g_win32_error_message(GetLastError()); + g_warning("WaitForMultipleObjectsEx failed: %s", emsg); + g_free(emsg); } + } - if (j == nhandles) { - if (nhandles == MAXIMUM_WAIT_OBJECTS) { - fprintf(stderr, "Too many handles to wait for!\n"); - break; - } else { - handles[nhandles++] = (HANDLE)fds[i].fd; + if (ready == WAIT_FAILED) { + return -1; + } else if (ready == WAIT_TIMEOUT || ready == WAIT_IO_COMPLETION) { + return 0; + } else if (poll_msgs && ready == WAIT_OBJECT_0 + nhandles) { + for (f = fds; f < &fds[nfds]; ++f) { + if (f->fd == G_WIN32_MSG_HANDLE && f->events & G_IO_IN) { + f->revents |= G_IO_IN; } } - } - for (i = 0; i < nfds; ++i) { - fds[i].revents = 0; - } + /* If we have a timeout, or no handles to poll, be satisfied + * with just noticing we have messages waiting. + */ + if (timeout != 0 || nhandles == 0) { + return 1; + } - if (timeout == -1) { - timeout = INFINITE; - } + /* If no timeout and handles to poll, recurse to poll them, + * too. + */ + recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0); + return (recursed_result == -1) ? -1 : 1 + recursed_result; + } else if (/* QEMU: removed the following unneeded statement which causes + * a compiler warning: ready >= WAIT_OBJECT_0 && */ + ready < WAIT_OBJECT_0 + nhandles) { + for (f = fds; f < &fds[nfds]; ++f) { + if ((HANDLE) f->fd == handles[ready - WAIT_OBJECT_0]) { + f->revents = f->events; + } + } - if (nhandles == 0) { - if (timeout == INFINITE) { - return -1; - } else { - SleepEx(timeout, TRUE); - return 0; + /* If no timeout and polling several handles, recurse to poll + * the rest of them. + */ + if (timeout == 0 && nhandles > 1) { + /* Remove the handle that fired */ + int i; + if (ready < nhandles - 1) { + for (i = ready - WAIT_OBJECT_0 + 1; i < nhandles; i++) { + handles[i-1] = handles[i]; + } + } + nhandles--; + recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0); + return (recursed_result == -1) ? -1 : 1 + recursed_result; } + return 1; } - while (1) { - DWORD res; - gint j; - - res = WaitForMultipleObjectsEx(nhandles, handles, FALSE, - timeout, TRUE); + return 0; +} - if (res == WAIT_FAILED) { - for (i = 0; i < nfds; ++i) { - fds[i].revents = 0; +gint g_poll(GPollFD *fds, guint nfds, gint timeout) +{ + HANDLE handles[MAXIMUM_WAIT_OBJECTS]; + gboolean poll_msgs = FALSE; + GPollFD *f; + gint nhandles = 0; + int retval; + + for (f = fds; f < &fds[nfds]; ++f) { + if (f->fd == G_WIN32_MSG_HANDLE && (f->events & G_IO_IN)) { + poll_msgs = TRUE; + } else if (f->fd > 0) { + /* Don't add the same handle several times into the array, as + * docs say that is not allowed, even if it actually does seem + * to work. + */ + gint i; + + for (i = 0; i < nhandles; i++) { + if (handles[i] == (HANDLE) f->fd) { + break; + } } - return -1; - } else if ((res == WAIT_TIMEOUT) || (res == WAIT_IO_COMPLETION) || - ((int)res < (int)WAIT_OBJECT_0) || - (res >= (WAIT_OBJECT_0 + nhandles))) { - break; - } - - for (i = 0; i < nfds; ++i) { - if (handles[res - WAIT_OBJECT_0] == (HANDLE)fds[i].fd) { - fds[i].revents = fds[i].events; + if (i == nhandles) { + if (nhandles == MAXIMUM_WAIT_OBJECTS) { + g_warning("Too many handles to wait for!\n"); + break; + } else { + handles[nhandles++] = (HANDLE) f->fd; + } } } + } - ++num_completed; + for (f = fds; f < &fds[nfds]; ++f) { + f->revents = 0; + } - if (nhandles <= 1) { - break; - } + if (timeout == -1) { + timeout = INFINITE; + } - /* poll the rest of the handles + /* Polling for several things? */ + if (nhandles > 1 || (nhandles > 0 && poll_msgs)) { + /* First check if one or several of them are immediately + * available + */ + retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, 0); + + /* If not, and we have a significant timeout, poll again with + * timeout then. Note that this will return indication for only + * one event, or only for messages. We ignore timeouts less than + * ten milliseconds as they are mostly pointless on Windows, the + * MsgWaitForMultipleObjectsEx() call will timeout right away + * anyway. + * + * Modification for QEMU: replaced timeout >= 10 by timeout > 0. */ - for (j = res - WAIT_OBJECT_0 + 1; j < nhandles; j++) { - handles[j - 1] = handles[j]; + if (retval == 0 && (timeout == INFINITE || timeout > 0)) { + retval = poll_rest(poll_msgs, handles, nhandles, + fds, nfds, timeout); } - --nhandles; + } else { + /* Just polling for one thing, so no need to check first if + * available immediately + */ + retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, timeout); + } - timeout = 0; + if (retval == -1) { + for (f = fds; f < &fds[nfds]; ++f) { + f->revents = 0; + } } - return num_completed; + return retval; } |