}
/*
- * 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;
}
+
+ size_t getpagesize(void)
+ {
+ SYSTEM_INFO system_info;
+
+ GetSystemInfo(&system_info);
+ return system_info.dwPageSize;
+ }
+
+ void os_mem_prealloc(int fd, char *area, size_t memory)
+ {
+ int i;
+ size_t pagesize = getpagesize();
+
+ memory = (memory + pagesize - 1) & -pagesize;
+ for (i = 0; i < memory / pagesize; i++) {
+ memset(area + pagesize * i, 0, 1);
+ }
+ }
projects / sdk / emulator / qemu.git / commitdiff