On Wed, Jan 29, 2020 at 05:33:20PM +0100, Pavel Hrdina wrote: > On Tue, Jan 28, 2020 at 01:11:14PM +0000, Daniel P. Berrangé wrote: > > We need to be able to create event loop watches using the > > GSource API for sockets. GIOChannel is able todo this, but > > we don't want to use the GIOChannel APIs for reading/writing, > > and testing shows just using its GSource APIs is unreliable > > on Windows. > > > > This patch thus creates a standalone helper API for creating > > a GSource for a socket file descriptor. This impl is derived > > from code in QEMU's io/channel-watch.c file that was written > > by myself & Paolo Bonzini & thus under Red Hat copyright. > > > > Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx> > > --- > > build-aux/syntax-check.mk | 3 + > > src/util/Makefile.inc.am | 2 + > > src/util/vireventglibwatch.c | 248 +++++++++++++++++++++++++++++++++++ > > src/util/vireventglibwatch.h | 48 +++++++ > > 4 files changed, 301 insertions(+) > > create mode 100644 src/util/vireventglibwatch.c > > create mode 100644 src/util/vireventglibwatch.h > > > > diff --git a/src/util/vireventglibwatch.c b/src/util/vireventglibwatch.c > > new file mode 100644 > > index 0000000000..f7b087e2ec > > --- /dev/null > > +++ b/src/util/vireventglibwatch.c > > @@ -0,0 +1,248 @@ > > +/* > > + * vireventglibwatch.c: GSource impl for sockets > > + * > > + * Copyright (C) 2015-2020 Red Hat, Inc. > > + * > > + * 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 2.1 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/>. > > + */ > > + > > +#include <config.h> > > + > > +#include "vireventglibwatch.h" > > + > > +#ifndef WIN32 > > +typedef struct virEventGLibFDSource virEventGLibFDSource; > > +struct virEventGLibFDSource { > > + GSource parent; > > + GPollFD pollfd; > > + int fd; > > + GIOCondition condition; > > +}; > > + > > + > > +static gboolean > > +virEventGLibFDSourcePrepare(GSource *source G_GNUC_UNUSED, > > + gint *timeout) > > +{ > > + *timeout = -1; > > + > > + return FALSE; > > +} > > + > > + > > +static gboolean > > +virEventGLibFDSourceCheck(GSource *source) > > +{ > > + virEventGLibFDSource *ssource = (virEventGLibFDSource *)source; > > + > > + return ssource->pollfd.revents & ssource->condition; > > +} > > + > > + > > +static gboolean > > +virEventGLibFDSourceDispatch(GSource *source, > > + GSourceFunc callback, > > + gpointer user_data) > > +{ > > + virEventGLibSocketFunc func = (virEventGLibSocketFunc)callback; > > + virEventGLibFDSource *ssource = (virEventGLibFDSource *)source; > > + > > + return (*func)(ssource->fd, > > + ssource->pollfd.revents & ssource->condition, > > + user_data); > > +} > > + > > + > > +static void > > +virEventGLibFDSourceFinalize(GSource *source G_GNUC_UNUSED) > > +{ > > +} > > + > > + > > +GSourceFuncs virEventGLibFDSourceFuncs = { > > + .prepare = virEventGLibFDSourcePrepare, > > + .check = virEventGLibFDSourceCheck, > > + .dispatch = virEventGLibFDSourceDispatch, > > + .finalize = virEventGLibFDSourceFinalize > > +}; > > + > > + > > +GSource *virEventGLibCreateSocketWatch(int fd, > > + GIOCondition condition) > > +{ > > + GSource *source; > > + virEventGLibFDSource *ssource; > > + > > + source = g_source_new(&virEventGLibFDSourceFuncs, > > + sizeof(virEventGLibFDSource)); > > + ssource = (virEventGLibFDSource *)source; > > + > > + ssource->condition = condition; > > + ssource->fd = fd; > > + > > + ssource->pollfd.fd = fd; > > + ssource->pollfd.events = condition; > > + > > + g_source_add_poll(source, &ssource->pollfd); > > + > > + return source; > > +} > > + > > +#else /* WIN32 */ > > + > > +# define WIN32_LEAN_AND_MEAN > > +# include <winsock2.h> > > + > > +typedef struct virEventGLibSocketSource virEventGLibSocketSource; > > +struct virEventGLibSocketSource { > > + GSource parent; > > + GPollFD pollfd; > > + int fd; > > + SOCKET socket; > > + HANDLE event; > > + int revents; > > + GIOCondition condition; > > +}; > > + > > + > > +static gboolean > > +virEventGLibSocketSourcePrepare(GSource *source G_GNUC_UNUSED, > > + gint *timeout) > > +{ > > + *timeout = -1; > > + > > + return FALSE; > > +} > > + > > + > > +/* > > + * NB, this impl only works when the socket is in non-blocking > > + * mode on Win32 > > + */ > > +static gboolean > > +virEventGLibSocketSourceCheck(GSource *source) > > +{ > > + static struct timeval tv0; > > + > > + virEventGLibSocketSource *ssource = (virEventGLibSocketSource *)source; > > + WSANETWORKEVENTS ev; > > + fd_set rfds, wfds, xfds; > > + > > + if (!ssource->condition) > > + return 0; > > + > > + WSAEnumNetworkEvents(ssource->socket, ssource->event, &ev); > > + > > + FD_ZERO(&rfds); > > + FD_ZERO(&wfds); > > + FD_ZERO(&xfds); > > + if (ssource->condition & G_IO_IN) > > + FD_SET(ssource->socket, &rfds); > > + if (ssource->condition & G_IO_OUT) > > + FD_SET(ssource->socket, &wfds); > > + if (ssource->condition & G_IO_PRI) > > + FD_SET(ssource->socket, &xfds); > > + > > + ssource->revents = 0; > > + if (select(0, &rfds, &wfds, &xfds, &tv0) == 0) > > + return 0; > > + > > + if (FD_ISSET(ssource->socket, &rfds)) > > + ssource->revents |= G_IO_IN; > > + > > + if (FD_ISSET(ssource->socket, &wfds)) > > + ssource->revents |= G_IO_OUT; > > + > > + if (FD_ISSET(ssource->socket, &xfds)) > > + ssource->revents |= G_IO_PRI; > > + > > + return ssource->revents; > > +} > > + > > + > > +static gboolean > > +virEventGLibSocketSourceDispatch(GSource *source, > > + GSourceFunc callback, > > + gpointer user_data) > > +{ > > + virEventGLibSocketFunc func = (virEventGLibSocketFunc)callback; > > + virEventGLibSocketSource *ssource = (virEventGLibSocketSource *)source; > > + > > + return (*func)(ssource->fd, ssource->revents, user_data); > > +} > > + > > + > > +static void > > +virEventGLibSocketSourceFinalize(GSource *source) > > +{ > > + virEventGLibSocketSource *ssource = (virEventGLibSocketSource *)source; > > + > > + WSAEventSelect(ssource->socket, NULL, 0); > > +} > > + > > + > > +GSourceFuncs virEventGLibSocketSourceFuncs = { > > + .prepare = virEventGLibSocketSourcePrepare, > > + .check = virEventGLibSocketSourceCheck, > > + .dispatch = virEventGLibSocketSourceDispatch, > > + .finalize = virEventGLibSocketSourceFinalize > > +}; > > + > > + > > +GSource *virEventGLibCreateSocketWatch(int fd, > > + GIOCondition condition) > > +{ > > + GSource *source; > > + virEventGLibSocketSource *ssource; > > + > > + source = g_source_new(&virEventGLibSocketSourceFuncs, > > + sizeof(virEventGLibSocketSource)); > > + ssource = (virEventGLibSocketSource *)source; > > + > > + ssource->condition = condition; > > + ssource->fd = fd; > > + ssource->socket = _get_osfhandle(fd); > > + ssource->event = CreateEvent(NULL, FALSE, FALSE, NULL); > > Based on going through QEMU code and windows documentation it looks > like we have to free the event using CloseHandle(). > > QEMU is doing it in io/channel.c in qio_channel_finalize() which is > probably called by unrefing ssource->ioc in > qio_channel_fd_pair_source_finalize(). > > That would mean we have to call CloseHandle() in > virEventGLibSocketSourceFinalize() to make sure we will not leak any > resources. Yes, you are correct. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
