The libvirt-glib project has provided a GMainContext based
event loop impl for applications. This imports it and sets
it up for use by libvirt as the primary event loop. This
remains a private impl detail of libvirt.
IOW, applications must *NOT* assume that a call to
"virEventRegisterDefaultImpl" results in a GLib based
event loop. They should continue to use the libvirt-glib
API gvir_event_register() if they explicitly want to
guarantee a GLib event loop.
This follows the general principle that the libvirt public
API should not expose the fact that GLib is being used
internally.
Signed-off-by: Daniel P. Berrangé <berrange@xxxxxxxxxx>
---
build-aux/syntax-check.mk | 2 +-
src/libvirt_private.syms | 5 +
src/libvirt_probes.d | 14 ++
src/util/Makefile.inc.am | 2 +
src/util/vireventglib.c | 499 ++++++++++++++++++++++++++++++++++++++
src/util/vireventglib.h | 28 +++
6 files changed, 549 insertions(+), 1 deletion(-)
create mode 100644 src/util/vireventglib.c
create mode 100644 src/util/vireventglib.h
diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk
index d43fa501aa..3a36c3bece 100644
--- a/build-aux/syntax-check.mk
+++ b/build-aux/syntax-check.mk
@@ -2176,7 +2176,7 @@ exclude_file_name_regexp--sc_avoid_write = \
exclude_file_name_regexp--sc_bindtextdomain = .*
-exclude_file_name_regexp--sc_gettext_init = ^((tests|examples)/|tools/virt-login-shell.c)
+exclude_file_name_regexp--sc_gettext_init = ^((tests|examples)/|tools/virt-login-shell.c|src/util/vireventglib\.c)
exclude_file_name_regexp--sc_copyright_format = \
^build-aux/syntax-check\.mk$$
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index ddf1fae71f..417ee05a24 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1933,6 +1933,11 @@ virSetErrorLogPriorityFunc;
virStrerror;
+# util/vireventglib.h
+virEventGLibRegister;
+virEventGLibRunOnce;
+
+
# util/vireventpoll.h
virEventPollAddHandle;
virEventPollAddTimeout;
diff --git a/src/libvirt_probes.d b/src/libvirt_probes.d
index 2a8d600c0e..a1edb4116d 100644
--- a/src/libvirt_probes.d
+++ b/src/libvirt_probes.d
@@ -15,6 +15,20 @@ provider libvirt {
probe event_poll_run(int nfds, int timeout);
+ # file: src/util/vireventglib.c
+ # prefix: event_glib
+ probe event_glib_add_handle(int watch, int fd, int events, void *cb, void *opaque, void *ff);
+ probe event_glib_update_handle(int watch, int events);
+ probe event_glib_remove_handle(int watch);
+ probe event_glib_remove_handle_idle(int watch, void *ff, void *opaque);
+ probe event_glib_dispatch_handle(int watch, int events, void *cb, void *opaque);
+
+ probe event_glib_add_timeout(int timer, int frequency, void *cb, void *opaque, void *ff);
+ probe event_glib_update_timeout(int timer, int frequency);
+ probe event_glib_remove_timeout(int timer);
+ probe event_glib_remove_timeout_idle(int timer, void *ff, void *opaque);
+ probe event_glib_dispatch_timeout(int timer, void *cb, void *opaque);
+
# file: src/util/virdbus.c
# prefix: dbus
probe dbus_method_call(const char *interface, const char *member, const char *object, const char *destination);
diff --git a/src/util/Makefile.inc.am b/src/util/Makefile.inc.am
index a51cba736b..3a42543a5e 100644
--- a/src/util/Makefile.inc.am
+++ b/src/util/Makefile.inc.am
@@ -61,6 +61,8 @@ UTIL_SOURCES = \
util/virerrorpriv.h \
util/virevent.c \
util/virevent.h \
+ util/vireventglib.c \
+ util/vireventglib.h \
util/vireventglibwatch.c \
util/vireventglibwatch.h \
util/vireventpoll.c \
diff --git a/src/util/vireventglib.c b/src/util/vireventglib.c
new file mode 100644
index 0000000000..803332a6f8
--- /dev/null
+++ b/src/util/vireventglib.c
@@ -0,0 +1,499 @@
+/*
+ * vireventglib.c: GMainContext based event loop
+ *
+ * Copyright (C) 2008 Daniel P. Berrange
+ * Copyright (C) 2010-2019 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 <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "vireventglib.h"
+#include "vireventglibwatch.h"
+#include "virerror.h"
+#include "virlog.h"
+#include "virprobe.h"
+
+#ifdef G_OS_WIN32
+# include <io.h>
+#endif
+
+#define VIR_FROM_THIS VIR_FROM_EVENT
+
+VIR_LOG_INIT("util.eventglib");
+
+struct virEventGLibHandle
+{
+ int watch;
+ int fd;
+ int events;
+ int removed;
+ guint source;
+ virEventHandleCallback cb;
+ void *opaque;
+ virFreeCallback ff;
+};
+
+struct virEventGLibTimeout
+{
+ int timer;
+ int interval;
+ int removed;
+ guint source;
+ virEventTimeoutCallback cb;
+ void *opaque;
+ virFreeCallback ff;
+};
+
+static GMutex *eventlock;
+
+static int nextwatch = 1;
+static GPtrArray *handles;
+
+static int nexttimer = 1;
+static GPtrArray *timeouts;
+
+static GIOCondition
+virEventGLibEventsToCondition(int events)
+{
+ GIOCondition cond = 0;
+ if (events & VIR_EVENT_HANDLE_READABLE)
+ cond |= G_IO_IN;
+ if (events & VIR_EVENT_HANDLE_WRITABLE)
+ cond |= G_IO_OUT;
+ if (events & VIR_EVENT_HANDLE_ERROR)
+ cond |= G_IO_ERR;
+ if (events & VIR_EVENT_HANDLE_HANGUP)
+ cond |= G_IO_HUP;
+ return cond;
+}
+
+static int
+virEventGLibConditionToEvents(GIOCondition cond)
+{
+ int events = 0;
+ if (cond & G_IO_IN)
+ events |= VIR_EVENT_HANDLE_READABLE;
+ if (cond & G_IO_OUT)
+ events |= VIR_EVENT_HANDLE_WRITABLE;
+ if (cond & G_IO_ERR)
+ events |= VIR_EVENT_HANDLE_ERROR;
+ if (cond & G_IO_NVAL) /* Treat NVAL as error, since libvirt doesn't distinguish */
+ events |= VIR_EVENT_HANDLE_ERROR;
+ if (cond & G_IO_HUP)
+ events |= VIR_EVENT_HANDLE_HANGUP;
+ return events;
+}
+
+static gboolean
+virEventGLibHandleDispatch(int fd G_GNUC_UNUSED,
+ GIOCondition condition,
+ gpointer opaque)
+{
+ struct virEventGLibHandle *data = opaque;
+ int events = virEventGLibConditionToEvents(condition);
+
+ VIR_DEBUG("Dispatch handler data=%p watch=%d fd=%d events=%d opaque=%p",
+ data, data->watch, data->fd, events, data->opaque);
+
+ PROBE(EVENT_GLIB_DISPATCH_HANDLE,
+ "watch=%d events=%d cb=%p opaque=%p",
+ data->watch, events, data->cb, data->opaque);
+
+ (data->cb)(data->watch, data->fd, events, data->opaque);
+
+ return TRUE;
+}
+
+
+static int
+virEventGLibHandleAdd(int fd,
+ int events,
+ virEventHandleCallback cb,
+ void *opaque,
+ virFreeCallback ff)
+{
+ struct virEventGLibHandle *data;
+ GIOCondition cond = virEventGLibEventsToCondition(events);
+ int ret;
+
+ g_mutex_lock(eventlock);
+
+ data = g_new0(struct virEventGLibHandle, 1);
+
+ data->watch = nextwatch++;
+ data->fd = fd;
+ data->events = events;
+ data->cb = cb;
+ data->opaque = opaque;
+ data->ff = ff;
+
+ VIR_DEBUG("Add handle data=%p watch=%d fd=%d events=%d opaque=%p",
+ data, data->watch, data->fd, events, data->opaque);
+
+ if (events != 0) {
+ data->source = virEventGLibAddSocketWatch(
+ fd, cond, NULL, virEventGLibHandleDispatch, data, NULL);
+ }
+
+ g_ptr_array_add(handles, data);
+
+ ret = data->watch;
+
+ PROBE(EVENT_GLIB_ADD_HANDLE,
+ "watch=%d fd=%d events=%d cb=%p opaque=%p ff=%p",
+ ret, fd, events, cb, opaque, ff);
+ g_mutex_unlock(eventlock);
+
+ return ret;
+}
+
+static struct virEventGLibHandle *
+virEventGLibHandleFind(int watch)
+{
+ guint i;
+
+ for (i = 0; i < handles->len; i++) {
+ struct virEventGLibHandle *h = g_ptr_array_index(handles, i);
+
+ if (h == NULL) {
+ g_warn_if_reached();
+ continue;
+ }
+
+ if ((h->watch == watch) && !h->removed)
+ return h;
+ }
+
+ return NULL;
+}
+
+static void
+virEventGLibHandleUpdate(int watch,
+ int events)
+{
+ struct virEventGLibHandle *data;
+
+ PROBE(EVENT_GLIB_UPDATE_HANDLE,
+ "watch=%d events=%d",
+ watch, events);
+ g_mutex_lock(eventlock);
+
+ data = virEventGLibHandleFind(watch);
+ if (!data) {
+ VIR_DEBUG("Update for missing handle watch=%d", watch);
+ goto cleanup;
+ }
+
+ VIR_DEBUG("Update handle data=%p watch=%d fd=%d events=%d",
+ data, watch, data->fd, events);
+
+ if (events != 0) {
+ GIOCondition cond = virEventGLibEventsToCondition(events);
+ if (events == data->events)
+ goto cleanup;
+
+ if (data->source != 0) {
+ VIR_DEBUG("Removed old handle watch=%d", data->source);
+ g_source_remove(data->source);
+ }
+
+ data->source = virEventGLibAddSocketWatch(
+ data->fd, cond, NULL, virEventGLibHandleDispatch, data, NULL);
+
+ data->events = events;
+ VIR_DEBUG("Added new handle watch=%d", data->source);
+ } else {
+ if (data->source == 0)
+ goto cleanup;
+
+ VIR_DEBUG("Removed old handle watch=%d", data->source);
+ g_source_remove(data->source);
+ data->source = 0;
+ data->events = 0;
+ }
+
+ cleanup:
+ g_mutex_unlock(eventlock);
+}
+
+static gboolean
+virEventGLibHandleRemoveIdle(gpointer data)
+{
+ struct virEventGLibHandle *h = data;
+
+ PROBE(EVENT_GLIB_REMOVE_HANDLE_IDLE,
+ "watch=%d ff=%p opaque=%p",
+ h->watch, h->ff, h->opaque);
+ if (h->ff)
+ (h->ff)(h->opaque);
+
+ g_mutex_lock(eventlock);
+ g_ptr_array_remove_fast(handles, h);
+ g_mutex_unlock(eventlock);
+
+ return FALSE;
+}
+
+static int
+virEventGLibHandleRemove(int watch)
+{
+ struct virEventGLibHandle *data;
+ int ret = -1;
+
+ PROBE(EVENT_GLIB_REMOVE_HANDLE,
+ "watch=%d",
+ watch);
+ g_mutex_lock(eventlock);
+
+ data = virEventGLibHandleFind(watch);
+ if (!data) {
+ VIR_DEBUG("Remove of missing handle watch=%d", watch);
+ goto cleanup;
+ }
+
+ VIR_DEBUG("Remove handle data=%p watch=%d fd=%d",
+ data, watch, data->fd);
+
+ if (data->source != 0) {
+ g_source_remove(data->source);
+ data->source = 0;
+ data->events = 0;
+ }
+
+ /* since the actual watch deletion is done asynchronously, a handleUpdate call may
+ * reschedule the watch before it's fully deleted, that's why we need to mark it as
+ * 'removed' to prevent reuse
+ */
+ data->removed = TRUE;
+ g_idle_add(virEventGLibHandleRemoveIdle, data);
+
+ ret = 0;
+
+ cleanup:
+ g_mutex_unlock(eventlock);
+ return ret;
+}
+
+
+static gboolean
+virEventGLibTimeoutDispatch(void *opaque)
+{
+ struct virEventGLibTimeout *data = opaque;
+
+ VIR_DEBUG("Dispatch timeout data=%p cb=%p timer=%d opaque=%p",
+ data, data->cb, data->timer, data->opaque);
+
+ PROBE(EVENT_GLIB_DISPATCH_TIMEOUT,
+ "timer=%d cb=%p opaque=%p",
+ data->timer, data->cb, data->opaque);
+ (data->cb)(data->timer, data->opaque);
+
+ return TRUE;
+}
+
+static int
+virEventGLibTimeoutAdd(int interval,
+ virEventTimeoutCallback cb,
+ void *opaque,
+ virFreeCallback ff)
+{
+ struct virEventGLibTimeout *data;
+ int ret;
+
+ g_mutex_lock(eventlock);
+
+ data = g_new0(struct virEventGLibTimeout, 1);
+ data->timer = nexttimer++;
+ data->interval = interval;
+ data->cb = cb;
+ data->opaque = opaque;
+ data->ff = ff;
+ if (interval >= 0)
+ data->source = g_timeout_add(interval,
+ virEventGLibTimeoutDispatch,
+ data);
+
+ g_ptr_array_add(timeouts, data);
+
+ VIR_DEBUG("Add timeout data=%p interval=%d ms cb=%p opaque=%p timer=%d",
+ data, interval, cb, opaque, data->timer);
+
+ ret = data->timer;
+
+ PROBE(EVENT_GLIB_ADD_TIMEOUT,
+ "timer=%d interval=%d cb=%p opaque=%p ff=%p",
+ ret, interval, cb, opaque, ff);
+ g_mutex_unlock(eventlock);
+
+ return ret;
+}
+
+
+static struct virEventGLibTimeout *
+virEventGLibTimeoutFind(int timer)
+{
+ guint i;
+
+ g_return_val_if_fail(timeouts != NULL, NULL);
+
+ for (i = 0; i < timeouts->len; i++) {
+ struct virEventGLibTimeout *t = g_ptr_array_index(timeouts, i);
+
+ if (t == NULL) {
+ g_warn_if_reached();
+ continue;
+ }
+
+ if ((t->timer == timer) && !t->removed)
+ return t;
+ }
+
+ return NULL;
+}
+
+
+static void
+virEventGLibTimeoutUpdate(int timer,
+ int interval)
+{
+ struct virEventGLibTimeout *data;
+
+ PROBE(EVENT_GLIB_UPDATE_TIMEOUT,
+ "timer=%d interval=%d",
+ timer, interval);
+ g_mutex_lock(eventlock);
+
+ data = virEventGLibTimeoutFind(timer);
+ if (!data) {
+ VIR_DEBUG("Update of missing timeout timer=%d", timer);
+ goto cleanup;
+ }
+
+ VIR_DEBUG("Update timeout data=%p timer=%d interval=%d ms", data, timer, interval);
+
+ if (interval >= 0) {
+ if (data->source != 0)
+ g_source_remove(data->source);
+
+ data->interval = interval;
+ data->source = g_timeout_add(data->interval,
+ virEventGLibTimeoutDispatch,
+ data);
+ } else {
+ if (data->source == 0)
+ goto cleanup;
+
+ g_source_remove(data->source);
+ data->source = 0;
+ }
+
+ cleanup:
+ g_mutex_unlock(eventlock);
+}
+
+static gboolean
+virEventGLibTimeoutRemoveIdle(gpointer data)
+{
+ struct virEventGLibTimeout *t = data;
+
+ PROBE(EVENT_GLIB_REMOVE_TIMEOUT_IDLE,
+ "timer=%d ff=%p opaque=%p",
+ t->timer, t->ff, t->opaque);
+
+ if (t->ff)
+ (t->ff)(t->opaque);
+
+ g_mutex_lock(eventlock);
+ g_ptr_array_remove_fast(timeouts, t);
+ g_mutex_unlock(eventlock);
+
+ return FALSE;
+}
+
+static int
+virEventGLibTimeoutRemove(int timer)
+{
+ struct virEventGLibTimeout *data;
+ int ret = -1;
+
+ PROBE(EVENT_GLIB_REMOVE_TIMEOUT,
+ "timer=%d",
+ timer);
+ g_mutex_lock(eventlock);
+
+ data = virEventGLibTimeoutFind(timer);
+ if (!data) {
+ VIR_DEBUG("Remove of missing timeout timer=%d", timer);
+ goto cleanup;
+ }
+
+ VIR_DEBUG("Remove timeout data=%p timer=%d",
+ data, timer);
+
+ if (data->source != 0) {
+ g_source_remove(data->source);
+ data->source = 0;
+ }
+
+ /* since the actual timeout deletion is done asynchronously, a timeoutUpdate call may
+ * reschedule the timeout before it's fully deleted, that's why we need to mark it as
+ * 'removed' to prevent reuse
+ */
+ data->removed = TRUE;
+ g_idle_add(virEventGLibTimeoutRemoveIdle, data);
+
+ ret = 0;
+
+ cleanup:
+ g_mutex_unlock(eventlock);
+ return ret;
+}
+
+
+static gpointer virEventGLibRegisterOnce(gpointer data G_GNUC_UNUSED)
+{
+ eventlock = g_new0(GMutex, 1);
+ timeouts = g_ptr_array_new_with_free_func(g_free);
+ handles = g_ptr_array_new_with_free_func(g_free);
+ virEventRegisterImpl(virEventGLibHandleAdd,
+ virEventGLibHandleUpdate,
+ virEventGLibHandleRemove,
+ virEventGLibTimeoutAdd,
+ virEventGLibTimeoutUpdate,
+ virEventGLibTimeoutRemove);
+ return NULL;
+}
+
+
+void virEventGLibRegister(void)
+{
+ static GOnce once = G_ONCE_INIT;
+
+ g_once(&once, virEventGLibRegisterOnce, NULL);
+}
+
+
+int virEventGLibRunOnce(void)
+{
+ g_main_context_iteration(NULL, TRUE);
+
+ return 0;
+}
diff --git a/src/util/vireventglib.h b/src/util/vireventglib.h
new file mode 100644
index 0000000000..ef68abaa20
--- /dev/null
+++ b/src/util/vireventglib.h
@@ -0,0 +1,28 @@
+/*
+ * vireventglib.h: GMainContext based event loop
+ *
+ * Copyright (C) 2008 Daniel P. Berrange
+ * Copyright (C) 2010-2019 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/>.
+ */
+
+#pragma once
+
+#include "internal.h"
+
+void virEventGLibRegister(void);
+
+int virEventGLibRunOnce(void);
--
2.24.1
