[Spice-devel] [qxl] xspice: Adjust to X.org 1.19 changes

[Christophe Fergeau]

In newer X.org versions, it's no longer supported to modify the set of
FDs passed to a BlockHandler method to get notified when the FD has data
to be read. This was limited anyway as we could only get read events
this way, and had to do our own polling to get notified about socket
writeability.

Starting from xserver 1.19, the supported way of doing this is to use
the SetNotifyFd/RemoveNotifyFd API, which is actually a much better way
as it matches very well the 'watch' API spice-server expects Xspice to
implement.

This commit switches to that new API, which removes the need for
RegisterBlockAndWakeupHandlers().
---
I've lightly (xeyes/rxvt) tested this on f25, and tested this still builds on
f24.
This should fix the issues Hans mentioned in
https://lists.freedesktop.org/archives/spice-devel/2016-October/032501.html


 configure.ac             |  5 ---
 src/spiceqxl_main_loop.c | 90 ++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 84 insertions(+), 11 deletions(-)

diff --git a/configure.ac b/configure.ac
index e865e75..b737d0d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -68,8 +68,6 @@ PKG_CHECK_EXISTS(xfont2,
 
 # Obtain compiler/linker options for the driver dependencies
 PKG_CHECK_MODULES(XORG, [xorg-server >= 1.0.99.901] xproto fontsproto $xfont_pc $REQUIRED_MODULES)
-# Check for xorg 1.19 as XSpice is currently not working with it
-PKG_CHECK_EXISTS([xorg-server >= 1.18.99], [has_xorg119=yes])
 
 save_CFLAGS="$CFLAGS"
 CFLAGS="$XORG_CFLAGS"
@@ -141,9 +139,6 @@ if test "x$enable_xspice" = "xyes"; then
         AC_SUBST(SPICE_LIBS)
     ],
     )
-    if test x"${enable_xspice}" = "xyes" && test x"${has_xorg119}" = "xyes"; then
-        AC_MSG_ERROR("XSpice cannot currently work against X.Org 1.19")
-    fi
 else
     enable_xspice=no
 fi
diff --git a/src/spiceqxl_main_loop.c b/src/spiceqxl_main_loop.c
index 49b715a..81bc418 100644
--- a/src/spiceqxl_main_loop.c
+++ b/src/spiceqxl_main_loop.c
@@ -193,6 +193,7 @@ static void timer_remove(SpiceTimer *timer)
     free(timer);
 }
 
+#if GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) < 23
 struct SpiceWatch {
     RingItem link;
     int fd;
@@ -236,11 +237,6 @@ static void watch_remove(SpiceWatch *watch)
     watch_count--;
 }
 
-static void channel_event(int event, SpiceChannelEventInfo *info)
-{
-    NOT_IMPLEMENTED
-}
-
 static int set_watch_fds(fd_set *rfds, fd_set *wfds)
 {
     SpiceWatch *watch;
@@ -276,7 +272,7 @@ static void xspice_block_handler(pointer data, OSTimePtr timeout, pointer readma
 /*
  * xserver only calls wakeup_handler with the read fd_set, so we
  * must either patch it or do a polling select ourselves, this is the
- * later approach. Since we are already doing a polling select, we
+ * latter approach. Since we are already doing a polling select, we
  * already select on all (we could avoid selecting on the read since
  * that *is* actually taken care of by the wakeup handler).
  */
@@ -338,9 +334,88 @@ static void xspice_wakeup_handler(pointer data, int nfds, pointer readmask)
     select_and_check_watches();
 }
 
+#else /* GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) < 23 */
+
+struct SpiceWatch {
+    int fd;
+    int event_mask;
+    SpiceWatchFunc func;
+    void *opaque;
+};
+
+static void watch_fd_notified(int fd, int xevents, void *data)
+{
+    SpiceWatch *watch = (SpiceWatch *)data;
+
+    if ((watch->event_mask & SPICE_WATCH_EVENT_READ) && (xevents & X_NOTIFY_READ)) {
+        watch->func(watch->fd, SPICE_WATCH_EVENT_READ, watch->opaque);
+    }
+
+    if ((watch->event_mask & SPICE_WATCH_EVENT_WRITE) && (xevents & X_NOTIFY_WRITE)) {
+        watch->func(watch->fd, SPICE_WATCH_EVENT_WRITE, watch->opaque);
+    }
+}
+
+static int watch_update_mask2(SpiceWatch *watch, int event_mask)
+{
+    SetNotifyFd(watch->fd, NULL, X_NOTIFY_NONE, NULL);
+    watch->event_mask = 0;
+
+    if (event_mask & SPICE_WATCH_EVENT_READ) {
+        SetNotifyFd(watch->fd, watch_fd_notified, X_NOTIFY_READ, watch);
+    } else if (event_mask & SPICE_WATCH_EVENT_READ) {
+        SetNotifyFd(watch->fd, watch_fd_notified, X_NOTIFY_WRITE, watch);
+    } else {
+        DPRINTF(0, "Unexpected watch event_mask: %i", event_mask);
+        return -1;
+    }
+    watch->event_mask = event_mask;
+
+    return 0;
+}
+
+static SpiceWatch *watch_add(int fd, int event_mask, SpiceWatchFunc func, void *opaque)
+{
+    SpiceWatch *watch = malloc(sizeof(SpiceWatch));
+
+    DPRINTF(0, "adding %p, fd=%d", watch, fd);
+
+    watch->fd = fd;
+    watch->func = func;
+    watch->opaque = opaque;
+    if (watch_update_mask2(watch, event_mask) != 0) {
+        free(watch);
+        return NULL;
+    }
+
+    return watch;
+}
+
+static void watch_update_mask(SpiceWatch *watch, int event_mask)
+{
+    DPRINTF(0, "fd %d to %d", watch->fd, event_mask);
+    watch_update_mask2(watch, event_mask);
+}
+
+static void watch_remove(SpiceWatch *watch)
+{
+    DPRINTF(0, "remove %p (fd %d)", watch, watch->fd);
+    RemoveNotifyFd(watch->fd);
+    free(watch);
+}
+#endif
+
+static void channel_event(int event, SpiceChannelEventInfo *info)
+{
+    NOT_IMPLEMENTED
+}
+
+
 SpiceCoreInterface *basic_event_loop_init(void)
 {
+#if GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) < 23
     ring_init(&watches);
+#endif
     bzero(&core, sizeof(core));
     core.base.major_version = SPICE_INTERFACE_CORE_MAJOR;
     core.base.minor_version = SPICE_INTERFACE_CORE_MINOR; // anything less then 3 and channel_event isn't called
@@ -355,7 +430,10 @@ SpiceCoreInterface *basic_event_loop_init(void)
     return &core;
 }
 
+
 void xspice_register_handlers(void)
 {
+#if GET_ABI_MAJOR(ABI_VIDEODRV_VERSION) < 23
     RegisterBlockAndWakeupHandlers(xspice_block_handler, xspice_wakeup_handler, 0);
+#endif
 }
-- 
2.9.3