loader/wayland: Add fallback wl_display_dispatch_queue_timeout

This is almost a 1:1 copy of the same function in libwayland. If the version
with the symbol propagates far enough the fallback can be removed again.

Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27511>

meson.build

@@ -2014,6 +2014,12 @@ if with_platform_wayland
     dep_wayland_egl_headers = dep_wayland_egl.partial_dependency(compile_args : true)
   endif
   pre_args += '-DWL_HIDE_DEPRECATED'
+  if cc.has_function(
+      'wl_display_dispatch_queue_timeout',
+      prefix : '#include <wayland-client.h>',
+      dependencies: dep_wayland_client)
+    pre_args += ['-DHAVE_WL_DISPATCH_QUEUE_TIMEOUT']
+  endif
 endif
 
 dep_x11 = null_dep

src/loader/loader_wayland_helper.c

@@ -0,0 +1,129 @@
+/*
+ * Copyright © 2022 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <poll.h>
+#include <errno.h>
+
+#include "loader_wayland_helper.h"
+
+#ifndef HAVE_WL_DISPATCH_QUEUE_TIMEOUT
+static int
+wl_display_poll(struct wl_display *display,
+                short int events,
+                const struct timespec *timeout)
+{
+   int ret;
+   struct pollfd pfd[1];
+   struct timespec now;
+   struct timespec deadline = {0};
+   struct timespec result;
+   struct timespec *remaining_timeout = NULL;
+
+   if (timeout) {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      timespec_add(&deadline, &now, timeout);
+   }
+
+   pfd[0].fd = wl_display_get_fd(display);
+   pfd[0].events = events;
+   do {
+      if (timeout) {
+         clock_gettime(CLOCK_MONOTONIC, &now);
+         timespec_sub_saturate(&result, &deadline, &now);
+         remaining_timeout = &result;
+      }
+      ret = ppoll(pfd, 1, remaining_timeout, NULL);
+   } while (ret == -1 && errno == EINTR);
+
+   return ret;
+}
+
+int
+wl_display_dispatch_queue_timeout(struct wl_display *display,
+                                  struct wl_event_queue *queue,
+                                  const struct timespec *timeout)
+{
+   int ret;
+   struct timespec now;
+   struct timespec deadline = {0};
+   struct timespec result;
+   struct timespec *remaining_timeout = NULL;
+
+   if (timeout) {
+      clock_gettime(CLOCK_MONOTONIC, &now);
+      timespec_add(&deadline, &now, timeout);
+   }
+
+   if (wl_display_prepare_read_queue(display, queue) == -1)
+      return wl_display_dispatch_queue_pending(display, queue);
+
+   while (true) {
+      ret = wl_display_flush(display);
+
+      if (ret != -1 || errno != EAGAIN)
+         break;
+
+      if (timeout) {
+         clock_gettime(CLOCK_MONOTONIC, &now);
+         timespec_sub_saturate(&result, &deadline, &now);
+         remaining_timeout = &result;
+      }
+      ret = wl_display_poll(display, POLLOUT, remaining_timeout);
+
+      if (ret <= 0) {
+         wl_display_cancel_read(display);
+         return ret;
+      }
+   }
+
+   /* Don't stop if flushing hits an EPIPE; continue so we can read any
+    * protocol error that may have triggered it. */
+   if (ret < 0 && errno != EPIPE) {
+      wl_display_cancel_read(display);
+      return -1;
+   }
+
+   while (true) {
+      if (timeout) {
+         clock_gettime(CLOCK_MONOTONIC, &now);
+         timespec_sub_saturate(&result, &deadline, &now);
+         remaining_timeout = &result;
+      }
+
+      ret = wl_display_poll(display, POLLIN, remaining_timeout);
+      if (ret <= 0) {
+         wl_display_cancel_read(display);
+         break;
+      }
+
+      ret = wl_display_read_events(display);
+      if (ret == -1)
+         break;
+
+      ret = wl_display_dispatch_queue_pending(display, queue);
+      if (ret != 0)
+         break;
+   }
+
+   return ret;
+}
+#endif

src/loader/loader_wayland_helper.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright © 2022 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef LOADER_WAYLAND_HELPER_HEADER_H
+#define LOADER_WAYLAND_HELPER_HEADER_H
+
+#ifndef HAVE_WL_DISPATCH_QUEUE_TIMEOUT
+
+#include <wayland-client.h>
+#include <util/timespec.h>
+int
+wl_display_dispatch_queue_timeout(struct wl_display *display,
+                                  struct wl_event_queue *queue,
+                                  const struct timespec *deadline);
+#endif
+
+#endif

src/loader/meson.build

@@ -37,6 +37,21 @@ else
   libloader_dri3_helper = []
 endif
 
+if with_platform_wayland
+  libloader_wayland_helper = static_library(
+    'loader_wayland_helper',
+    'loader_wayland_helper.c',
+    gnu_symbol_visibility : 'hidden',
+    include_directories : [inc_include, inc_src],
+    dependencies : [
+      dep_wayland_client,
+    ],
+    build_by_default : false,
+  )
+else
+  libloader_wayland_helper = []
+endif
+
 loader_c_args = [
   '-DUSE_DRICONF',
   '-DDEFAULT_DRIVER_DIR="@0@"'.format(dri_search_path),

src/meson.build

@@ -63,6 +63,9 @@ if cc.get_argument_syntax() == 'msvc'
 else
   idep_getopt = null_dep
 endif
+if with_gallium or with_gbm or with_platform_wayland
+  subdir('loader')
+endif
 if with_gallium
   subdir('mapi')
 endif
@@ -115,9 +118,6 @@ endif
 if with_gallium_asahi or with_tools.contains('asahi')
   subdir('asahi')
 endif
-if with_gallium or with_gbm
-  subdir('loader')
-endif
 if with_gbm
   subdir('gbm')
 else

src/vulkan/wsi/meson.build

@@ -68,6 +68,7 @@ libvulkan_wsi = static_library(
     idep_vulkan_runtime_headers, idep_xmlconfig, idep_mesautil, platform_deps,
     idep_blake3
   ],
+  link_with: libloader_wayland_helper,
   gnu_symbol_visibility : 'hidden',
   build_by_default : false,
 )

src/vulkan/wsi/wsi_common_wayland.c

@@ -54,6 +54,8 @@
 #include <util/anon_file.h>
 #include <util/os_time.h>
 
+#include <loader/loader_wayland_helper.h>
+
 #ifdef MAJOR_IN_MKDEV
 #include <sys/mkdev.h>
 #endif