compositor: add plugin-registry

Implement a simple register and lookup for function tables. This is
intended for plugins to expose APIs to other plugins.

It has been very hard to arrange a plugin to be able to call into
another plugin without modifying Weston core to explicitly support each
case. This patch fixes that.

The tests all pass.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Giulio Camuffo <giuliocamuffo@gmail.com>
dev
Pekka Paalanen 8 years ago
parent 24f917e723
commit 827b5d225d
  1. 8
      Makefile.am
  2. 6
      libweston/compositor.c
  3. 2
      libweston/compositor.h
  4. 156
      libweston/plugin-registry.c
  5. 55
      libweston/plugin-registry.h
  6. 101
      tests/plugin-registry-test.c

@ -90,6 +90,8 @@ libweston_la_SOURCES = \
libweston/noop-renderer.c \
libweston/pixman-renderer.c \
libweston/pixman-renderer.h \
libweston/plugin-registry.c \
libweston/plugin-registry.h \
libweston/timeline.c \
libweston/timeline.h \
libweston/timeline-object.h \
@ -235,6 +237,7 @@ libwestoninclude_HEADERS = \
libweston/compositor-rdp.h \
libweston/compositor-wayland.h \
libweston/compositor-x11.h \
libweston/plugin-registry.h \
libweston/timeline-object.h \
shared/matrix.h \
shared/config-parser.h \
@ -1092,6 +1095,7 @@ shared_tests = \
zuctest
module_tests = \
plugin-registry-test.la \
surface-test.la \
surface-global-test.la
@ -1143,6 +1147,10 @@ noinst_PROGRAMS += \
test_module_ldflags = \
-module -avoid-version -rpath $(libdir) $(COMPOSITOR_LIBS)
plugin_registry_test_la_SOURCES = tests/plugin-registry-test.c
plugin_registry_test_la_LDFLAGS = $(test_module_ldflags)
plugin_registry_test_la_CFLAGS = $(AM_CFLAGS) $(COMPOSITOR_CFLAGS)
surface_global_test_la_SOURCES = tests/surface-global-test.c
surface_global_test_la_LDFLAGS = $(test_module_ldflags)
surface_global_test_la_CFLAGS = $(AM_CFLAGS) $(COMPOSITOR_CFLAGS)

@ -61,6 +61,7 @@
#include "shared/timespec-util.h"
#include "git-version.h"
#include "version.h"
#include "plugin-registry.h"
#define DEFAULT_REPAINT_WINDOW 7 /* milliseconds */
@ -4702,6 +4703,8 @@ weston_compositor_create(struct wl_display *display, void *user_data)
wl_list_init(&ec->axis_binding_list);
wl_list_init(&ec->debug_binding_list);
wl_list_init(&ec->plugin_api_list);
weston_plane_init(&ec->primary_plane, ec, 0, 0);
weston_compositor_stack_plane(ec, &ec->primary_plane, NULL);
@ -4947,6 +4950,9 @@ weston_compositor_destroy(struct weston_compositor *compositor)
if (compositor->backend)
compositor->backend->destroy(compositor);
weston_plugin_api_destroy_list(compositor);
free(compositor);
}

@ -783,6 +783,8 @@ struct weston_compositor {
struct weston_launcher *launcher;
struct wl_list plugin_api_list; /* struct weston_plugin_api::link */
uint32_t output_id_pool;
struct xkb_rule_names xkb_names;

@ -0,0 +1,156 @@
/*
* Copyright (C) 2016 DENSO CORPORATION
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include "compositor.h"
#include "plugin-registry.h"
struct weston_plugin_api {
struct wl_list link; /**< in weston_compositor::plugin_api_list */
char *api_name; /**< The search key */
const void *vtable; /**< The function table */
size_t vtable_size; /**< Size of the function table in bytes */
};
/** Register an implementation of an API
*
* \param compositor The compositor instance.
* \param api_name The API name which other plugins use to find the
* implementation.
* \param vtable Pointer to the function table of the API.
* \param vtable_size Size of the function table in bytes.
* \return 0 on success, -1 on error, -2 if api_name already registered
*
* This call makes the given vtable to be reachable via
* weston_plugin_api_get(). Calls through the vtable may start happening
* as soon as the caller returns after success. Argument vtable must not be
* NULL. Argument api_name must be non-NULL and non-zero length.
*
* You can increase the function table size without breaking the ABI.
* To cater for ABI breaks, it is recommended to have api_name include a
* version number.
*
* A registered API cannot be unregistered. However, calls through a
* registered API must not be made from the compositor destroy signal handlers.
*/
WL_EXPORT int
weston_plugin_api_register(struct weston_compositor *compositor,
const char *api_name,
const void *vtable,
size_t vtable_size)
{
struct weston_plugin_api *wpa;
assert(api_name);
assert(strlen(api_name) > 0);
assert(vtable);
if (!api_name || !vtable || strlen(api_name) == 0)
return -1;
wl_list_for_each(wpa, &compositor->plugin_api_list, link)
if (strcmp(wpa->api_name, api_name) == 0)
return -2;
wpa = zalloc(sizeof(*wpa));
if (!wpa)
return -1;
wpa->api_name = strdup(api_name);
wpa->vtable = vtable;
wpa->vtable_size = vtable_size;
if (!wpa->api_name) {
free(wpa);
return -1;
}
wl_list_insert(&compositor->plugin_api_list, &wpa->link);
weston_log("Registered plugin API '%s' of size %zd\n",
wpa->api_name, wpa->vtable_size);
return 0;
}
/** Internal function to free registered APIs
*
* \param compositor The compositor instance.
*/
void
weston_plugin_api_destroy_list(struct weston_compositor *compositor)
{
struct weston_plugin_api *wpa, *tmp;
wl_list_for_each_safe(wpa, tmp, &compositor->plugin_api_list, link) {
free(wpa->api_name);
wl_list_remove(&wpa->link);
free(wpa);
}
}
/** Fetch the implementation of an API
*
* \param compositor The compositor instance.
* \param api_name The name of the API to search for.
* \param vtable_size The expected function table size in bytes.
* \return Pointer to the function table, or NULL on error.
*
* Find the function table corresponding to api_name. The vtable_size here
* must be less or equal to the vtable_size given in the corresponding
* weston_plugin_api_register() call made by the implementing plugin.
*
* Calls can be made through the function table immediately. However, calls
* must not be made from or after the compositor destroy signal handler.
*/
WL_EXPORT const void *
weston_plugin_api_get(struct weston_compositor *compositor,
const char *api_name,
size_t vtable_size)
{
struct weston_plugin_api *wpa;
assert(api_name);
if (!api_name)
return NULL;
wl_list_for_each(wpa, &compositor->plugin_api_list, link) {
if (strcmp(wpa->api_name, api_name) != 0)
continue;
if (vtable_size <= wpa->vtable_size)
return wpa->vtable;
return NULL;
}
return NULL;
}

@ -0,0 +1,55 @@
/*
* Copyright (C) 2016 DENSO CORPORATION
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef WESTON_PLUGIN_REGISTRY_H
#define WESTON_PLUGIN_REGISTRY_H
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
struct weston_compositor;
int
weston_plugin_api_register(struct weston_compositor *compositor,
const char *api_name,
const void *vtable,
size_t vtable_size);
const void *
weston_plugin_api_get(struct weston_compositor *compositor,
const char *api_name,
size_t vtable_size);
void
weston_plugin_api_destroy_list(struct weston_compositor *compositor);
#ifdef __cplusplus
}
#endif
#endif /* WESTON_PLUGIN_REGISTRY_H */

@ -0,0 +1,101 @@
/*
* Copyright (C) 2016 DENSO CORPORATION
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <assert.h>
#include "compositor.h"
#include "plugin-registry.h"
static void
dummy_func(void)
{
}
static const struct my_api {
void (*func1)(void);
void (*func2)(void);
void (*func3)(void);
} my_test_api = {
dummy_func,
dummy_func,
dummy_func,
};
#define MY_API_NAME "test_my_api_v1"
static void
init_tests(struct weston_compositor *compositor)
{
assert(weston_plugin_api_get(compositor, MY_API_NAME,
sizeof(my_test_api)) == NULL);
assert(weston_plugin_api_register(compositor, MY_API_NAME, &my_test_api,
sizeof(my_test_api)) == 0);
assert(weston_plugin_api_register(compositor, MY_API_NAME, &my_test_api,
sizeof(my_test_api)) == -2);
assert(weston_plugin_api_get(compositor, MY_API_NAME,
sizeof(my_test_api)) == &my_test_api);
assert(weston_plugin_api_register(compositor, "another", &my_test_api,
sizeof(my_test_api)) == 0);
}
static void
runtime_tests(void *data)
{
struct weston_compositor *compositor = data;
const struct my_api *api;
size_t sz = sizeof(struct my_api);
assert(weston_plugin_api_get(compositor, MY_API_NAME, sz) ==
&my_test_api);
assert(weston_plugin_api_get(compositor, MY_API_NAME, sz - 4) ==
&my_test_api);
assert(weston_plugin_api_get(compositor, MY_API_NAME, sz + 4) == NULL);
api = weston_plugin_api_get(compositor, MY_API_NAME, sz);
assert(api && api->func2 == dummy_func);
wl_display_terminate(compositor->wl_display);
}
WL_EXPORT int
module_init(struct weston_compositor *compositor, int *argc, char *argv[])
{
struct wl_event_loop *loop;
init_tests(compositor);
loop = wl_display_get_event_loop(compositor->wl_display);
wl_event_loop_add_idle(loop, runtime_tests, compositor);
return 0;
}
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