[PATCH weston v2 1/2] compositor: add plugin-registry
Giulio Camuffo
giuliocamuffo at gmail.com
Wed Jun 29 09:54:26 UTC 2016
From: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
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 at collabora.co.uk>
Signed-off-by: Giulio Camuffo <giuliocamuffo at gmail.com>
---
Makefile.am | 8 +++
libweston/compositor.c | 6 ++
libweston/compositor.h | 2 +
libweston/plugin-registry.c | 156 +++++++++++++++++++++++++++++++++++++++++++
libweston/plugin-registry.h | 55 +++++++++++++++
tests/plugin-registry-test.c | 101 ++++++++++++++++++++++++++++
6 files changed, 328 insertions(+)
create mode 100644 libweston/plugin-registry.c
create mode 100644 libweston/plugin-registry.h
create mode 100644 tests/plugin-registry-test.c
diff --git a/Makefile.am b/Makefile.am
index 67ac351..1d297cc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -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)
diff --git a/libweston/compositor.c b/libweston/compositor.c
index 37d94ec..113f5fc 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -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);
}
diff --git a/libweston/compositor.h b/libweston/compositor.h
index 9e5155c..8014a42 100644
--- a/libweston/compositor.h
+++ b/libweston/compositor.h
@@ -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;
diff --git a/libweston/plugin-registry.c b/libweston/plugin-registry.c
new file mode 100644
index 0000000..48c4220
--- /dev/null
+++ b/libweston/plugin-registry.c
@@ -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;
+}
diff --git a/libweston/plugin-registry.h b/libweston/plugin-registry.h
new file mode 100644
index 0000000..3f5618d
--- /dev/null
+++ b/libweston/plugin-registry.h
@@ -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 */
diff --git a/tests/plugin-registry-test.c b/tests/plugin-registry-test.c
new file mode 100644
index 0000000..7fc88f3
--- /dev/null
+++ b/tests/plugin-registry-test.c
@@ -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;
+}
--
2.9.0
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