From 827b5d225de14f0c54b77040671370bb09d0fa0a Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Wed, 29 Jun 2016 11:54:26 +0200 Subject: [PATCH] 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 Signed-off-by: Giulio Camuffo --- 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 9a1c4239..f45a87fb 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 37d94ec9..113f5fcd 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 49ef0631..33b86c10 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 00000000..48c42200 --- /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 +#include +#include + +#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 00000000..3f5618d7 --- /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 + +#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 00000000..7fc88f39 --- /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 + +#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; +}