wlroots/backend/backend.c

478 lines
12 KiB
C

#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <wayland-server-core.h>
#include <wlr/backend/headless.h>
#include <wlr/backend/interface.h>
#include <wlr/backend/multi.h>
#include <wlr/backend/noop.h>
#include <wlr/backend/session.h>
#include <wlr/backend/wayland.h>
#include <wlr/config.h>
#include <wlr/render/wlr_renderer.h>
#include <wlr/util/log.h>
#include "backend/backend.h"
#include "backend/multi.h"
#include "render/allocator/allocator.h"
#include "util/signal.h"
#if WLR_HAS_DRM_BACKEND
#include <wlr/backend/drm.h>
#endif
#if WLR_HAS_LIBINPUT_BACKEND
#include <wlr/backend/libinput.h>
#endif
#if WLR_HAS_X11_BACKEND
#include <wlr/backend/x11.h>
#endif
#define WAIT_SESSION_TIMEOUT 10000 // ms
void wlr_backend_init(struct wlr_backend *backend,
const struct wlr_backend_impl *impl) {
assert(backend);
backend->impl = impl;
wl_signal_init(&backend->events.destroy);
wl_signal_init(&backend->events.new_input);
wl_signal_init(&backend->events.new_output);
}
void wlr_backend_finish(struct wlr_backend *backend) {
wlr_signal_emit_safe(&backend->events.destroy, backend);
wlr_allocator_destroy(backend->allocator);
if (backend->has_own_renderer) {
wlr_renderer_destroy(backend->renderer);
}
}
bool wlr_backend_start(struct wlr_backend *backend) {
if (backend->impl->start) {
return backend->impl->start(backend);
}
return true;
}
void wlr_backend_destroy(struct wlr_backend *backend) {
if (!backend) {
return;
}
if (backend->impl && backend->impl->destroy) {
backend->impl->destroy(backend);
} else {
free(backend);
}
}
static bool backend_create_renderer(struct wlr_backend *backend) {
if (backend->renderer != NULL) {
return true;
}
backend->renderer = wlr_renderer_autocreate(backend);
if (backend->renderer == NULL) {
return false;
}
backend->has_own_renderer = true;
return true;
}
struct wlr_renderer *wlr_backend_get_renderer(struct wlr_backend *backend) {
if (backend->impl->get_renderer) {
return backend->impl->get_renderer(backend);
}
if (backend_get_buffer_caps(backend) != 0) {
// If the backend is capable of presenting buffers, automatically create
// the renderer if necessary.
if (!backend_create_renderer(backend)) {
wlr_log(WLR_ERROR, "Failed to create backend renderer");
return NULL;
}
return backend->renderer;
}
return NULL;
}
struct wlr_session *wlr_backend_get_session(struct wlr_backend *backend) {
if (backend->impl->get_session) {
return backend->impl->get_session(backend);
}
return NULL;
}
static uint64_t get_current_time_ms(void) {
struct timespec ts = {0};
clock_gettime(CLOCK_MONOTONIC, &ts);
return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}
static struct wlr_session *session_create_and_wait(struct wl_display *disp) {
struct wlr_session *session = wlr_session_create(disp);
if (!session) {
wlr_log(WLR_ERROR, "Failed to start a session");
return NULL;
}
if (!session->active) {
wlr_log(WLR_INFO, "Waiting for a session to become active");
uint64_t started_at = get_current_time_ms();
uint64_t timeout = WAIT_SESSION_TIMEOUT;
struct wl_event_loop *event_loop =
wl_display_get_event_loop(session->display);
while (!session->active) {
int ret = wl_event_loop_dispatch(event_loop, (int)timeout);
if (ret < 0) {
wlr_log_errno(WLR_ERROR, "Failed to wait for session active: "
"wl_event_loop_dispatch failed");
return NULL;
}
uint64_t now = get_current_time_ms();
if (now >= started_at + WAIT_SESSION_TIMEOUT) {
break;
}
timeout = started_at + WAIT_SESSION_TIMEOUT - now;
}
if (!session->active) {
wlr_log(WLR_ERROR, "Timeout waiting session to become active");
return NULL;
}
}
return session;
}
clockid_t wlr_backend_get_presentation_clock(struct wlr_backend *backend) {
if (backend->impl->get_presentation_clock) {
return backend->impl->get_presentation_clock(backend);
}
return CLOCK_MONOTONIC;
}
int wlr_backend_get_drm_fd(struct wlr_backend *backend) {
if (!backend->impl->get_drm_fd) {
return -1;
}
return backend->impl->get_drm_fd(backend);
}
uint32_t backend_get_buffer_caps(struct wlr_backend *backend) {
if (!backend->impl->get_buffer_caps) {
return 0;
}
return backend->impl->get_buffer_caps(backend);
}
struct wlr_allocator *backend_get_allocator(struct wlr_backend *backend) {
if (backend->allocator != NULL) {
return backend->allocator;
}
struct wlr_renderer *renderer = wlr_backend_get_renderer(backend);
if (renderer == NULL) {
return NULL;
}
backend->allocator = wlr_allocator_autocreate(backend, renderer);
if (backend->allocator == NULL) {
wlr_log(WLR_ERROR, "Failed to create backend allocator");
}
return backend->allocator;
}
static size_t parse_outputs_env(const char *name) {
const char *outputs_str = getenv(name);
if (outputs_str == NULL) {
return 1;
}
char *end;
int outputs = (int)strtol(outputs_str, &end, 10);
if (*end || outputs < 0) {
wlr_log(WLR_ERROR, "%s specified with invalid integer, ignoring", name);
return 1;
}
return outputs;
}
static struct wlr_backend *ensure_backend_renderer_and_allocator(
struct wlr_backend *backend) {
struct wlr_renderer *renderer = wlr_backend_get_renderer(backend);
if (renderer == NULL) {
wlr_backend_destroy(backend);
return NULL;
}
struct wlr_allocator *allocator = backend_get_allocator(backend);
if (allocator == NULL) {
wlr_backend_destroy(backend);
return NULL;
}
return backend;
}
static struct wlr_backend *attempt_wl_backend(struct wl_display *display) {
struct wlr_backend *backend = wlr_wl_backend_create(display, NULL);
if (backend == NULL) {
return NULL;
}
size_t outputs = parse_outputs_env("WLR_WL_OUTPUTS");
for (size_t i = 0; i < outputs; ++i) {
wlr_wl_output_create(backend);
}
return ensure_backend_renderer_and_allocator(backend);
}
#if WLR_HAS_X11_BACKEND
static struct wlr_backend *attempt_x11_backend(struct wl_display *display,
const char *x11_display) {
struct wlr_backend *backend = wlr_x11_backend_create(display, x11_display);
if (backend == NULL) {
return NULL;
}
size_t outputs = parse_outputs_env("WLR_X11_OUTPUTS");
for (size_t i = 0; i < outputs; ++i) {
wlr_x11_output_create(backend);
}
return ensure_backend_renderer_and_allocator(backend);
}
#endif
static struct wlr_backend *attempt_headless_backend(
struct wl_display *display) {
struct wlr_backend *backend = wlr_headless_backend_create(display);
if (backend == NULL) {
return NULL;
}
size_t outputs = parse_outputs_env("WLR_HEADLESS_OUTPUTS");
for (size_t i = 0; i < outputs; ++i) {
wlr_headless_add_output(backend, 1280, 720);
}
return ensure_backend_renderer_and_allocator(backend);
}
static struct wlr_backend *attempt_noop_backend(struct wl_display *display) {
struct wlr_backend *backend = wlr_noop_backend_create(display);
if (backend == NULL) {
return NULL;
}
size_t outputs = parse_outputs_env("WLR_NOOP_OUTPUTS");
for (size_t i = 0; i < outputs; ++i) {
wlr_noop_add_output(backend);
}
return backend;
}
#if WLR_HAS_DRM_BACKEND
static struct wlr_backend *attempt_drm_backend(struct wl_display *display,
struct wlr_backend *backend, struct wlr_session *session) {
struct wlr_device *gpus[8];
ssize_t num_gpus = wlr_session_find_gpus(session, 8, gpus);
if (num_gpus < 0) {
wlr_log(WLR_ERROR, "Failed to find GPUs");
return NULL;
}
if (num_gpus == 0) {
wlr_log(WLR_ERROR, "Found 0 GPUs, cannot create backend");
return NULL;
} else {
wlr_log(WLR_INFO, "Found %zu GPUs", num_gpus);
}
struct wlr_backend *primary_drm = NULL;
for (size_t i = 0; i < (size_t)num_gpus; ++i) {
struct wlr_backend *drm = wlr_drm_backend_create(display, session,
gpus[i], primary_drm);
if (!drm) {
wlr_log(WLR_ERROR, "Failed to create DRM backend");
continue;
}
if (!primary_drm) {
primary_drm = drm;
}
wlr_multi_backend_add(backend, drm);
}
if (!primary_drm) {
wlr_log(WLR_ERROR, "Could not successfully create backend on any GPU");
return NULL;
}
return ensure_backend_renderer_and_allocator(primary_drm);
}
#endif
static struct wlr_backend *attempt_backend_by_name(struct wl_display *display,
struct wlr_backend *backend, struct wlr_session **session,
const char *name) {
if (strcmp(name, "wayland") == 0) {
return attempt_wl_backend(display);
#if WLR_HAS_X11_BACKEND
} else if (strcmp(name, "x11") == 0) {
return attempt_x11_backend(display, NULL);
#endif
} else if (strcmp(name, "headless") == 0) {
return attempt_headless_backend(display);
} else if (strcmp(name, "noop") == 0) {
return attempt_noop_backend(display);
} else if (strcmp(name, "drm") == 0 || strcmp(name, "libinput") == 0) {
// DRM and libinput need a session
if (!*session) {
*session = session_create_and_wait(display);
if (!*session) {
wlr_log(WLR_ERROR, "failed to start a session");
return NULL;
}
}
if (strcmp(name, "libinput") == 0) {
#if WLR_HAS_LIBINPUT_BACKEND
return wlr_libinput_backend_create(display, *session);
#else
return NULL;
#endif
} else {
#if WLR_HAS_DRM_BACKEND
return attempt_drm_backend(display, backend, *session);
#else
return NULL;
#endif
}
}
wlr_log(WLR_ERROR, "unrecognized backend '%s'", name);
return NULL;
}
struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
struct wlr_backend *backend = wlr_multi_backend_create(display);
struct wlr_multi_backend *multi = (struct wlr_multi_backend *)backend;
if (!backend) {
wlr_log(WLR_ERROR, "could not allocate multibackend");
return NULL;
}
char *names = getenv("WLR_BACKENDS");
if (names) {
wlr_log(WLR_INFO, "Loading user-specified backends due to WLR_BACKENDS: %s",
names);
names = strdup(names);
if (names == NULL) {
wlr_log(WLR_ERROR, "allocation failed");
wlr_backend_destroy(backend);
return NULL;
}
char *saveptr;
char *name = strtok_r(names, ",", &saveptr);
while (name != NULL) {
struct wlr_backend *subbackend = attempt_backend_by_name(display,
backend, &multi->session, name);
if (subbackend == NULL) {
wlr_log(WLR_ERROR, "failed to start backend '%s'", name);
wlr_session_destroy(multi->session);
wlr_backend_destroy(backend);
free(names);
return NULL;
}
if (!wlr_multi_backend_add(backend, subbackend)) {
wlr_log(WLR_ERROR, "failed to add backend '%s'", name);
wlr_session_destroy(multi->session);
wlr_backend_destroy(backend);
free(names);
return NULL;
}
name = strtok_r(NULL, ",", &saveptr);
}
free(names);
return backend;
}
if (getenv("WAYLAND_DISPLAY") || getenv("WAYLAND_SOCKET")) {
struct wlr_backend *wl_backend = attempt_wl_backend(display);
if (!wl_backend) {
goto error;
}
wlr_multi_backend_add(backend, wl_backend);
return backend;
}
#if WLR_HAS_X11_BACKEND
const char *x11_display = getenv("DISPLAY");
if (x11_display) {
struct wlr_backend *x11_backend =
attempt_x11_backend(display, x11_display);
if (!x11_backend) {
goto error;
}
wlr_multi_backend_add(backend, x11_backend);
return backend;
}
#endif
// Attempt DRM+libinput
multi->session = session_create_and_wait(display);
if (!multi->session) {
wlr_log(WLR_ERROR, "Failed to start a DRM session");
wlr_backend_destroy(backend);
return NULL;
}
#if WLR_HAS_LIBINPUT_BACKEND
struct wlr_backend *libinput = wlr_libinput_backend_create(display,
multi->session);
if (!libinput) {
wlr_log(WLR_ERROR, "Failed to start libinput backend");
wlr_session_destroy(multi->session);
wlr_backend_destroy(backend);
return NULL;
}
wlr_multi_backend_add(backend, libinput);
#endif
#if WLR_HAS_DRM_BACKEND
struct wlr_backend *primary_drm =
attempt_drm_backend(display, backend, multi->session);
if (!primary_drm) {
wlr_log(WLR_ERROR, "Failed to open any DRM device");
wlr_session_destroy(multi->session);
wlr_backend_destroy(backend);
return NULL;
}
return backend;
#endif
error:
wlr_backend_destroy(backend);
return NULL;
}