Move swaybar's event loop to common directory and refactor

* The loop functions are now prefixed with `loop_`.
* It is now easy to add timers to the loop.
* Timers are implemented using pollfd and timerfd, rather than manually
checking them when any other event happens to arrive.
This commit is contained in:
Ryan Dwyer 2018-10-13 16:04:37 +10:00
parent 7f2e6d812a
commit 4056c09e13
10 changed files with 172 additions and 192 deletions

105
common/loop.c Normal file
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@ -0,0 +1,105 @@
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <poll.h>
#include <sys/timerfd.h>
#include <unistd.h>
#include "list.h"
#include "log.h"
#include "loop.h"
struct loop_event {
void (*callback)(int fd, short mask, void *data);
void *data;
};
struct loop {
struct pollfd *fds;
int fd_length;
int fd_capacity;
list_t *events; // struct loop_event
};
struct loop *loop_create(void) {
struct loop *loop = calloc(1, sizeof(struct loop));
if (!loop) {
wlr_log(WLR_ERROR, "Unable to allocate memory for loop");
return NULL;
}
loop->fd_capacity = 10;
loop->fds = malloc(sizeof(struct pollfd) * loop->fd_capacity);
loop->events = create_list();
return loop;
}
void loop_destroy(struct loop *loop) {
list_foreach(loop->events, free);
list_free(loop->events);
free(loop);
}
void loop_poll(struct loop *loop) {
poll(loop->fds, loop->fd_length, -1);
for (int i = 0; i < loop->fd_length; ++i) {
struct pollfd pfd = loop->fds[i];
struct loop_event *event = loop->events->items[i];
// Always send these events
unsigned events = pfd.events | POLLHUP | POLLERR;
if (pfd.revents & events) {
event->callback(pfd.fd, pfd.revents, event->data);
}
}
}
struct loop_event *loop_add_fd(struct loop *loop, int fd, short mask,
void (*callback)(int fd, short mask, void *data), void *data) {
struct pollfd pfd = {fd, mask, 0};
if (loop->fd_length == loop->fd_capacity) {
loop->fd_capacity += 10;
loop->fds = realloc(loop->fds, sizeof(struct pollfd) * loop->fd_capacity);
}
loop->fds[loop->fd_length++] = pfd;
struct loop_event *event = calloc(1, sizeof(struct loop_event));
event->callback = callback;
event->data = data;
list_add(loop->events, event);
return event;
}
struct loop_event *loop_add_timer(struct loop *loop, int ms,
void (*callback)(int fd, short mask, void *data), void *data) {
int fd = timerfd_create(CLOCK_MONOTONIC, 0);
struct itimerspec its;
its.it_interval.tv_sec = 0;
its.it_interval.tv_nsec = 0;
its.it_value.tv_sec = ms / 1000000000;
its.it_value.tv_nsec = (ms * 1000000) % 1000000000;
timerfd_settime(fd, 0, &its, NULL);
return loop_add_fd(loop, fd, POLLIN, callback, data);
}
bool loop_remove_event(struct loop *loop, struct loop_event *event) {
for (int i = 0; i < loop->events->length; ++i) {
if (loop->events->items[i] == event) {
list_del(loop->events, i);
loop->fd_length--;
memmove(&loop->fds[i], &loop->fds[i + 1], sizeof(void*) * (loop->fd_length - i));
free(event);
return true;
}
}
return false;
}

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@ -5,6 +5,7 @@ lib_sway_common = static_library(
'cairo.c', 'cairo.c',
'ipc-client.c', 'ipc-client.c',
'log.c', 'log.c',
'loop.c',
'list.c', 'list.c',
'pango.c', 'pango.c',
'readline.c', 'readline.c',

47
include/loop.h Normal file
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@ -0,0 +1,47 @@
#ifndef _SWAY_LOOP_H
#define _SWAY_LOOP_H
#include <stdbool.h>
/**
* This is an event loop system designed for sway clients, not sway itself.
*
* It uses pollfds to block on multiple file descriptors at once, and provides
* an easy way to set timers. Typically the Wayland display's fd will be one of
* the fds in the loop.
*/
struct loop;
/**
* Create an event loop.
*/
struct loop *loop_create(void);
/**
* Destroy the event loop (eg. on program termination).
*/
void loop_destroy(struct loop *loop);
/**
* Poll the event loop. This will block until one of the fds has data.
*/
void loop_poll(struct loop *loop);
/**
* Add an fd to the loop.
*/
struct loop_event *loop_add_fd(struct loop *loop, int fd, short mask,
void (*func)(int fd, short mask, void *data), void *data);
/**
* Add a timer to the loop.
*/
struct loop_event *loop_add_timer(struct loop *loop, int ms,
void (*callback)(int fd, short mask, void *data), void *data);
/**
* Remove an event from the loop.
*/
bool loop_remove_event(struct loop *loop, struct loop_event *event);
#endif

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@ -8,6 +8,8 @@
struct swaybar_config; struct swaybar_config;
struct swaybar_output; struct swaybar_output;
struct swaybar_workspace; struct swaybar_workspace;
struct loop;
struct loop_event;
struct swaybar_pointer { struct swaybar_pointer {
struct wl_pointer *pointer; struct wl_pointer *pointer;
@ -66,6 +68,9 @@ struct swaybar {
struct swaybar_pointer pointer; struct swaybar_pointer pointer;
struct status_line *status; struct status_line *status;
struct loop *eventloop;
struct loop_event *status_event;
int ipc_event_socketfd; int ipc_event_socketfd;
int ipc_socketfd; int ipc_socketfd;

View file

@ -1,26 +0,0 @@
#ifndef _SWAYBAR_EVENT_LOOP_H
#define _SWAYBAR_EVENT_LOOP_H
#include <stdbool.h>
#include <time.h>
void add_event(int fd, short mask,
void(*cb)(int fd, short mask, void *data),
void *data);
// Not guaranteed to notify cb immediately
void add_timer(timer_t timer,
void(*cb)(timer_t timer, void *data),
void *data);
// Returns false if nothing exists, true otherwise
bool remove_event(int fd);
// Returns false if nothing exists, true otherwise
bool remove_timer(timer_t timer);
// Blocks and returns after sending callbacks
void event_loop_poll(void);
void init_event_loop(void);
#endif

View file

@ -14,6 +14,8 @@ enum status_protocol {
}; };
struct status_line { struct status_line {
struct swaybar *bar;
pid_t pid; pid_t pid;
int read_fd, write_fd; int read_fd, write_fd;
FILE *read, *write; FILE *read, *write;

View file

@ -18,7 +18,6 @@
#endif #endif
#include "swaybar/bar.h" #include "swaybar/bar.h"
#include "swaybar/config.h" #include "swaybar/config.h"
#include "swaybar/event_loop.h"
#include "swaybar/i3bar.h" #include "swaybar/i3bar.h"
#include "swaybar/ipc.h" #include "swaybar/ipc.h"
#include "swaybar/status_line.h" #include "swaybar/status_line.h"
@ -26,6 +25,7 @@
#include "ipc-client.h" #include "ipc-client.h"
#include "list.h" #include "list.h"
#include "log.h" #include "log.h"
#include "loop.h"
#include "pool-buffer.h" #include "pool-buffer.h"
#include "wlr-layer-shell-unstable-v1-client-protocol.h" #include "wlr-layer-shell-unstable-v1-client-protocol.h"
#include "xdg-output-unstable-v1-client-protocol.h" #include "xdg-output-unstable-v1-client-protocol.h"
@ -573,7 +573,7 @@ static void set_bar_dirty(struct swaybar *bar) {
bool bar_setup(struct swaybar *bar, const char *socket_path) { bool bar_setup(struct swaybar *bar, const char *socket_path) {
bar_init(bar); bar_init(bar);
init_event_loop(); bar->eventloop = loop_create();
bar->ipc_socketfd = ipc_open_socket(socket_path); bar->ipc_socketfd = ipc_open_socket(socket_path);
bar->ipc_event_socketfd = ipc_open_socket(socket_path); bar->ipc_event_socketfd = ipc_open_socket(socket_path);
@ -582,6 +582,7 @@ bool bar_setup(struct swaybar *bar, const char *socket_path) {
} }
if (bar->config->status_command) { if (bar->config->status_command) {
bar->status = status_line_init(bar->config->status_command); bar->status = status_line_init(bar->config->status_command);
bar->status->bar = bar;
} }
bar->display = wl_display_connect(NULL); bar->display = wl_display_connect(NULL);
@ -646,21 +647,23 @@ static void status_in(int fd, short mask, void *data) {
if (mask & (POLLHUP | POLLERR)) { if (mask & (POLLHUP | POLLERR)) {
status_error(bar->status, "[error reading from status command]"); status_error(bar->status, "[error reading from status command]");
set_bar_dirty(bar); set_bar_dirty(bar);
remove_event(fd); loop_remove_event(bar->eventloop, bar->status_event);
} else if (status_handle_readable(bar->status)) { } else if (status_handle_readable(bar->status)) {
set_bar_dirty(bar); set_bar_dirty(bar);
} }
} }
void bar_run(struct swaybar *bar) { void bar_run(struct swaybar *bar) {
add_event(wl_display_get_fd(bar->display), POLLIN, display_in, bar); loop_add_fd(bar->eventloop, wl_display_get_fd(bar->display), POLLIN,
add_event(bar->ipc_event_socketfd, POLLIN, ipc_in, bar); display_in, bar);
loop_add_fd(bar->eventloop, bar->ipc_event_socketfd, POLLIN, ipc_in, bar);
if (bar->status) { if (bar->status) {
add_event(bar->status->read_fd, POLLIN, status_in, bar); bar->status_event = loop_add_fd(
bar->eventloop, bar->status->read_fd, POLLIN, status_in, bar);
} }
while (1) { while (1) {
wl_display_flush(bar->display); wl_display_flush(bar->display);
event_loop_poll(); loop_poll(bar->eventloop);
} }
} }

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@ -1,156 +0,0 @@
#define _XOPEN_SOURCE 700
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <strings.h>
#include <poll.h>
#include <time.h>
#include "swaybar/event_loop.h"
#include "list.h"
struct event_item {
void (*cb)(int fd, short mask, void *data);
void *data;
};
struct timer_item {
timer_t timer;
void (*cb)(timer_t timer, void *data);
void *data;
};
static struct {
// The order of each must be kept consistent
struct { /* pollfd array */
struct pollfd *items;
int capacity;
int length;
} fds;
list_t *items; /* event_item list */
// Timer list
list_t *timers;
} event_loop;
void add_timer(timer_t timer,
void(*cb)(timer_t timer, void *data),
void *data) {
struct timer_item *item = malloc(sizeof(struct timer_item));
item->timer = timer;
item->cb = cb;
item->data = data;
list_add(event_loop.timers, item);
}
void add_event(int fd, short mask,
void(*cb)(int fd, short mask, void *data), void *data) {
struct pollfd pollfd = {
fd,
mask,
0,
};
// Resize
if (event_loop.fds.length == event_loop.fds.capacity) {
event_loop.fds.capacity += 10;
event_loop.fds.items = realloc(event_loop.fds.items,
sizeof(struct pollfd) * event_loop.fds.capacity);
}
event_loop.fds.items[event_loop.fds.length++] = pollfd;
struct event_item *item = malloc(sizeof(struct event_item));
item->cb = cb;
item->data = data;
list_add(event_loop.items, item);
return;
}
bool remove_event(int fd) {
/*
* Instead of removing events immediately, we mark them for deletion
* and clean them up later. This is so we can call remove_event inside
* an event callback safely.
*/
for (int i = 0; i < event_loop.fds.length; ++i) {
if (event_loop.fds.items[i].fd == fd) {
event_loop.fds.items[i].fd = -1;
return true;
}
}
return false;
}
static int timer_item_timer_cmp(const void *_timer_item, const void *_timer) {
const struct timer_item *timer_item = _timer_item;
const timer_t *timer = _timer;
if (timer_item->timer == *timer) {
return 0;
} else {
return -1;
}
}
bool remove_timer(timer_t timer) {
int index = list_seq_find(event_loop.timers, timer_item_timer_cmp, &timer);
if (index != -1) {
free(event_loop.timers->items[index]);
list_del(event_loop.timers, index);
return true;
}
return false;
}
void event_loop_poll(void) {
poll(event_loop.fds.items, event_loop.fds.length, -1);
for (int i = 0; i < event_loop.fds.length; ++i) {
struct pollfd pfd = event_loop.fds.items[i];
struct event_item *item = (struct event_item *)event_loop.items->items[i];
// Always send these events
unsigned events = pfd.events | POLLHUP | POLLERR;
if (pfd.revents & events) {
item->cb(pfd.fd, pfd.revents, item->data);
}
}
// Cleanup removed events
int end = 0;
int length = event_loop.fds.length;
for (int i = 0; i < length; ++i) {
if (event_loop.fds.items[i].fd == -1) {
free(event_loop.items->items[i]);
list_del(event_loop.items, i);
--event_loop.fds.length;
} else if (end != i) {
event_loop.fds.items[end++] = event_loop.fds.items[i];
} else {
end = i + 1;
}
}
// check timers
// not tested, but seems to work
for (int i = 0; i < event_loop.timers->length; ++i) {
struct timer_item *item = event_loop.timers->items[i];
int overrun = timer_getoverrun(item->timer);
if (overrun && overrun != -1) {
item->cb(item->timer, item->data);
}
}
}
void init_event_loop(void) {
event_loop.fds.length = 0;
event_loop.fds.capacity = 10;
event_loop.fds.items = malloc(
event_loop.fds.capacity * sizeof(struct pollfd));
event_loop.items = create_list();
event_loop.timers = create_list();
}

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@ -2,7 +2,6 @@ executable(
'swaybar', [ 'swaybar', [
'bar.c', 'bar.c',
'config.c', 'config.c',
'event_loop.c',
'i3bar.c', 'i3bar.c',
'ipc.c', 'ipc.c',
'main.c', 'main.c',

View file

@ -7,16 +7,16 @@
#include <stdio.h> #include <stdio.h>
#include <unistd.h> #include <unistd.h>
#include <wlr/util/log.h> #include <wlr/util/log.h>
#include "loop.h"
#include "swaybar/bar.h" #include "swaybar/bar.h"
#include "swaybar/config.h" #include "swaybar/config.h"
#include "swaybar/i3bar.h" #include "swaybar/i3bar.h"
#include "swaybar/event_loop.h"
#include "swaybar/status_line.h" #include "swaybar/status_line.h"
#include "readline.h" #include "readline.h"
static void status_line_close_fds(struct status_line *status) { static void status_line_close_fds(struct status_line *status) {
if (status->read_fd != -1) { if (status->read_fd != -1) {
remove_event(status->read_fd); loop_remove_event(status->bar->eventloop, status->bar->status_event);
close(status->read_fd); close(status->read_fd);
status->read_fd = -1; status->read_fd = -1;
} }