1 files changed, 180 insertions, 0 deletions

diff --git a/common/loop.c b/common/loop.c
new file mode 100644
index 00000000..750bee75
--- /dev/null
+++ b/common/loop.c
@@ -0,0 +1,180 @@
+#define _POSIX_C_SOURCE 199309L
+#include <limits.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <poll.h>
+#include <time.h>
+#include <unistd.h>
+#include "list.h"
+#include "log.h"
+#include "loop.h"
+
+struct loop_fd_event {
+        void (*callback)(int fd, short mask, void *data);
+        void *data;
+};
+
+struct loop_timer {
+        void (*callback)(void *data);
+        void *data;
+        struct timespec expiry;
+};
+
+struct loop {
+        struct pollfd *fds;
+        int fd_length;
+        int fd_capacity;
+
+        list_t *fd_events; // struct loop_fd_event
+        list_t *timers; // struct loop_timer
+};
+
+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->fd_events = create_list();
+        loop->timers = create_list();
+        return loop;
+}
+
+void loop_destroy(struct loop *loop) {
+        list_foreach(loop->fd_events, free);
+        list_foreach(loop->timers, free);
+        list_free(loop->fd_events);
+        list_free(loop->timers);
+        free(loop->fds);
+        free(loop);
+}
+
+void loop_poll(struct loop *loop) {
+        // Calculate next timer in ms
+        int ms = INT_MAX;
+        if (loop->timers->length) {
+                struct timespec now;
+                clock_gettime(CLOCK_MONOTONIC, &now);
+                for (int i = 0; i < loop->timers->length; ++i) {
+                        struct loop_timer *timer = loop->timers->items[i];
+                        int timer_ms = (timer->expiry.tv_sec - now.tv_sec) * 1000;
+                        timer_ms += (timer->expiry.tv_nsec - now.tv_nsec) / 1000000;
+                        if (timer_ms < ms) {
+                                ms = timer_ms;
+                        }
+                }
+        }
+        if (ms < 0) {
+                ms = 0;
+        }
+
+        poll(loop->fds, loop->fd_length, ms);
+
+        // Dispatch fds
+        for (int i = 0; i < loop->fd_length; ++i) {
+                struct pollfd pfd = loop->fds[i];
+                struct loop_fd_event *event = loop->fd_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);
+                }
+        }
+
+        // Dispatch timers
+        if (loop->timers->length) {
+                struct timespec now;
+                clock_gettime(CLOCK_MONOTONIC, &now);
+                for (int i = 0; i < loop->timers->length; ++i) {
+                        struct loop_timer *timer = loop->timers->items[i];
+                        bool expired = timer->expiry.tv_sec < now.tv_sec ||
+                                (timer->expiry.tv_sec == now.tv_sec &&
+                                 timer->expiry.tv_nsec < now.tv_nsec);
+                        if (expired) {
+                                timer->callback(timer->data);
+                                loop_remove_timer(loop, timer);
+                                --i;
+                        }
+                }
+        }
+}
+
+void loop_add_fd(struct loop *loop, int fd, short mask,
+                void (*callback)(int fd, short mask, void *data), void *data) {
+        struct loop_fd_event *event = calloc(1, sizeof(struct loop_fd_event));
+        if (!event) {
+                wlr_log(WLR_ERROR, "Unable to allocate memory for event");
+                return;
+        }
+        event->callback = callback;
+        event->data = data;
+        list_add(loop->fd_events, event);
+
+        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_timer *loop_add_timer(struct loop *loop, int ms,
+                void (*callback)(void *data), void *data) {
+        struct loop_timer *timer = calloc(1, sizeof(struct loop_timer));
+        if (!timer) {
+                wlr_log(WLR_ERROR, "Unable to allocate memory for timer");
+                return NULL;
+        }
+        timer->callback = callback;
+        timer->data = data;
+
+        clock_gettime(CLOCK_MONOTONIC, &timer->expiry);
+        timer->expiry.tv_sec += ms / 1000;
+
+        long int nsec = (ms % 1000) * 1000000;
+        if (timer->expiry.tv_nsec + nsec >= 1000000000) {
+                timer->expiry.tv_sec++;
+                nsec -= 1000000000;
+        }
+        timer->expiry.tv_nsec += nsec;
+
+        list_add(loop->timers, timer);
+
+        return timer;
+}
+
+bool loop_remove_fd(struct loop *loop, int fd) {
+        for (int i = 0; i < loop->fd_length; ++i) {
+                if (loop->fds[i].fd == fd) {
+                        free(loop->fd_events->items[i]);
+                        list_del(loop->fd_events, i);
+
+                        loop->fd_length--;
+                        memmove(&loop->fds[i], &loop->fds[i + 1],
+                                        sizeof(struct pollfd) * (loop->fd_length - i));
+
+                        return true;
+                }
+        }
+        return false;
+}
+
+bool loop_remove_timer(struct loop *loop, struct loop_timer *timer) {
+        for (int i = 0; i < loop->timers->length; ++i) {
+                if (loop->timers->items[i] == timer) {
+                        list_del(loop->timers, i);
+                        free(timer);
+                        return true;
+                }
+        }
+        return false;
+}