1 files changed, 429 insertions, 0 deletions

diff --git a/src/platform/posix/loop.c b/src/platform/posix/loop.c
new file mode 100644
index 0000000..88454d8
--- /dev/null
+++ b/src/platform/posix/loop.c
@@ -0,0 +1,429 @@
+#define _GNU_SOURCE
+#define _POSIX_C_SOURCE 200809L
+#include "common/loop.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#define YASL_LOOP_INIT_CAP 32
+
+typedef int (*yasl_loop_fd_fn)(int fd, short revents, void *ud);
+
+struct yasl_fd_source {
+    yasl_loop_fd_fn fn;
+    void *ud;
+    int id;
+    int fd;
+    short events;
+};
+
+struct yasl_timer_source {
+    yasl_timer_cb fn;
+    void *ud;
+    uint64_t interval_ns;
+    uint64_t deadline_ns;
+    yasl_timer_id id;
+    bool deleted;
+};
+
+struct yasl_loop {
+    struct yasl_fd_source *fds;
+    struct pollfd *pollfds;
+    int count;
+    int capacity;
+    int next_id;
+    bool running;
+    int wake_rfd;
+    int wake_wfd;
+    int wake_watch;
+
+    struct yasl_timer_source *timers;
+    int timer_count;
+    int timer_capacity;
+    uint32_t next_timer_id;
+    int timer_firing_depth;
+};
+
+uint64_t yasl_loop_now_ns(void)
+{
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return (uint64_t)ts.tv_sec * 1000000000ull + (uint64_t)ts.tv_nsec;
+}
+
+static int loop_wake_cb(int fd, short revents, void *ud)
+{
+    (void)revents;
+    (void)ud;
+    char buf[128];
+    ssize_t n;
+    while ((n = read(fd, buf, sizeof(buf))) > 0 || (n < 0 && errno == EINTR)) {}
+    return 0;
+}
+
+struct yasl_loop *yasl_loop_create(void)
+{
+    struct yasl_loop *l = calloc(1, sizeof(*l));
+    if (!l) return NULL;
+
+    l->capacity = YASL_LOOP_INIT_CAP;
+    l->fds = malloc((size_t)l->capacity * sizeof(*l->fds));
+    l->pollfds = malloc((size_t)l->capacity * sizeof(*l->pollfds));
+    if (!l->fds || !l->pollfds) {
+        free(l->fds);
+        free(l->pollfds);
+        free(l);
+        return NULL;
+    }
+
+    l->next_id = 1;
+    l->next_timer_id = 1;
+    l->wake_rfd = -1;
+    l->wake_wfd = -1;
+
+    int p[2];
+#if defined(__linux__) && defined(O_CLOEXEC)
+    if (pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0) {
+        l->wake_rfd = p[0];
+        l->wake_wfd = p[1];
+    }
+#else
+    if (pipe(p) == 0) {
+        int f0 = fcntl(p[0], F_GETFL, 0);
+        int f1 = fcntl(p[1], F_GETFL, 0);
+        if (f0 >= 0) fcntl(p[0], F_SETFL, f0 | O_NONBLOCK);
+        if (f1 >= 0) fcntl(p[1], F_SETFL, f1 | O_NONBLOCK);
+        fcntl(p[0], F_SETFD, FD_CLOEXEC);
+        fcntl(p[1], F_SETFD, FD_CLOEXEC);
+        l->wake_rfd = p[0];
+        l->wake_wfd = p[1];
+    }
+#endif
+
+    if (l->wake_rfd >= 0) {
+        l->wake_watch = yasl_loop_add_fd(l, l->wake_rfd, POLLIN, loop_wake_cb, l);
+    }
+    return l;
+}
+
+void yasl_loop_destroy(struct yasl_loop *l)
+{
+    if (!l) return;
+    if (l->wake_watch > 0)
+        yasl_loop_del_fd(l, l->wake_watch);
+    if (l->wake_rfd >= 0)
+        close(l->wake_rfd);
+    if (l->wake_wfd >= 0)
+        close(l->wake_wfd);
+    free(l->fds);
+    free(l->pollfds);
+    free(l->timers);
+    free(l);
+}
+
+int yasl_loop_add_fd(struct yasl_loop *l, int fd, short events,
+                     int (*fn)(int fd, short revents, void *ud), void *ud)
+{
+    if (!l || fd < 0)
+        return -1;
+
+    if (l->count >= l->capacity) {
+        int new_cap = l->capacity ? l->capacity * 2 : YASL_LOOP_INIT_CAP;
+        struct yasl_fd_source *new_fds = realloc(l->fds, (size_t)new_cap * sizeof(*new_fds));
+        if (!new_fds) return -1;
+        l->fds = new_fds;
+
+        struct pollfd *new_pollfds = realloc(l->pollfds, (size_t)new_cap * sizeof(*new_pollfds));
+        if (!new_pollfds) return -1;
+        l->pollfds = new_pollfds;
+        l->capacity = new_cap;
+    }
+
+    int id = l->next_id++;
+    if (l->next_id <= 0) l->next_id = 1;
+
+    l->fds[l->count] = (struct yasl_fd_source){
+        .fn = fn, .ud = ud, .id = id, .fd = fd, .events = events,
+    };
+    l->pollfds[l->count] = (struct pollfd){
+        .fd = fd, .events = events, .revents = 0,
+    };
+    l->count++;
+    return id;
+}
+
+int yasl_loop_del_fd(struct yasl_loop *l, int id)
+{
+    if (!l || id <= 0) return -1;
+    for (int i = 0; i < l->count; i++) {
+        if (l->fds[i].id == id) {
+            l->count--;
+            l->fds[i] = l->fds[l->count];
+            l->pollfds[i] = l->pollfds[l->count];
+            return 0;
+        }
+    }
+    return -1;
+}
+
+int yasl_loop_set_fd_events(struct yasl_loop *l, int id, short events)
+{
+    if (!l || id <= 0) return -1;
+    for (int i = 0; i < l->count; i++) {
+        if (l->fds[i].id == id) {
+            l->fds[i].events = events;
+            l->pollfds[i].events = events;
+            return 0;
+        }
+    }
+    return -1;
+}
+
+void yasl_loop_kick(struct yasl_loop *l)
+{
+    if (!l || l->wake_wfd < 0) return;
+    char b = 1;
+    ssize_t n;
+    do {
+        n = write(l->wake_wfd, &b, 1);
+    } while (n < 0 && errno == EINTR);
+}
+
+static void timer_cleanup_deleted(struct yasl_loop *l)
+{
+    if (!l || l->timer_firing_depth > 0) return;
+    int dest = 0;
+    for (int src = 0; src < l->timer_count; src++) {
+        struct yasl_timer_source t = l->timers[src];
+        l->timers[dest] = t;
+        dest += !t.deleted;
+    }
+    l->timer_count = dest;
+}
+
+bool yasl_loop_timer_armed(const struct yasl_loop *l, yasl_timer_id id)
+{
+    if (!l || id == 0) return false;
+    for (int i = 0; i < l->timer_count; i++)
+        if (l->timers[i].id == id)
+            return !l->timers[i].deleted;
+    return false;
+}
+
+int yasl_loop_next_timeout_ms(const struct yasl_loop *l)
+{
+    if (!l || l->timer_count <= 0) return -1;
+    uint64_t now = yasl_loop_now_ns();
+    uint64_t min_deadline = UINT64_MAX;
+    bool has_active = false;
+    for (int i = 0; i < l->timer_count; i++) {
+        if (!l->timers[i].deleted) {
+            has_active = true;
+            if (l->timers[i].deadline_ns < min_deadline)
+                min_deadline = l->timers[i].deadline_ns;
+        }
+    }
+    if (!has_active) return -1;
+    if (min_deadline <= now) return 0;
+    uint64_t diff = min_deadline - now;
+    uint64_t ms = (diff + 999999ull) / 1000000ull;
+    return (ms > (uint64_t)INT_MAX) ? INT_MAX : (int)ms;
+}
+
+yasl_timer_id yasl_loop_add_timer(struct yasl_loop *l, uint64_t interval_ns,
+                                  yasl_timer_cb cb, void *ud)
+{
+    if (!l || !cb || interval_ns == 0) return 0;
+
+    if (l->timer_count >= l->timer_capacity) {
+        int new_cap = l->timer_capacity ? l->timer_capacity * 2 : 16;
+        struct yasl_timer_source *new_timers = realloc(l->timers, (size_t)new_cap * sizeof(*new_timers));
+        if (!new_timers) return 0;
+        l->timers = new_timers;
+        l->timer_capacity = new_cap;
+    }
+
+    uint32_t id = l->next_timer_id++;
+    if (l->next_timer_id == 0) l->next_timer_id = 1;
+
+    uint64_t now = yasl_loop_now_ns();
+    l->timers[l->timer_count++] = (struct yasl_timer_source){
+        .fn = cb,
+        .ud = ud,
+        .id = id,
+        .interval_ns = interval_ns,
+        .deadline_ns = now + interval_ns,
+        .deleted = false,
+    };
+
+    yasl_loop_kick(l);
+    return id;
+}
+
+bool yasl_loop_del_timer(struct yasl_loop *l, yasl_timer_id id)
+{
+    if (!l || id == 0) return false;
+    for (int i = l->timer_count - 1; i >= 0; i--) {
+        if (l->timers[i].id == id && !l->timers[i].deleted) {
+            l->timers[i].deleted = true;
+            if (l->timer_firing_depth == 0) {
+                if (i == l->timer_count - 1) {
+                    while (l->timer_count > 0 && l->timers[l->timer_count - 1].deleted)
+                        l->timer_count--;
+                } else {
+                    timer_cleanup_deleted(l);
+                }
+            }
+            return true;
+        }
+    }
+    return false;
+}
+
+int yasl_loop_step(struct yasl_loop *l, int timeout_ms)
+{
+    if (!l) return -1;
+
+    int timer_to = yasl_loop_next_timeout_ms(l);
+    int effective_timeout = timeout_ms;
+    if (timer_to >= 0) {
+        if (effective_timeout < 0 || timer_to < effective_timeout)
+            effective_timeout = timer_to;
+    }
+
+    if (l->count <= 0) {
+        if (effective_timeout > 0) {
+            struct timespec req = {
+                .tv_sec = effective_timeout / 1000,
+                .tv_nsec = (long)(effective_timeout % 1000) * 1000000L,
+            };
+            nanosleep(&req, NULL);
+        }
+    } else {
+        int n;
+        do {
+            n = poll(l->pollfds, (nfds_t)l->count, effective_timeout);
+        } while (n < 0 && errno == EINTR);
+
+        if (n < 0) return -1;
+    }
+
+    int handled = 0;
+
+    if (l->count > 0) {
+        int count = l->count;
+        struct yasl_fd_source sstack[32];
+        struct pollfd pstack[32];
+        struct yasl_fd_source *scopy = (count <= 32) ? sstack : malloc((size_t)count * sizeof(*scopy));
+        struct pollfd *pcopy = (count <= 32) ? pstack : malloc((size_t)count * sizeof(*pcopy));
+        if (!scopy || !pcopy) {
+            if (scopy && scopy != sstack) free(scopy);
+            if (pcopy && pcopy != pstack) free(pcopy);
+            return -1;
+        }
+
+        memcpy(scopy, l->fds, (size_t)count * sizeof(*scopy));
+        memcpy(pcopy, l->pollfds, (size_t)count * sizeof(*pcopy));
+
+        for (int i = 0; i < count; i++) {
+            if (pcopy[i].revents) {
+                short revents = pcopy[i].revents;
+                // Fast-path: check if source is still at index i before linear scan
+                bool valid = false;
+                if (i < l->count && l->fds[i].id == scopy[i].id) {
+                    l->pollfds[i].revents = 0;
+                    valid = true;
+                } else {
+                    for (int j = 0; j < l->count; j++) {
+                        if (l->fds[j].id == scopy[i].id) {
+                            l->pollfds[j].revents = 0;
+                            valid = true;
+                            break;
+                        }
+                    }
+                }
+                if (valid && scopy[i].fn) {
+                    scopy[i].fn(scopy[i].fd, revents, scopy[i].ud);
+                    handled++;
+                }
+            }
+        }
+
+        if (scopy != sstack) free(scopy);
+        if (pcopy != pstack) free(pcopy);
+    }
+
+    if (l->timer_count > 0) {
+        uint64_t now = yasl_loop_now_ns();
+        l->timer_firing_depth++;
+        int initial_count = l->timer_count;
+        for (int i = 0; i < initial_count; i++) {
+            if (i >= l->timer_count) break;
+            if (l->timers[i].deleted || l->timers[i].deadline_ns > now)
+                continue;
+
+            yasl_timer_id tid = l->timers[i].id;
+            uint64_t interval = l->timers[i].interval_ns;
+            void *ud = l->timers[i].ud;
+            struct yasl_timer_source timer_src = l->timers[i];
+
+            uint64_t next_interval = timer_src.fn(ud, tid, interval);
+            handled++;
+
+            // Fast-path: timer is usually still at index i unless an earlier timer was deleted
+            if (i < l->timer_count && l->timers[i].id == tid) {
+                if (next_interval == 0 || l->timers[i].deleted) {
+                    l->timers[i].deleted = true;
+                } else {
+                    l->timers[i].interval_ns = next_interval;
+                    if (l->timers[i].deadline_ns + next_interval > now)
+                        l->timers[i].deadline_ns += next_interval;
+                    else
+                        l->timers[i].deadline_ns = now + next_interval;
+                }
+            } else {
+                for (int j = 0; j < l->timer_count; j++) {
+                    if (l->timers[j].id == tid) {
+                        if (next_interval == 0 || l->timers[j].deleted) {
+                            l->timers[j].deleted = true;
+                        } else {
+                            l->timers[j].interval_ns = next_interval;
+                            if (l->timers[j].deadline_ns + next_interval > now)
+                                l->timers[j].deadline_ns += next_interval;
+                            else
+                                l->timers[j].deadline_ns = now + next_interval;
+                        }
+                        break;
+                    }
+                }
+            }
+        }
+        l->timer_firing_depth--;
+        if (l->timer_firing_depth == 0) {
+            timer_cleanup_deleted(l);
+        }
+    }
+
+    return handled;
+}
+
+int yasl_loop_run(struct yasl_loop *l)
+{
+    if (!l) return -1;
+    l->running = true;
+    while (l->running) {
+        if (yasl_loop_step(l, -1) < 0)
+            return -1;
+    }
+    return 0;
+}
+
+void yasl_loop_quit(struct yasl_loop *l)
+{
+    if (l) l->running = false;
+}