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-rw-r--r--sysdep/unix/io-loop.c537
1 files changed, 537 insertions, 0 deletions
diff --git a/sysdep/unix/io-loop.c b/sysdep/unix/io-loop.c
new file mode 100644
index 00000000..dfb2ce49
--- /dev/null
+++ b/sysdep/unix/io-loop.c
@@ -0,0 +1,537 @@
+/*
+ * BIRD -- I/O and event loop
+ *
+ * Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <pthread.h>
+#include <time.h>
+#include <sys/time.h>
+
+#include "nest/bird.h"
+
+#include "lib/buffer.h"
+#include "lib/coro.h"
+#include "lib/lists.h"
+#include "lib/resource.h"
+#include "lib/event.h"
+#include "lib/timer.h"
+#include "lib/socket.h"
+
+#include "lib/io-loop.h"
+#include "sysdep/unix/io-loop.h"
+#include "conf/conf.h"
+
+/*
+ * Current thread context
+ */
+
+_Thread_local struct birdloop *birdloop_current;
+static _Thread_local struct birdloop *birdloop_wakeup_masked;
+static _Thread_local uint birdloop_wakeup_masked_count;
+
+event_list *
+birdloop_event_list(struct birdloop *loop)
+{
+ return &loop->event_list;
+}
+
+struct timeloop *
+birdloop_time_loop(struct birdloop *loop)
+{
+ return &loop->time;
+}
+
+_Bool
+birdloop_inside(struct birdloop *loop)
+{
+ for (struct birdloop *c = birdloop_current; c; c = c->prev_loop)
+ if (loop == c)
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Wakeup code for birdloop
+ */
+
+static void
+pipe_new(int *pfds)
+{
+ int rv = pipe(pfds);
+ if (rv < 0)
+ die("pipe: %m");
+
+ if (fcntl(pfds[0], F_SETFL, O_NONBLOCK) < 0)
+ die("fcntl(O_NONBLOCK): %m");
+
+ if (fcntl(pfds[1], F_SETFL, O_NONBLOCK) < 0)
+ die("fcntl(O_NONBLOCK): %m");
+}
+
+void
+pipe_drain(int fd)
+{
+ char buf[64];
+ int rv;
+
+ try:
+ rv = read(fd, buf, 64);
+ if (rv < 0)
+ {
+ if (errno == EINTR)
+ goto try;
+ if (errno == EAGAIN)
+ return;
+ die("wakeup read: %m");
+ }
+ if (rv == 64)
+ goto try;
+}
+
+void
+pipe_kick(int fd)
+{
+ u64 v = 1;
+ int rv;
+
+ try:
+ rv = write(fd, &v, sizeof(u64));
+ if (rv < 0)
+ {
+ if (errno == EINTR)
+ goto try;
+ if (errno == EAGAIN)
+ return;
+ die("wakeup write: %m");
+ }
+}
+
+static inline void
+wakeup_init(struct birdloop *loop)
+{
+ pipe_new(loop->wakeup_fds);
+}
+
+static inline void
+wakeup_drain(struct birdloop *loop)
+{
+ pipe_drain(loop->wakeup_fds[0]);
+}
+
+static inline void
+wakeup_do_kick(struct birdloop *loop)
+{
+ pipe_kick(loop->wakeup_fds[1]);
+}
+
+void
+birdloop_ping(struct birdloop *loop)
+{
+ u32 ping_sent = atomic_fetch_add_explicit(&loop->ping_sent, 1, memory_order_acq_rel);
+ if (ping_sent)
+ return;
+
+ if (loop == birdloop_wakeup_masked)
+ birdloop_wakeup_masked_count++;
+ else
+ wakeup_do_kick(loop);
+}
+
+
+/*
+ * Sockets
+ */
+
+static void
+sockets_init(struct birdloop *loop)
+{
+ init_list(&loop->sock_list);
+ loop->sock_num = 0;
+
+ BUFFER_INIT(loop->poll_sk, loop->pool, 4);
+ BUFFER_INIT(loop->poll_fd, loop->pool, 4);
+ loop->poll_changed = 1; /* add wakeup fd */
+}
+
+static void
+sockets_add(struct birdloop *loop, sock *s)
+{
+ add_tail(&loop->sock_list, &s->n);
+ loop->sock_num++;
+
+ s->index = -1;
+ loop->poll_changed = 1;
+
+ birdloop_ping(loop);
+}
+
+void
+sk_start(sock *s)
+{
+ ASSERT_DIE(birdloop_current != &main_birdloop);
+ sockets_add(birdloop_current, s);
+}
+
+static void
+sockets_remove(struct birdloop *loop, sock *s)
+{
+ rem_node(&s->n);
+ loop->sock_num--;
+
+ if (s->index >= 0)
+ {
+ loop->poll_sk.data[s->index] = NULL;
+ s->index = -1;
+ loop->poll_changed = 1;
+ loop->close_scheduled = 1;
+ birdloop_ping(loop);
+ }
+ else
+ close(s->fd);
+}
+
+void
+sk_stop(sock *s)
+{
+ sockets_remove(birdloop_current, s);
+}
+
+static inline uint sk_want_events(sock *s)
+{ return (s->rx_hook ? POLLIN : 0) | ((s->ttx != s->tpos) ? POLLOUT : 0); }
+
+/*
+FIXME: this should be called from sock code
+
+static void
+sockets_update(struct birdloop *loop, sock *s)
+{
+ if (s->index >= 0)
+ loop->poll_fd.data[s->index].events = sk_want_events(s);
+}
+*/
+
+static void
+sockets_prepare(struct birdloop *loop)
+{
+ BUFFER_SET(loop->poll_sk, loop->sock_num + 1);
+ BUFFER_SET(loop->poll_fd, loop->sock_num + 1);
+
+ struct pollfd *pfd = loop->poll_fd.data;
+ sock **psk = loop->poll_sk.data;
+ uint i = 0;
+ node *n;
+
+ WALK_LIST(n, loop->sock_list)
+ {
+ sock *s = SKIP_BACK(sock, n, n);
+
+ ASSERT(i < loop->sock_num);
+
+ s->index = i;
+ *psk = s;
+ pfd->fd = s->fd;
+ pfd->events = sk_want_events(s);
+ pfd->revents = 0;
+
+ pfd++;
+ psk++;
+ i++;
+ }
+
+ ASSERT(i == loop->sock_num);
+
+ /* Add internal wakeup fd */
+ *psk = NULL;
+ pfd->fd = loop->wakeup_fds[0];
+ pfd->events = POLLIN;
+ pfd->revents = 0;
+
+ loop->poll_changed = 0;
+}
+
+static void
+sockets_close_fds(struct birdloop *loop)
+{
+ struct pollfd *pfd = loop->poll_fd.data;
+ sock **psk = loop->poll_sk.data;
+ int poll_num = loop->poll_fd.used - 1;
+
+ int i;
+ for (i = 0; i < poll_num; i++)
+ if (psk[i] == NULL)
+ close(pfd[i].fd);
+
+ loop->close_scheduled = 0;
+}
+
+int sk_read(sock *s, int revents);
+int sk_write(sock *s);
+
+static void
+sockets_fire(struct birdloop *loop)
+{
+ struct pollfd *pfd = loop->poll_fd.data;
+ sock **psk = loop->poll_sk.data;
+ int poll_num = loop->poll_fd.used - 1;
+
+ times_update();
+
+ /* Last fd is internal wakeup fd */
+ if (pfd[poll_num].revents & POLLIN)
+ wakeup_drain(loop);
+
+ int i;
+ for (i = 0; i < poll_num; pfd++, psk++, i++)
+ {
+ int e = 1;
+
+ if (! pfd->revents)
+ continue;
+
+ if (pfd->revents & POLLNVAL)
+ die("poll: invalid fd %d", pfd->fd);
+
+ if (pfd->revents & POLLIN)
+ while (e && *psk && (*psk)->rx_hook)
+ e = sk_read(*psk, pfd->revents);
+
+ e = 1;
+ if (pfd->revents & POLLOUT)
+ {
+ loop->poll_changed = 1;
+ while (e && *psk)
+ e = sk_write(*psk);
+ }
+ }
+}
+
+
+/*
+ * Birdloop
+ */
+
+struct birdloop main_birdloop;
+
+static void birdloop_enter_locked(struct birdloop *loop);
+
+void
+birdloop_init(void)
+{
+ wakeup_init(&main_birdloop);
+
+ main_birdloop.time.domain = the_bird_domain.the_bird;
+ main_birdloop.time.loop = &main_birdloop;
+
+ times_update();
+ timers_init(&main_birdloop.time, &root_pool);
+
+ birdloop_enter_locked(&main_birdloop);
+}
+
+static void birdloop_main(void *arg);
+
+struct birdloop *
+birdloop_new(pool *pp, uint order, const char *name)
+{
+ struct domain_generic *dg = domain_new(name, order);
+
+ pool *p = rp_new(pp, name);
+ struct birdloop *loop = mb_allocz(p, sizeof(struct birdloop));
+ loop->pool = p;
+
+ loop->time.domain = dg;
+ loop->time.loop = loop;
+
+ birdloop_enter(loop);
+
+ wakeup_init(loop);
+ ev_init_list(&loop->event_list, loop, name);
+ timers_init(&loop->time, p);
+ sockets_init(loop);
+
+ loop->time.coro = coro_run(p, birdloop_main, loop);
+
+ birdloop_leave(loop);
+
+ return loop;
+}
+
+static void
+birdloop_do_stop(struct birdloop *loop, void (*stopped)(void *data), void *data)
+{
+ loop->stopped = stopped;
+ loop->stop_data = data;
+ wakeup_do_kick(loop);
+}
+
+void
+birdloop_stop(struct birdloop *loop, void (*stopped)(void *data), void *data)
+{
+ DG_LOCK(loop->time.domain);
+ birdloop_do_stop(loop, stopped, data);
+ DG_UNLOCK(loop->time.domain);
+}
+
+void
+birdloop_stop_self(struct birdloop *loop, void (*stopped)(void *data), void *data)
+{
+ ASSERT_DIE(loop == birdloop_current);
+ ASSERT_DIE(DG_IS_LOCKED(loop->time.domain));
+
+ birdloop_do_stop(loop, stopped, data);
+}
+
+void
+birdloop_free(struct birdloop *loop)
+{
+ ASSERT_DIE(loop->links == 0);
+ domain_free(loop->time.domain);
+ rfree(loop->pool);
+}
+
+static void
+birdloop_enter_locked(struct birdloop *loop)
+{
+ ASSERT_DIE(DG_IS_LOCKED(loop->time.domain));
+ ASSERT_DIE(!birdloop_inside(loop));
+
+ /* Store the old context */
+ loop->prev_loop = birdloop_current;
+
+ /* Put the new context */
+ birdloop_current = loop;
+}
+
+void
+birdloop_enter(struct birdloop *loop)
+{
+ DG_LOCK(loop->time.domain);
+ return birdloop_enter_locked(loop);
+}
+
+static void
+birdloop_leave_locked(struct birdloop *loop)
+{
+ /* Check the current context */
+ ASSERT_DIE(birdloop_current == loop);
+
+ /* Restore the old context */
+ birdloop_current = loop->prev_loop;
+}
+
+void
+birdloop_leave(struct birdloop *loop)
+{
+ birdloop_leave_locked(loop);
+ DG_UNLOCK(loop->time.domain);
+}
+
+void
+birdloop_mask_wakeups(struct birdloop *loop)
+{
+ ASSERT_DIE(birdloop_wakeup_masked == NULL);
+ birdloop_wakeup_masked = loop;
+}
+
+void
+birdloop_unmask_wakeups(struct birdloop *loop)
+{
+ ASSERT_DIE(birdloop_wakeup_masked == loop);
+ birdloop_wakeup_masked = NULL;
+ if (birdloop_wakeup_masked_count)
+ wakeup_do_kick(loop);
+
+ birdloop_wakeup_masked_count = 0;
+}
+
+void
+birdloop_link(struct birdloop *loop)
+{
+ ASSERT_DIE(birdloop_inside(loop));
+ loop->links++;
+}
+
+void
+birdloop_unlink(struct birdloop *loop)
+{
+ ASSERT_DIE(birdloop_inside(loop));
+ loop->links--;
+}
+
+static void
+birdloop_main(void *arg)
+{
+ struct birdloop *loop = arg;
+ timer *t;
+ int rv, timeout;
+
+ btime loop_begin = current_time();
+
+ tmp_init(loop->pool);
+
+ birdloop_enter(loop);
+ while (1)
+ {
+ timers_fire(&loop->time, 0);
+ if (ev_run_list(&loop->event_list))
+ timeout = 0;
+ else if (t = timers_first(&loop->time))
+ timeout = (tm_remains(t) TO_MS) + 1;
+ else
+ timeout = -1;
+
+ if (loop->poll_changed)
+ sockets_prepare(loop);
+
+ btime duration = current_time() - loop_begin;
+ if (duration > config->watchdog_warning)
+ log(L_WARN "I/O loop cycle took %d ms", (int) (duration TO_MS));
+
+ birdloop_leave(loop);
+
+ try:
+ rv = poll(loop->poll_fd.data, loop->poll_fd.used, timeout);
+ if (rv < 0)
+ {
+ if (errno == EINTR || errno == EAGAIN)
+ goto try;
+ die("poll: %m");
+ }
+
+ birdloop_enter(loop);
+
+ if (loop->close_scheduled)
+ sockets_close_fds(loop);
+
+ if (loop->stopped)
+ break;
+
+ loop_begin = current_time();
+
+ if (rv)
+ sockets_fire(loop);
+
+ atomic_exchange_explicit(&loop->ping_sent, 0, memory_order_acq_rel);
+ }
+
+ /* Flush remaining events */
+ ASSERT_DIE(!ev_run_list(&loop->event_list));
+
+ /* No timers allowed */
+ ASSERT_DIE(timers_count(&loop->time) == 0);
+ ASSERT_DIE(EMPTY_LIST(loop->sock_list));
+ ASSERT_DIE(loop->sock_num == 0);
+
+ birdloop_leave(loop);
+ loop->stopped(loop->stop_data);
+}
+
+