1 files changed, 335 insertions, 0 deletions
diff --git a/src/ev_select.c b/src/ev_select.c
new file mode 100644
index 0000000..eadd588
--- /dev/null
+++ b/src/ev_select.c
@@ -0,0 +1,335 @@
+/*
+ * FD polling functions for generic select()
+ *
+ * Copyright 2000-2014 Willy Tarreau <w@1wt.eu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include <haproxy/activity.h>
+#include <haproxy/api.h>
+#include <haproxy/clock.h>
+#include <haproxy/fd.h>
+#include <haproxy/global.h>
+#include <haproxy/task.h>
+#include <haproxy/ticks.h>
+
+
+/* private data */
+static int maxfd;   /* # of the highest fd + 1 */
+static unsigned int *fd_evts[2];
+static THREAD_LOCAL fd_set *tmp_evts[2];
+
+/* Immediately remove the entry upon close() */
+static void __fd_clo(int fd)
+{
+	hap_fd_clr(fd, fd_evts[DIR_RD]);
+	hap_fd_clr(fd, fd_evts[DIR_WR]);
+}
+
+static void _update_fd(int fd, int *max_add_fd)
+{
+	int en;
+	ulong pr, ps;
+
+	en = fdtab[fd].state;
+	pr = _HA_ATOMIC_LOAD(&polled_mask[fd].poll_recv);
+	ps = _HA_ATOMIC_LOAD(&polled_mask[fd].poll_send);
+
+	/* we have a single state for all threads, which is why we
+	 * don't check the tid_bit. First thread to see the update
+	 * takes it for every other one.
+	 */
+	if (!(en & FD_EV_ACTIVE_RW)) {
+		if (!(pr | ps)) {
+			/* fd was not watched, it's still not */
+			return;
+		}
+		/* fd totally removed from poll list */
+		hap_fd_clr(fd, fd_evts[DIR_RD]);
+		hap_fd_clr(fd, fd_evts[DIR_WR]);
+		_HA_ATOMIC_AND(&polled_mask[fd].poll_recv, 0);
+		_HA_ATOMIC_AND(&polled_mask[fd].poll_send, 0);
+	}
+	else {
+		/* OK fd has to be monitored, it was either added or changed */
+		if (!(en & FD_EV_ACTIVE_R)) {
+			hap_fd_clr(fd, fd_evts[DIR_RD]);
+			if (pr & ti->ltid_bit)
+				_HA_ATOMIC_AND(&polled_mask[fd].poll_recv, ~ti->ltid_bit);
+		} else {
+			hap_fd_set(fd, fd_evts[DIR_RD]);
+			if (!(pr & ti->ltid_bit))
+				_HA_ATOMIC_OR(&polled_mask[fd].poll_recv, ti->ltid_bit);
+		}
+
+		if (!(en & FD_EV_ACTIVE_W)) {
+			hap_fd_clr(fd, fd_evts[DIR_WR]);
+			if (ps & ti->ltid_bit)
+				_HA_ATOMIC_AND(&polled_mask[fd].poll_send, ~ti->ltid_bit);
+		} else {
+			hap_fd_set(fd, fd_evts[DIR_WR]);
+			if (!(ps & ti->ltid_bit))
+				_HA_ATOMIC_OR(&polled_mask[fd].poll_send, ti->ltid_bit);
+		}
+
+		if (fd > *max_add_fd)
+			*max_add_fd = fd;
+	}
+}
+
+/*
+ * Select() poller
+ */
+static void _do_poll(struct poller *p, int exp, int wake)
+{
+	int status;
+	int fd, i;
+	struct timeval delta;
+	int delta_ms;
+	int fds;
+	int updt_idx;
+	char count;
+	int readnotnull, writenotnull;
+	int old_maxfd, new_maxfd, max_add_fd;
+	int old_fd;
+
+	max_add_fd = -1;
+
+	/* first, scan the update list to find changes */
+	for (updt_idx = 0; updt_idx < fd_nbupdt; updt_idx++) {
+		fd = fd_updt[updt_idx];
+
+		_HA_ATOMIC_AND(&fdtab[fd].update_mask, ~ti->ltid_bit);
+		if (!fdtab[fd].owner) {
+			activity[tid].poll_drop_fd++;
+			continue;
+		}
+		_update_fd(fd, &max_add_fd);
+	}
+	/* Now scan the global update list */
+	for (old_fd = fd = update_list[tgid - 1].first; fd != -1; fd = fdtab[fd].update.next) {
+		if (fd == -2) {
+			fd = old_fd;
+			continue;
+		}
+		else if (fd <= -3)
+			fd = -fd -4;
+		if (fd == -1)
+			break;
+		if (fdtab[fd].update_mask & ti->ltid_bit) {
+			/* Cheat a bit, as the state is global to all pollers
+			 * we don't need every thread to take care of the
+			 * update.
+			 */
+			_HA_ATOMIC_AND(&fdtab[fd].update_mask, ~tg->threads_enabled);
+			done_update_polling(fd);
+		} else
+			continue;
+		if (!fdtab[fd].owner)
+			continue;
+		_update_fd(fd, &max_add_fd);
+	}
+
+
+	/* maybe we added at least one fd larger than maxfd */
+	for (old_maxfd = maxfd; old_maxfd <= max_add_fd; ) {
+		if (_HA_ATOMIC_CAS(&maxfd, &old_maxfd, max_add_fd + 1))
+			break;
+	}
+
+	/* maxfd doesn't need to be precise but it needs to cover *all* active
+	 * FDs. Thus we only shrink it if we have such an opportunity. The algo
+	 * is simple : look for the previous used place, try to update maxfd to
+	 * point to it, abort if maxfd changed in the mean time.
+	 */
+	old_maxfd = maxfd;
+	do {
+		new_maxfd = old_maxfd;
+		while (new_maxfd - 1 >= 0 && !fdtab[new_maxfd - 1].owner)
+			new_maxfd--;
+		if (new_maxfd >= old_maxfd)
+			break;
+	} while (!_HA_ATOMIC_CAS(&maxfd, &old_maxfd, new_maxfd));
+
+	thread_idle_now();
+	thread_harmless_now();
+
+	fd_nbupdt = 0;
+
+	/* let's restore fdset state */
+	readnotnull = 0; writenotnull = 0;
+	for (i = 0; i < (maxfd + FD_SETSIZE - 1)/(8*sizeof(int)); i++) {
+		readnotnull |= (*(((int*)tmp_evts[DIR_RD])+i) = *(((int*)fd_evts[DIR_RD])+i)) != 0;
+		writenotnull |= (*(((int*)tmp_evts[DIR_WR])+i) = *(((int*)fd_evts[DIR_WR])+i)) != 0;
+	}
+
+	/* now let's wait for events */
+	delta_ms = wake ? 0 : compute_poll_timeout(exp);
+	delta.tv_sec  = (delta_ms / 1000);
+	delta.tv_usec = (delta_ms % 1000) * 1000;
+	clock_entering_poll();
+	status = select(maxfd,
+			readnotnull ? tmp_evts[DIR_RD] : NULL,
+			writenotnull ? tmp_evts[DIR_WR] : NULL,
+			NULL,
+			&delta);
+	clock_update_date(delta_ms, status);
+	fd_leaving_poll(delta_ms, status);
+
+	if (status <= 0)
+		return;
+
+	activity[tid].poll_io++;
+
+	for (fds = 0; (fds * BITS_PER_INT) < maxfd; fds++) {
+		if ((((int *)(tmp_evts[DIR_RD]))[fds] | ((int *)(tmp_evts[DIR_WR]))[fds]) == 0)
+			continue;
+
+		for (count = BITS_PER_INT, fd = fds * BITS_PER_INT; count && fd < maxfd; count--, fd++) {
+			unsigned int n = 0;
+
+			if (FD_ISSET(fd, tmp_evts[DIR_RD]))
+				n |= FD_EV_READY_R;
+
+			if (FD_ISSET(fd, tmp_evts[DIR_WR]))
+				n |= FD_EV_READY_W;
+
+			if (!n)
+				continue;
+
+#ifdef DEBUG_FD
+			_HA_ATOMIC_INC(&fdtab[fd].event_count);
+#endif
+
+			fd_update_events(fd, n);
+		}
+	}
+}
+
+static int init_select_per_thread()
+{
+	int fd_set_bytes;
+
+	fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
+	tmp_evts[DIR_RD] = calloc(1, fd_set_bytes);
+	if (tmp_evts[DIR_RD] == NULL)
+		goto fail;
+	tmp_evts[DIR_WR] = calloc(1, fd_set_bytes);
+	if (tmp_evts[DIR_WR] == NULL)
+		goto fail;
+	return 1;
+  fail:
+	free(tmp_evts[DIR_RD]);
+	free(tmp_evts[DIR_WR]);
+	return 0;
+}
+
+static void deinit_select_per_thread()
+{
+	ha_free(&tmp_evts[DIR_WR]);
+	ha_free(&tmp_evts[DIR_RD]);
+}
+
+/*
+ * Initialization of the select() poller.
+ * Returns 0 in case of failure, non-zero in case of success. If it fails, it
+ * disables the poller by setting its pref to 0.
+ */
+static int _do_init(struct poller *p)
+{
+	int fd_set_bytes;
+
+	p->private = NULL;
+
+	/* this old poller uses a process-wide FD list that cannot work with
+	 * groups.
+	 */
+	if (global.nbtgroups > 1)
+		goto fail_srevt;
+
+	if (global.maxsock > FD_SETSIZE)
+		goto fail_srevt;
+
+	fd_set_bytes = sizeof(fd_set) * (global.maxsock + FD_SETSIZE - 1) / FD_SETSIZE;
+
+	if ((fd_evts[DIR_RD] = calloc(1, fd_set_bytes)) == NULL)
+		goto fail_srevt;
+	if ((fd_evts[DIR_WR] = calloc(1, fd_set_bytes)) == NULL)
+		goto fail_swevt;
+
+	hap_register_per_thread_init(init_select_per_thread);
+	hap_register_per_thread_deinit(deinit_select_per_thread);
+
+	return 1;
+
+ fail_swevt:
+	free(fd_evts[DIR_RD]);
+ fail_srevt:
+	p->pref = 0;
+	return 0;
+}
+
+/*
+ * Termination of the select() poller.
+ * Memory is released and the poller is marked as unselectable.
+ */
+static void _do_term(struct poller *p)
+{
+	free(fd_evts[DIR_WR]);
+	free(fd_evts[DIR_RD]);
+	p->private = NULL;
+	p->pref = 0;
+}
+
+/*
+ * Check that the poller works.
+ * Returns 1 if OK, otherwise 0.
+ */
+static int _do_test(struct poller *p)
+{
+	if (global.maxsock > FD_SETSIZE)
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Registers the poller.
+ */
+static void _do_register(void)
+{
+	struct poller *p;
+
+	if (nbpollers >= MAX_POLLERS)
+		return;
+	p = &pollers[nbpollers++];
+
+	p->name = "select";
+	p->pref = 150;
+	p->flags = 0;
+	p->private = NULL;
+
+	p->clo  = __fd_clo;
+	p->test = _do_test;
+	p->init = _do_init;
+	p->term = _do_term;
+	p->poll = _do_poll;
+}
+
+INITCALL0(STG_REGISTER, _do_register);
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */