Revert "Revert "Upgrade to 2.1.8-stable (2017-01-22)." and "Probably Mac build fix?""

This reverts commit 83a0c9c65a60a92d3ea5542596b3ba56db492c37.

Bug: 64543673
Test: make checkbuild
Test: Manual tombstoned test
Change-Id: I84bb128d1dec433195f2cbdbf70236ba17fa9955
diff --git a/test/regress_et.c b/test/regress_et.c
new file mode 100644
index 0000000..f75c59b
--- /dev/null
+++ b/test/regress_et.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "../util-internal.h"
+#include "event2/event-config.h"
+
+#ifdef _WIN32
+#include <winsock2.h>
+#endif
+#include <sys/types.h>
+#include <sys/stat.h>
+#ifdef EVENT__HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#ifndef _WIN32
+#include <sys/time.h>
+#include <unistd.h>
+#endif
+#include <errno.h>
+
+#include "event2/event.h"
+#include "event2/util.h"
+
+#include "regress.h"
+
+static int was_et = 0;
+
+static void
+read_cb(evutil_socket_t fd, short event, void *arg)
+{
+	char buf;
+	int len;
+
+	len = recv(fd, &buf, sizeof(buf), 0);
+
+	called++;
+	if (event & EV_ET)
+		was_et = 1;
+
+	if (!len)
+		event_del(arg);
+}
+
+#ifdef _WIN32
+#define LOCAL_SOCKETPAIR_AF AF_INET
+#else
+#define LOCAL_SOCKETPAIR_AF AF_UNIX
+#endif
+
+static void
+test_edgetriggered(void *et)
+{
+	struct event *ev = NULL;
+	struct event_base *base = NULL;
+	const char *test = "test string";
+	evutil_socket_t pair[2] = {-1,-1};
+	int supports_et;
+
+	/* On Linux 3.2.1 (at least, as patched by Fedora and tested by Nick),
+	 * doing a "recv" on an AF_UNIX socket resets the readability of the
+	 * socket, even though there is no state change, so we don't actually
+	 * get edge-triggered behavior.  Yuck!  Linux 3.1.9 didn't have this
+	 * problem.
+	 */
+#ifdef __linux__
+	if (evutil_ersatz_socketpair_(AF_INET, SOCK_STREAM, 0, pair) == -1) {
+		tt_abort_perror("socketpair");
+	}
+#else
+	if (evutil_socketpair(LOCAL_SOCKETPAIR_AF, SOCK_STREAM, 0, pair) == -1) {
+		tt_abort_perror("socketpair");
+	}
+#endif
+
+	called = was_et = 0;
+
+	tt_int_op(send(pair[0], test, (int)strlen(test)+1, 0), >, 0);
+	shutdown(pair[0], EVUTIL_SHUT_WR);
+
+	/* Initalize the event library */
+	base = event_base_new();
+
+	if (!strcmp(event_base_get_method(base), "epoll") ||
+	    !strcmp(event_base_get_method(base), "epoll (with changelist)") ||
+	    !strcmp(event_base_get_method(base), "kqueue"))
+		supports_et = 1;
+	else
+		supports_et = 0;
+
+	TT_BLATHER(("Checking for edge-triggered events with %s, which should %s"
+				"support edge-triggering", event_base_get_method(base),
+				supports_et?"":"not "));
+
+	/* Initalize one event */
+	ev = event_new(base, pair[1], EV_READ|EV_ET|EV_PERSIST, read_cb, &ev);
+
+	event_add(ev, NULL);
+
+	/* We're going to call the dispatch function twice.  The first invocation
+	 * will read a single byte from pair[1] in either case.  If we're edge
+	 * triggered, we'll only see the event once (since we only see transitions
+	 * from no data to data), so the second invocation of event_base_loop will
+	 * do nothing.  If we're level triggered, the second invocation of
+	 * event_base_loop will also activate the event (because there's still
+	 * data to read). */
+	event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE);
+	event_base_loop(base,EVLOOP_NONBLOCK|EVLOOP_ONCE);
+
+	if (supports_et) {
+		tt_int_op(called, ==, 1);
+		tt_assert(was_et);
+	} else {
+		tt_int_op(called, ==, 2);
+		tt_assert(!was_et);
+	}
+
+ end:
+	if (ev) {
+		event_del(ev);
+		event_free(ev);
+	}
+	if (base)
+		event_base_free(base);
+	evutil_closesocket(pair[0]);
+	evutil_closesocket(pair[1]);
+}
+
+static void
+test_edgetriggered_mix_error(void *data_)
+{
+	struct basic_test_data *data = data_;
+	struct event_base *base = NULL;
+	struct event *ev_et=NULL, *ev_lt=NULL;
+
+#ifdef EVENT__DISABLE_DEBUG_MODE
+	if (1)
+		tt_skip();
+#endif
+
+	if (!libevent_tests_running_in_debug_mode)
+		event_enable_debug_mode();
+
+	base = event_base_new();
+
+	/* try mixing edge-triggered and level-triggered to make sure it fails*/
+	ev_et = event_new(base, data->pair[0], EV_READ|EV_ET, read_cb, ev_et);
+	tt_assert(ev_et);
+	ev_lt = event_new(base, data->pair[0], EV_READ, read_cb, ev_lt);
+	tt_assert(ev_lt);
+
+	/* Add edge-triggered, then level-triggered.  Get an error. */
+	tt_int_op(0, ==, event_add(ev_et, NULL));
+	tt_int_op(-1, ==, event_add(ev_lt, NULL));
+	tt_int_op(EV_READ, ==, event_pending(ev_et, EV_READ, NULL));
+	tt_int_op(0, ==, event_pending(ev_lt, EV_READ, NULL));
+
+	tt_int_op(0, ==, event_del(ev_et));
+	/* Add level-triggered, then edge-triggered.  Get an error. */
+	tt_int_op(0, ==, event_add(ev_lt, NULL));
+	tt_int_op(-1, ==, event_add(ev_et, NULL));
+	tt_int_op(EV_READ, ==, event_pending(ev_lt, EV_READ, NULL));
+	tt_int_op(0, ==, event_pending(ev_et, EV_READ, NULL));
+
+end:
+	if (ev_et)
+		event_free(ev_et);
+	if (ev_lt)
+		event_free(ev_lt);
+	if (base)
+		event_base_free(base);
+}
+
+struct testcase_t edgetriggered_testcases[] = {
+	{ "et", test_edgetriggered, TT_FORK, NULL, NULL },
+	{ "et_mix_error", test_edgetriggered_mix_error,
+	  TT_FORK|TT_NEED_SOCKETPAIR|TT_NO_LOGS, &basic_setup, NULL },
+	END_OF_TESTCASES
+};