Add a unit test for event_base_dump_events()

This function uses a C program to generate its output, and then uses a
Python program to check it for correctness.  On systems without
Python, we just make sure that the C program doesn't crash.

It's likely that we should be requiring some particular python version.
This is an alpha, though: I'm sure somebody will tell us which.

.gitignore

@@ -88,6 +88,7 @@ libevent_openssl.pc
 /test/regress.gen.c
 /test/regress.gen.h
 /test/rpcgen-attempted
+/test/test-dumpevents
 /test/test-eof
 /test/test-init
 /test/test-ratelim

test/Makefile.am

@@ -10,7 +10,7 @@ AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/compat -I$(top_srcdir)/include -I.
 
 EXTRA_DIST = regress.rpc regress.gen.h regress.gen.c rpcgen_wrapper.sh test.sh
 
-noinst_PROGRAMS = test-init test-eof test-weof test-time \
+noinst_PROGRAMS = test-init test-eof test-weof test-time test-dumpevents \
 	bench bench_cascade bench_http bench_httpclient test-ratelim \
 	test-changelist test-fdleak
 if BUILD_REGRESS
@@ -28,6 +28,8 @@ endif
 
 test_init_SOURCES = test-init.c
 test_init_LDADD = ../libevent_core.la
+test_dumpevents_SOURCES = test-dumpevents.c
+test_dumpevents_LDADD = ../libevent_core.la
 test_eof_SOURCES = test-eof.c
 test_eof_LDADD = ../libevent_core.la
 test_changelist_SOURCES = test-changelist.c

test/check-dumpevents.py

@@ -0,0 +1,54 @@
+#!/usr/bin/python
+#
+# Post-process the output of test-dumpevents and check it for correctness.
+#
+
+import math
+import re
+import sys
+
+text = sys.stdin.readlines()
+
+try:
+    expect_inserted_pos = text.index("Inserted:\n")
+    expect_active_pos = text.index("Active:\n")
+    got_inserted_pos = text.index("Inserted events:\n")
+    got_active_pos = text.index("Active events:\n")
+except ValueError:
+    print >>sys.stderr, "Missing expected dividing line in dumpevents output"
+    sys.exit(1)
+
+if not (expect_inserted_pos < expect_active_pos <
+        got_inserted_pos < got_active_pos):
+    print >>sys.stderr, "Sections out of order in dumpevents output"
+    sys.exit(1)
+
+now,T= text[1].split()
+T = float(T)
+
+want_inserted = set(text[expect_inserted_pos+1:expect_active_pos])
+want_active = set(text[expect_active_pos+1:got_inserted_pos-1])
+got_inserted = set(text[got_inserted_pos+1:got_active_pos])
+got_active = set(text[got_active_pos+1:])
+
+pat = re.compile(r'Timeout=([0-9\.]+)')
+def replace_time(m):
+    t = float(m.group(1))
+    if .9 < abs(t-T) < 1.1:
+        return "Timeout=T+1"
+    elif 2.4 < abs(t-T) < 2.6:
+        return "Timeout=T+2.5"
+    else:
+        return m.group(0)
+
+cleaned_inserted = set( pat.sub(replace_time, s) for s in got_inserted
+                        if "Internal" not in s)
+
+if cleaned_inserted != want_inserted:
+    print >>sys.stderr, "Inserted event lists were not as expected!"
+    sys.exit(1)
+
+if set(got_active) != set(want_active):
+    print >>sys.stderr, "Active event lists were not as expected!"
+    sys.exit(1)
+

test/test-dumpevents.c

@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 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 "event2/event-config.h"
+
+#ifdef _WIN32
+#include <winsock2.h>
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#include <event2/event.h>
+#include "util-internal.h"
+
+static void
+sock_perror(const char *s)
+{
+#ifdef _WIN32
+	const char *err = evutil_socket_error_to_string(EVUTIL_SOCKET_ERROR());
+	fprintf(stderr, "%s: %s\n", s, err);
+#else
+	perror(s);
+#endif
+}
+
+static void
+callback1(evutil_socket_t fd, short events, void *arg)
+{
+}
+static void
+callback2(evutil_socket_t fd, short events, void *arg)
+{
+}
+
+/* Testing code for event_base_dump_events().
+
+   Notes that just because we have code to exercise this function,
+   doesn't mean that *ANYTHING* about the output format is guaranteed to
+   remain in the future.
+ */
+int
+main(int argc, char **argv)
+{
+#define N_EVENTS 13
+	int i;
+	struct event *ev[N_EVENTS];
+	evutil_socket_t pair1[2];
+	evutil_socket_t pair2[2];
+	struct timeval tv_onesec = {1,0};
+	struct timeval tv_two5sec = {2,500*1000};
+	const struct timeval *tv_onesec_common;
+	const struct timeval *tv_two5sec_common;
+	struct event_base *base;
+	struct timeval now;
+
+#ifdef _WIN32
+	WORD wVersionRequested;
+	WSADATA wsaData;
+	int	err;
+
+	wVersionRequested = MAKEWORD(2, 2);
+
+	err = WSAStartup(wVersionRequested, &wsaData);
+#endif
+
+#ifdef _WIN32
+#define LOCAL_SOCKETPAIR_AF AF_INET
+#else
+#define LOCAL_SOCKETPAIR_AF AF_UNIX
+#endif
+
+	if (evutil_make_internal_pipe_(pair1) < 0 ||
+	    evutil_make_internal_pipe_(pair2) < 0) {
+		sock_perror("evutil_make_internal_pipe_");
+		return 1;
+	}
+
+	if (!(base = event_base_new())) {
+		fprintf(stderr,"Couldn't make event_base\n");
+		return 2;
+	}
+
+	tv_onesec_common = event_base_init_common_timeout(base, &tv_onesec);
+	tv_two5sec_common = event_base_init_common_timeout(base, &tv_two5sec);
+
+	ev[0] = event_new(base, pair1[0], EV_WRITE, callback1, NULL);
+	ev[1] = event_new(base, pair1[1], EV_READ|EV_PERSIST, callback1, NULL);
+	ev[2] = event_new(base, pair2[0], EV_WRITE|EV_PERSIST, callback2, NULL);
+	ev[3] = event_new(base, pair2[1], EV_READ, callback2, NULL);
+
+	/* For timers */
+	ev[4] = evtimer_new(base, callback1, NULL);
+	ev[5] = evtimer_new(base, callback1, NULL);
+	ev[6] = evtimer_new(base, callback1, NULL);
+	ev[7] = event_new(base, -1, EV_PERSIST, callback2, NULL);
+	ev[8] = event_new(base, -1, EV_PERSIST, callback2, NULL);
+	ev[9] = event_new(base, -1, EV_PERSIST, callback2, NULL);
+
+	/* To activate */
+	ev[10] = event_new(base, -1, 0, callback1, NULL);
+	ev[11] = event_new(base, -1, 0, callback2, NULL);
+
+	/* Signals */
+	ev[12] = evsignal_new(base, SIGINT, callback2, NULL);
+
+	event_add(ev[0], NULL);
+	event_add(ev[1], &tv_onesec);
+	event_add(ev[2], tv_onesec_common);
+	event_add(ev[3], tv_two5sec_common);
+
+	event_add(ev[4], tv_onesec_common);
+	event_add(ev[5], tv_onesec_common);
+	event_add(ev[6], &tv_onesec);
+	event_add(ev[7], tv_two5sec_common);
+	event_add(ev[8], tv_onesec_common);
+	event_add(ev[9], &tv_two5sec);
+
+	event_active(ev[10], EV_READ, 1);
+	event_active(ev[11], EV_READ|EV_WRITE|EV_TIMEOUT, 1);
+	event_active(ev[1], EV_READ, 1);
+
+	event_add(ev[12], NULL);
+
+	evutil_gettimeofday(&now,NULL);
+	puts("=====expected");
+	printf("Now= %ld.%06d\n",(long)now.tv_sec,(int)now.tv_usec);
+	puts("Inserted:");
+	printf("  %p [fd  %ld] Write\n",ev[0],(long)pair1[0]);
+	printf("  %p [fd  %ld] Read Persist Timeout=T+1\n",ev[1],(long)pair1[1]);
+	printf("  %p [fd  %ld] Write Persist Timeout=T+1\n",ev[2],(long)pair2[0]);
+	printf("  %p [fd  %ld] Read Timeout=T+2.5\n",ev[3],(long)pair2[1]);
+	printf("  %p [fd  -1] Timeout=T+1\n",ev[4]);
+	printf("  %p [fd  -1] Timeout=T+1\n",ev[5]);
+	printf("  %p [fd  -1] Timeout=T+1\n",ev[6]);
+	printf("  %p [fd  -1] Persist Timeout=T+2.5\n",ev[7]);
+	printf("  %p [fd  -1] Persist Timeout=T+1\n",ev[8]);
+	printf("  %p [fd  -1] Persist Timeout=T+2.5\n",ev[9]);
+	printf("  %p [sig %d] Signal Persist\n", ev[12], (int)SIGINT);
+
+	puts("Active:");
+	printf("  %p [fd  -1, priority=0] Read active\n", ev[10]);
+	printf("  %p [fd  -1, priority=0] Read Write Timeout active\n", ev[11]);
+	printf("  %p [fd  %ld, priority=0] Read active\n", ev[1], (long)pair1[1]);
+
+	puts("======received");
+	event_base_dump_events(base, stdout);
+
+	for (i = 0; i < N_EVENTS; ++i) {
+		event_free(ev[i]);
+	}
+	event_base_free(base);
+
+	return 0;
+}
+

test/test.sh

@@ -105,6 +105,22 @@ run_tests () {
 		announce FAILED ;
 		FAILED=yes
 	fi
+	announce_n " test-dumpevents: "
+	if test "`which python 2>/dev/null`" != ""; then
+	    if $TEST_DIR/test-dumpevents | python $TEST_DIR/check-dumpevents.py >> "$TEST_OUTPUT_FILE" ;
+	    then
+	        announce OKAY ;
+	    else
+	        announce FAILED ;
+	    fi
+	else
+	    # no python
+	    if $TEST_DIR/test-dumpevents >/dev/null; then
+	        announce "OKAY (output not checked)" ;
+	    else
+	        announce "FAILED (output not checked)" ;
+	    fi
+	fi
 	test -x $TEST_DIR/regress || return
 	announce_n " regress: "
 	if test "$TEST_OUTPUT_FILE" = "/dev/null" ;