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authorBrad Spencer <bspencer@blackberry.com>2018-12-14 17:18:22 -0400
committerDaniel Stenberg <daniel@haxx.se>2019-01-07 10:05:20 +0100
commit84a30d0a419ad95c53cbdfc76eb2eb75d2e51835 (patch)
tree5a7c04df819a465e7711f9c9b0c831f5532b0326 /tests/libtest/lib1592.c
parentebe658c1e5a6577178981a7f406794699305be5c (diff)
curl_multi_remove_handle() don't block terminating c-ares requests
Added Curl_resolver_kill() for all three resolver modes, which only blocks when necessary, along with test 1592 to confirm curl_multi_remove_handle() doesn't block unless it must. Closes #3428 Fixes #3371
Diffstat (limited to 'tests/libtest/lib1592.c')
-rw-r--r--tests/libtest/lib1592.c119
1 files changed, 119 insertions, 0 deletions
diff --git a/tests/libtest/lib1592.c b/tests/libtest/lib1592.c
new file mode 100644
index 000000000..5e6bf04eb
--- /dev/null
+++ b/tests/libtest/lib1592.c
@@ -0,0 +1,119 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+/*
+ * See https://github.com/curl/curl/issues/3371
+ *
+ * This test case checks whether curl_multi_remove_handle() cancels
+ * asynchronous DNS resolvers without blocking where possible. Obviously, it
+ * only tests whichever resolver cURL is actually built with.
+ */
+
+/* We're willing to wait a very generous two seconds for the removal. This is
+ as low as we can go while still easily supporting SIGALRM timing for the
+ non-threaded blocking resolver. It doesn't matter that much because when
+ the test passes, we never wait this long. */
+#define TEST_HANG_TIMEOUT 2 * 1000
+
+#include "test.h"
+#include "testutil.h"
+
+#include <sys/stat.h>
+
+int test(char *URL)
+{
+ int stillRunning;
+ CURLM *multiHandle = NULL;
+ CURL *curl = NULL;
+ CURLMcode res = CURLM_OK;
+ int timeout;
+
+ global_init(CURL_GLOBAL_ALL);
+
+ multi_init(multiHandle);
+
+ easy_init(curl);
+
+ easy_setopt(curl, CURLOPT_VERBOSE, 1L);
+ easy_setopt(curl, CURLOPT_URL, URL);
+
+ /* Set a DNS server that hopefully will not respond when using c-ares. */
+ if(curl_easy_setopt(curl, CURLOPT_DNS_SERVERS, "0.0.0.0") == CURLE_OK)
+ /* Since we could set the DNS server, presume we are working with a
+ resolver that can be cancelled (i.e. c-ares). Thus,
+ curl_multi_remove_handle() should not block even when the resolver
+ request is outstanding. So, set a request timeout _longer_ than the
+ test hang timeout so we will fail if the handle removal call incorrectly
+ blocks. */
+ timeout = TEST_HANG_TIMEOUT * 2;
+ else {
+ /* If we can't set the DNS server, presume that we are configured to use a
+ resolver that can't be cancelled (i.e. the threaded resolver or the
+ non-threaded blocking resolver). So, we just test that the
+ curl_multi_remove_handle() call does finish well within our test
+ timeout.
+
+ But, it is very unlikely that the resolver request will take any time at
+ all because we haven't been able to configure the resolver to use an
+ non-responsive DNS server. At least we exercise the flow.
+ */
+ fprintf(stderr,
+ "CURLOPT_DNS_SERVERS not supported; "
+ "assuming curl_multi_remove_handle() will block\n");
+ timeout = TEST_HANG_TIMEOUT / 2;
+ }
+
+ /* Setting a timeout on the request should ensure that even if we have to
+ wait for the resolver during curl_multi_remove_handle(), it won't take
+ longer than this, because the resolver request inherits its timeout from
+ this. */
+ easy_setopt(curl, CURLOPT_TIMEOUT_MS, timeout);
+
+ multi_add_handle(multiHandle, curl);
+
+ /* This should move the handle from INIT => CONNECT => WAITRESOLVE. */
+ fprintf(stderr, "curl_multi_perform()...\n");
+ multi_perform(multiHandle, &stillRunning);
+ fprintf(stderr, "curl_multi_perform() succeeded\n");
+
+ /* Start measuring how long it takes to remove the handle. */
+ fprintf(stderr, "curl_multi_remove_handle()...\n");
+ start_test_timing();
+ res = curl_multi_remove_handle(multiHandle, curl);
+ if(res) {
+ fprintf(stderr, "curl_multi_remove_handle() failed, "
+ "with code %d\n", (int)res);
+ goto test_cleanup;
+ }
+ fprintf(stderr, "curl_multi_remove_handle() succeeded\n");
+
+ /* Fail the test if it took too long to remove. This happens after the fact,
+ and says "it seems that it would have run forever", which isn't true, but
+ it's close enough, and simple to do. */
+ abort_on_test_timeout();
+
+test_cleanup:
+ curl_easy_cleanup(curl);
+ curl_multi_cleanup(multiHandle);
+ curl_global_cleanup();
+
+ return (int)res;
+}