Add tests for cross-thread user events, and for closing kqueues resulting in waits being cancelled

Author: arr2036

test/CMakeLists.txt

@@ -13,6 +13,8 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #
+cmake_minimum_required(VERSION 3.7.2)
+
 project(libkqueue-test LANGUAGES C)
 
 set(LIBKQUEUE_TEST_SOURCES
@@ -23,6 +25,7 @@ set(LIBKQUEUE_TEST_SOURCES
     proc.c
     read.c
     test.c
+    threading.c
     timer.c
     user.c
     vnode.c

test/common.h

@@ -119,6 +119,7 @@ void test_evfilt_proc(struct test_context *);
 void test_evfilt_user(struct test_context *);
 #endif
 void test_evfilt_libkqueue(struct test_context *);
+void test_threading(struct test_context *);
 
 #define test(f, ctx ,...) do {                                            \
     if ((ctx->test->ut_num >= ctx->test->ut_start) && (ctx->test->ut_num <= ctx->test->ut_end)) {\

test/main.c

@@ -186,6 +186,10 @@ main(int argc, char **argv)
           .ut_end = INT_MAX },
         { NULL, 0, NULL },
 #endif
+        { .ut_name = "threading",
+          .ut_enabled = 1,
+          .ut_func = test_threading,
+          .ut_end = INT_MAX },
     };
     struct unit_test *test;
     int c, i, iterations;

test/threading.c

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2025 Arran Cudbard-Bell <a.cudbardb@freeradius.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "common.h"
+
+struct trigger_args {
+    int         kqfd;
+    uintptr_t   ident;
+};
+
+static void *
+close_kqueue(void *arg)
+{
+	/* Sleep until we're fairly sure the other thread is waiting */
+	sleep(1);
+
+    /* Close the waiting kqueue from this thread */
+    if (close(*((int *)arg)) != 0)
+		die("close failed");
+
+    return NULL;
+}
+
+static void
+test_kevent_threading_close(struct test_context *ctx)
+{
+    struct kevent kev, ret[1];
+    pthread_t th;
+	int kqfd = kqueue();
+
+    /* Add the event, then trigger it from another thread */
+    kevent_add(kqfd, &kev, 1, EVFILT_USER, EV_ADD | EV_CLEAR, 0, 0, NULL);
+
+    if (pthread_create(&th, NULL, close_kqueue, &kqfd) != 0)
+        die("failed creating thread");
+
+	/* Wait for event (should be interrupted by close) */
+	if (kevent(kqfd, NULL, 0, ret, 1, NULL) == -1) {
+		if (errno != EBADF)
+			die("kevent failed with the wrong errno");
+	} else {
+		die("kevent did not fail");
+	}
+
+	/* Subsequent calls should also fail with EBADF */
+	if (kevent(kqfd, NULL, 0, ret, 1, NULL) == -1) {
+		if (errno != EBADF)
+			die("kevent failed with the wrong errno (second call)");
+	} else {
+		die("kevent did not fail (second call)");
+	}
+
+    if (pthread_join(th, NULL) != 0)
+        die("pthread_join failed");
+}
+
+void
+test_threading(struct test_context *ctx)
+{
+	test(kevent_threading_close, ctx);
+}

test/user.c

@@ -176,6 +176,55 @@ test_kevent_user_dispatch(struct test_context *ctx)
 }
 #endif     /* EV_DISPATCH */
 
+struct trigger_args {
+    int         kqfd;
+    uintptr_t   ident;
+};
+
+static void *
+trigger_user_event_thread(void *arg)
+{
+    struct trigger_args *ta = arg;
+    struct kevent tmp;
+
+    /* Trigger the user event from this thread */
+    kevent_add(ta->kqfd, &tmp, ta->ident, EVFILT_USER, 0, NOTE_TRIGGER, 0, NULL);
+    return NULL;
+}
+
+static void
+test_kevent_user_trigger_from_thread(struct test_context *ctx)
+{
+    struct kevent kev, ret[1];
+    pthread_t th;
+    struct trigger_args args;
+
+    test_no_kevents(ctx->kqfd);
+
+    /* Use a distinct ident to avoid confusion with other tests */
+    args.kqfd = ctx->kqfd;
+    args.ident = 3;
+
+    /* Add the event, then trigger it from another thread */
+    kevent_add(ctx->kqfd, &kev, args.ident, EVFILT_USER, EV_ADD | EV_CLEAR, 0, 0, NULL);
+
+    if (pthread_create(&th, NULL, trigger_user_event_thread, &args) != 0)
+        die("failed creating thread");
+
+    if (pthread_join(th, NULL) != 0)
+        die("pthread_join failed");
+
+    /* Prepare expected event (mask out control bits) */
+    kev.fflags &= ~NOTE_FFCTRLMASK;
+    kev.fflags &= ~NOTE_TRIGGER;
+
+    /* Fetch and compare */
+    kevent_get(ret, NUM_ELEMENTS(ret), ctx->kqfd, 1);
+    kevent_cmp(&kev, ret);
+
+    test_no_kevents(ctx->kqfd);
+}
+
 void
 test_evfilt_user(struct test_context *ctx)
 {
@@ -188,5 +237,6 @@ test_evfilt_user(struct test_context *ctx)
 #ifdef EV_DISPATCH
     test(kevent_user_dispatch, ctx);
 #endif
+    test(kevent_user_trigger_from_thread, ctx);
     /* TODO: try different fflags operations */
 }