test: add framework for simulating multithreading in unit tests

Use the mock wrappers to override pthread_self(), enabling the
unit tests to switch emulation between different threads
from the context of a single unit test thread.

Add this into the io_channel unit tests with some very basic
testing of allocating and freeing multiple threads.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I8742f16c39e92e82065dc5b8f2e5b2e79273a4f8

Reviewed-on: https://review.gerrithub.io/377992
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>

test/lib/ut_multithread.c

@@ -0,0 +1,169 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "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 COPYRIGHT
+ *   OWNER OR CONTRIBUTORS 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 "spdk_cunit.h"
+#include "spdk/io_channel.h"
+#include "spdk_internal/mock.h"
+
+static uint32_t g_ut_num_threads;
+
+int allocate_threads(int num_threads);
+void free_threads(void);
+void poll_threads(void);
+int poll_thread(uintptr_t thread_id);
+
+struct ut_msg {
+	spdk_thread_fn		fn;
+	void			*ctx;
+	TAILQ_ENTRY(ut_msg)	link;
+};
+
+struct ut_thread {
+	struct spdk_thread	*thread;
+	struct spdk_io_channel	*ch;
+	TAILQ_HEAD(, ut_msg)	msgs;
+};
+
+struct ut_thread *g_ut_threads;
+
+static void
+__send_msg(spdk_thread_fn fn, void *ctx, void *thread_ctx)
+{
+	struct ut_thread *thread = thread_ctx;
+	struct ut_msg *msg;
+
+	msg = calloc(1, sizeof(*msg));
+	SPDK_CU_ASSERT_FATAL(msg != NULL);
+
+	msg->fn = fn;
+	msg->ctx = ctx;
+	TAILQ_INSERT_TAIL(&thread->msgs, msg, link);
+}
+
+static uintptr_t g_thread_id = MOCK_PASS_THRU;
+
+static void
+set_thread(uintptr_t thread_id)
+{
+	g_thread_id = thread_id;
+	MOCK_SET(pthread_self, pthread_t, (pthread_t)thread_id);
+}
+
+int
+allocate_threads(int num_threads)
+{
+	struct spdk_thread *thread;
+	uint32_t i;
+
+	g_ut_num_threads = num_threads;
+
+	g_ut_threads = calloc(num_threads, sizeof(*g_ut_threads));
+	SPDK_CU_ASSERT_FATAL(g_ut_threads != NULL);
+
+	for (i = 0; i < g_ut_num_threads; i++) {
+		set_thread(i);
+		spdk_allocate_thread(__send_msg, &g_ut_threads[i], NULL);
+		thread = spdk_get_thread();
+		SPDK_CU_ASSERT_FATAL(thread != NULL);
+		g_ut_threads[i].thread = thread;
+		TAILQ_INIT(&g_ut_threads[i].msgs);
+	}
+
+	set_thread(MOCK_PASS_THRU);
+	return 0;
+}
+
+void
+free_threads(void)
+{
+	uint32_t i;
+
+	for (i = 0; i < g_ut_num_threads; i++) {
+		set_thread(i);
+		spdk_free_thread();
+	}
+
+	g_ut_num_threads = 0;
+	free(g_ut_threads);
+	g_ut_threads = NULL;
+}
+
+int
+poll_thread(uintptr_t thread_id)
+{
+	int count = 0;
+	struct ut_thread *thread = &g_ut_threads[thread_id];
+	struct ut_msg *msg;
+	uintptr_t original_thread_id;
+
+	CU_ASSERT(thread_id != (uintptr_t)MOCK_PASS_THRU);
+	CU_ASSERT(thread_id < g_ut_num_threads);
+
+	original_thread_id = g_thread_id;
+	set_thread(thread_id);
+
+	while (!TAILQ_EMPTY(&thread->msgs)) {
+		msg = TAILQ_FIRST(&thread->msgs);
+		TAILQ_REMOVE(&thread->msgs, msg, link);
+
+		msg->fn(msg->ctx);
+		count++;
+		free(msg);
+	}
+
+	set_thread(original_thread_id);
+
+	return count;
+}
+
+void
+poll_threads(void)
+{
+	bool msg_processed;
+	uint32_t i, count;
+
+	while (true) {
+		msg_processed = false;
+
+		for (i = 0; i < g_ut_num_threads; i++) {
+			count = poll_thread(i);
+			if (count > 0) {
+				msg_processed = true;
+			}
+		}
+
+		if (!msg_processed) {
+			break;
+		}
+	}
+}

test/unit/lib/util/io_channel.c/Makefile

@@ -34,8 +34,9 @@
 SPDK_ROOT_DIR := $(abspath $(CURDIR)/../../../../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 include $(SPDK_ROOT_DIR)/mk/spdk.app.mk
+include $(SPDK_ROOT_DIR)/mk/spdk.mock.unittest.mk
 
-SPDK_LIB_LIST = log cunit
+SPDK_LIB_LIST = log cunit spdk_mock
 
 CFLAGS += $(ENV_CFLAGS)
 CFLAGS += -I$(SPDK_ROOT_DIR)/test

test/unit/lib/util/io_channel.c/io_channel_ut.c

@@ -36,6 +36,8 @@
 #include "spdk_cunit.h"
 
 #include "util/io_channel.c"
+#include "lib/test_env.c"
+#include "lib/ut_multithread.c"
 
 static void
 _send_msg(spdk_thread_fn fn, void *ctx, void *thread_ctx)
@@ -45,6 +47,58 @@ _send_msg(spdk_thread_fn fn, void *ctx, void *thread_ctx)
 
 static void
 thread_alloc(void)
+{
+	CU_ASSERT(TAILQ_EMPTY(&g_threads));
+	allocate_threads(1);
+	CU_ASSERT(!TAILQ_EMPTY(&g_threads));
+	free_threads();
+	CU_ASSERT(TAILQ_EMPTY(&g_threads));
+}
+
+static void
+send_msg_cb(void *ctx)
+{
+	bool *done = ctx;
+
+	*done = true;
+}
+
+static void
+thread_send_msg(void)
+{
+	struct spdk_thread *thread0;
+	bool done = false;
+
+	allocate_threads(2);
+	set_thread(0);
+	thread0 = spdk_get_thread();
+
+	set_thread(1);
+	/* Simulate thread 1 sending a message to thread 0. */
+	spdk_thread_send_msg(thread0, send_msg_cb, &done);
+
+	/* We have not polled thread 0 yet, so done should be false. */
+	CU_ASSERT(!done);
+
+	/*
+	 * Poll thread 1.  The message was sent to thread 0, so this should be
+	 *  a nop and done should still be false.
+	 */
+	poll_thread(1);
+	CU_ASSERT(!done);
+
+	/*
+	 * Poll thread 0.  This should execute the message and done should then
+	 *  be true.
+	 */
+	poll_thread(0);
+	CU_ASSERT(done);
+
+	free_threads();
+}
+
+static void
+thread_name(void)
 {
 	struct spdk_thread *thread;
 	const char *name;
@@ -189,6 +243,8 @@ main(int argc, char **argv)
 
 	if (
 		CU_add_test(suite, "thread_alloc", thread_alloc) == NULL ||
+		CU_add_test(suite, "thread_send_msg", thread_send_msg) == NULL ||
+		CU_add_test(suite, "thread_name", thread_name) == NULL ||
 		CU_add_test(suite, "channel", channel) == NULL
 	) {
 		CU_cleanup_registry();