[PATCH net-next v3 4/6] selftests: net: add multithread client support to iou-zcrx

[Juanlu Herrero <juanlu@fastmail.com>]

Add pthreads to the iou-zcrx client so that multiple connections can be
established simultaneously. Each client thread connects to the server
and sends its payload independently.

Introduce the -t option to control the number of threads (default 1),
preserving backwards compatibility with existing tests.

Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Juanlu Herrero <juanlu@fastmail.com>
---
 .../testing/selftests/drivers/net/hw/Makefile |  2 +-
 .../selftests/drivers/net/hw/iou-zcrx.c       | 38 +++++++++++++++++--
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 234db5c2c90cc..3cab3b4adbb2e 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -88,5 +88,5 @@ include ../../../net/ynl.mk
 include ../../../net/bpf.mk
 
 ifeq ($(HAS_IOURING_ZCRX),y)
-$(OUTPUT)/iou-zcrx: LDLIBS += -luring
+$(OUTPUT)/iou-zcrx: LDLIBS += -luring -lpthread
 endif
diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index 9b62fd0703e61..7bc61f3b70ca6 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -4,6 +4,7 @@
 #include <error.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <pthread.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -85,9 +86,12 @@ static int cfg_send_size = SEND_SIZE;
 static struct sockaddr_in6 cfg_addr;
 static unsigned int cfg_rx_buf_len;
 static bool cfg_dry_run;
+static int cfg_num_threads = 1;
 
 static char *payload;
 
+#define CONNS_PER_THREAD	4
+
 struct thread_ctx {
 	struct io_uring		ring;
 	void			*area_ptr;
@@ -379,7 +383,7 @@ static void run_server(void)
 		error(1, 0, "test failed\n");
 }
 
-static void run_client(void)
+static void *client_worker(void *arg)
 {
 	ssize_t to_send = cfg_send_size;
 	ssize_t sent = 0;
@@ -405,12 +409,37 @@ static void run_client(void)
 	}
 
 	close(fd);
+	return NULL;
+}
+
+static void run_client(void)
+{
+	int conns_per_thread = cfg_num_threads > 1 ? CONNS_PER_THREAD : 1;
+	int total_conns = conns_per_thread * cfg_num_threads;
+	pthread_t *threads;
+	int i, ret;
+
+	threads = calloc(total_conns, sizeof(*threads));
+	if (!threads)
+		error(1, 0, "calloc()");
+
+	for (i = 0; i < total_conns; i++) {
+		ret = pthread_create(&threads[i], NULL, client_worker, NULL);
+		if (ret)
+			error(1, ret, "pthread_create()");
+	}
+
+	for (i = 0; i < total_conns; i++)
+		pthread_join(threads[i], NULL);
+
+	free(threads);
 }
 
 static void usage(const char *filepath)
 {
 	error(1, 0, "Usage: %s (-4|-6) (-s|-c) -h<server_ip> -p<port> "
-		    "-l<payload_size> -i<ifname> -q<rxq_id>", filepath);
+		    "-l<payload_size> -i<ifname> -q<rxq_id> -t<num_threads>",
+		    filepath);
 }
 
 static void parse_opts(int argc, char **argv)
@@ -428,7 +457,7 @@ static void parse_opts(int argc, char **argv)
 		usage(argv[0]);
 	cfg_payload_len = max_payload_len;
 
-	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:d")) != -1) {
+	while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:dt:")) != -1) {
 		switch (c) {
 		case 's':
 			if (cfg_client)
@@ -469,6 +498,9 @@ static void parse_opts(int argc, char **argv)
 		case 'd':
 			cfg_dry_run = true;
 			break;
+		case 't':
+			cfg_num_threads = strtoul(optarg, NULL, 0);
+			break;
 		}
 	}
 
-- 
2.53.0-Meta