4 files changed, 138 insertions, 0 deletions

diff --git a/t/helper/test-fsmonitor-client.c b/t/helper/test-fsmonitor-client.c
index 3062c8a3c2..54a4856c48 100644
--- a/t/helper/test-fsmonitor-client.c
+++ b/t/helper/test-fsmonitor-client.c
@@ -7,6 +7,8 @@
 #include "cache.h"
 #include "parse-options.h"
 #include "fsmonitor-ipc.h"
+#include "thread-utils.h"
+#include "trace2.h"
 
 #ifndef HAVE_FSMONITOR_DAEMON_BACKEND
 int cmd__fsmonitor_client(int argc, const char **argv)
@@ -79,20 +81,121 @@ static int do_send_flush(void)
 	return 0;
 }
 
+struct hammer_thread_data
+{
+	pthread_t pthread_id;
+	int thread_nr;
+
+	int nr_requests;
+	const char *token;
+
+	int sum_successful;
+	int sum_errors;
+};
+
+static void *hammer_thread_proc(void *_hammer_thread_data)
+{
+	struct hammer_thread_data *data = _hammer_thread_data;
+	struct strbuf answer = STRBUF_INIT;
+	int k;
+	int ret;
+
+	trace2_thread_start("hammer");
+
+	for (k = 0; k < data->nr_requests; k++) {
+		strbuf_reset(&answer);
+
+		ret = fsmonitor_ipc__send_query(data->token, &answer);
+		if (ret < 0)
+			data->sum_errors++;
+		else
+			data->sum_successful++;
+	}
+
+	strbuf_release(&answer);
+	trace2_thread_exit();
+	return NULL;
+}
+
+/*
+ * Start a pool of client threads that will each send a series of
+ * commands to the daemon.
+ *
+ * The goal is to overload the daemon with a sustained series of
+ * concurrent requests.
+ */
+static int do_hammer(const char *token, int nr_threads, int nr_requests)
+{
+	struct hammer_thread_data *data = NULL;
+	int k;
+	int sum_join_errors = 0;
+	int sum_commands = 0;
+	int sum_errors = 0;
+
+	if (!token || !*token)
+		token = get_token_from_index();
+	if (nr_threads < 1)
+		nr_threads = 1;
+	if (nr_requests < 1)
+		nr_requests = 1;
+
+	CALLOC_ARRAY(data, nr_threads);
+
+	for (k = 0; k < nr_threads; k++) {
+		struct hammer_thread_data *p = &data[k];
+		p->thread_nr = k;
+		p->nr_requests = nr_requests;
+		p->token = token;
+
+		if (pthread_create(&p->pthread_id, NULL, hammer_thread_proc, p)) {
+			warning("failed to create thread[%d] skipping remainder", k);
+			nr_threads = k;
+			break;
+		}
+	}
+
+	for (k = 0; k < nr_threads; k++) {
+		struct hammer_thread_data *p = &data[k];
+
+		if (pthread_join(p->pthread_id, NULL))
+			sum_join_errors++;
+		sum_commands += p->sum_successful;
+		sum_errors += p->sum_errors;
+	}
+
+	fprintf(stderr, "HAMMER: [threads %d][requests %d] [ok %d][err %d][join %d]\n",
+		nr_threads, nr_requests, sum_commands, sum_errors, sum_join_errors);
+
+	free(data);
+
+	/*
+	 * Return an error if any of the _send_query requests failed.
+	 * We don't care about thread create/join errors.
+	 */
+	return sum_errors > 0;
+}
+
 int cmd__fsmonitor_client(int argc, const char **argv)
 {
 	const char *subcmd;
 	const char *token = NULL;
+	int nr_threads = 1;
+	int nr_requests = 1;
 
 	const char * const fsmonitor_client_usage[] = {
 		"test-tool fsmonitor-client query [<token>]",
 		"test-tool fsmonitor-client flush",
+		"test-tool fsmonitor-client hammer [<token>] [<threads>] [<requests>]",
 		NULL,
 	};
 
 	struct option options[] = {
 		OPT_STRING(0, "token", &token, "token",
 			   "command token to send to the server"),
+
+		OPT_INTEGER(0, "threads", &nr_threads, "number of client threads"),
+		OPT_INTEGER(0, "requests", &nr_requests, "number of requests per thread"),
+
 		OPT_END()
 	};
 
@@ -111,6 +214,9 @@ int cmd__fsmonitor_client(int argc, const char **argv)
 	if (!strcmp(subcmd, "flush"))
 		return !!do_send_flush();
 
+	if (!strcmp(subcmd, "hammer"))
+		return !!do_hammer(token, nr_threads, nr_requests);
+
 	die("Unhandled subcommand: '%s'", subcmd);
 }
 #endif
diff --git a/t/helper/test-hexdump.c b/t/helper/test-hexdump.c
new file mode 100644
index 0000000000..811e89c1bc
--- /dev/null
+++ b/t/helper/test-hexdump.c
@@ -0,0 +1,30 @@
+#include "test-tool.h"
+#include "git-compat-util.h"
+
+/*
+ * Read stdin and print a hexdump to stdout.
+ */
+int cmd__hexdump(int argc, const char **argv)
+{
+	char buf[1024];
+	ssize_t i, len;
+	int have_data = 0;
+
+	for (;;) {
+		len = xread(0, buf, sizeof(buf));
+		if (len < 0)
+			die_errno("failure reading stdin");
+		if (!len)
+			break;
+
+		have_data = 1;
+
+		for (i = 0; i < len; i++)
+			printf("%02x ", (unsigned char)buf[i]);
+	}
+
+	if (have_data)
+		putchar('\n');
+
+	return 0;
+}
diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c
index d2eacd302d..318fdbab0c 100644
--- a/t/helper/test-tool.c
+++ b/t/helper/test-tool.c
@@ -38,6 +38,7 @@ static struct test_cmd cmds[] = {
 	{ "getcwd", cmd__getcwd },
 	{ "hashmap", cmd__hashmap },
 	{ "hash-speed", cmd__hash_speed },
+	{ "hexdump", cmd__hexdump },
 	{ "index-version", cmd__index_version },
 	{ "json-writer", cmd__json_writer },
 	{ "lazy-init-name-hash", cmd__lazy_init_name_hash },
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index 960cc27ef7..bb79927163 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -29,6 +29,7 @@ int cmd__genzeros(int argc, const char **argv);
 int cmd__getcwd(int argc, const char **argv);
 int cmd__hashmap(int argc, const char **argv);
 int cmd__hash_speed(int argc, const char **argv);
+int cmd__hexdump(int argc, const char **argv);
 int cmd__index_version(int argc, const char **argv);
 int cmd__json_writer(int argc, const char **argv);
 int cmd__lazy_init_name_hash(int argc, const char **argv);