[RFC,3/4] selftests/rseq: Implement sched state test program
Commit Message
This is a small test program with can be altered to show whether the
target thread is on-cpu or not, dependending on whether it loops on
poll() or does a busy-loop.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
tools/testing/selftests/rseq/.gitignore | 1 +
tools/testing/selftests/rseq/Makefile | 2 +-
.../testing/selftests/rseq/sched_state_test.c | 71 +++++++++++++++++++
3 files changed, 73 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/rseq/sched_state_test.c
@@ -9,3 +9,4 @@ param_test_compare_twice
param_test_mm_cid
param_test_mm_cid_benchmark
param_test_mm_cid_compare_twice
+sched_state_test
@@ -14,7 +14,7 @@ OVERRIDE_TARGETS = 1
TEST_GEN_PROGS = basic_test basic_percpu_ops_test basic_percpu_ops_mm_cid_test param_test \
param_test_benchmark param_test_compare_twice param_test_mm_cid \
- param_test_mm_cid_benchmark param_test_mm_cid_compare_twice
+ param_test_mm_cid_benchmark param_test_mm_cid_compare_twice sched_state_test
TEST_GEN_PROGS_EXTENDED = librseq.so
new file mode 100644
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: LGPL-2.1
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <poll.h>
+
+#include "rseq.h"
+
+static struct rseq_abi *target_thread;
+
+//TODO:
+//Use rseq c.s. and rseq fence to protect access to remote thread's rseq_abi.
+
+static
+void show_sched_state(struct rseq_abi *rseq_thread)
+{
+ uint32_t state;
+
+ state = rseq_thread->sched_state;
+ printf("Target thread: ON_CPU=%d\n", !!(state & RSEQ_SCHED_STATE_ON_CPU));
+}
+
+
+static
+void *test_thread(void *arg)
+{
+ int i;
+
+ for (i = 0; i < 1000; i++) {
+ show_sched_state(target_thread);
+ (void) poll(NULL, 0, 100);
+ }
+ return NULL;
+}
+
+int main(int argc, char **argv)
+{
+ pthread_t test_thread_id;
+ int i;
+
+ if (rseq_register_current_thread()) {
+ fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ goto init_thread_error;
+ }
+ target_thread = rseq_get_abi();
+
+ pthread_create(&test_thread_id, NULL, test_thread, NULL);
+
+ for (i = 0; i < 1000000000; i++)
+ rseq_barrier();
+ //for (i = 0; i < 10000; i++)
+ // (void) poll(NULL, 0, 75);
+
+ pthread_join(test_thread_id, NULL);
+
+ if (rseq_unregister_current_thread()) {
+ fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
+ errno, strerror(errno));
+ goto init_thread_error;
+ }
+ return 0;
+
+init_thread_error:
+ return -1;
+}