Add test to fill the ring buffer

test/emu/ovni/CMakeLists.txt

@@ -9,5 +9,7 @@ endif()
 ovni_test(flush.c)
 ovni_test(sort.c SORT)
 ovni_test(empty-sort.c SORT)
+ovni_test(sort-first-and-full-ring.c SORT
+  SHOULD_FAIL REGEX "cannot find a event previous to clock")
 ovni_test(mp-simple.c MP)
 ovni_test(mp-rank.c MP)

test/emu/ovni/sort-first-and-full-ring.c

@@ -0,0 +1,79 @@
+/* Copyright (c) 2021-2022 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#define _POSIX_C_SOURCE 200112L
+#define _GNU_SOURCE
+
+#include <limits.h>
+#include <linux/limits.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "compat.h"
+#include "common.h"
+#include "ovni.h"
+
+static inline void
+init(void)
+{
+	char hostname[HOST_NAME_MAX];
+
+	if (gethostname(hostname, HOST_NAME_MAX) != 0) {
+		perror("gethostname failed");
+		exit(EXIT_FAILURE);
+	}
+
+	ovni_proc_init(0, hostname, getpid());
+	ovni_thread_init(gettid());
+	ovni_add_cpu(0, 0);
+}
+
+static void
+emit(char *mcv, int64_t clock)
+{
+	struct ovni_ev ev = {0};
+	ovni_ev_set_mcv(&ev, mcv);
+	ovni_ev_set_clock(&ev, clock);
+	ovni_ev_emit(&ev);
+}
+
+int
+main(void)
+{
+	init();
+
+	/* Leave some room to prevent clashes */
+	usleep(100); /* 100000 us */
+
+	int64_t t0 = ovni_clock_now();
+
+	emit("OU[", t0);
+
+	/* Fill the ring buffer */
+	long n = 100000 + 10;
+
+	err("using n=%ld events\n", n);
+
+	/* Go back 100 ns for each event (with some space) */
+	int64_t t = t0 - (n + 10) * 100;
+
+	for (long i = 0; i < n; i++) {
+		emit("OB.", t);
+		t += 33;
+	}
+
+	emit("OU]", ovni_clock_now());
+	t += 33;
+
+	if (t >= t0)
+		die("bad timming\n");
+
+	ovni_flush();
+	ovni_proc_fini();
+
+	return 0;
+}