From b2d91391b33c09ea71bec92b5585f593de690cee Mon Sep 17 00:00:00 2001
From: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
Date: Fri, 6 Sep 2024 11:58:19 +0200
Subject: [PATCH] Add sort-into-previous-region emu test

---
 test/emu/ovni/CMakeLists.txt                  |  1 +
 test/emu/ovni/sort-into-previous-region.c     | 74 +++++++++++++++++++
 .../ovni/sort-into-previous-region.driver.sh  | 25 +++++++
 3 files changed, 100 insertions(+)
 create mode 100644 test/emu/ovni/sort-into-previous-region.c
 create mode 100644 test/emu/ovni/sort-into-previous-region.driver.sh

diff --git a/test/emu/ovni/CMakeLists.txt b/test/emu/ovni/CMakeLists.txt
index b7559f3..e011ce2 100644
--- a/test/emu/ovni/CMakeLists.txt
+++ b/test/emu/ovni/CMakeLists.txt
@@ -5,6 +5,7 @@ test_emu(flush-overhead.c DISABLED)
 test_emu(flush.c)
 test_emu(sort.c SORT)
 test_emu(sort-flush.c SORT)
+test_emu(sort-into-previous-region.c SORT DRIVER "sort-into-previous-region.driver.sh")
 test_emu(empty-sort.c SORT)
 test_emu(sort-first-and-full-ring.c SORT
   SHOULD_FAIL REGEX "cannot find a event previous to clock")
diff --git a/test/emu/ovni/sort-into-previous-region.c b/test/emu/ovni/sort-into-previous-region.c
new file mode 100644
index 0000000..01142f1
--- /dev/null
+++ b/test/emu/ovni/sort-into-previous-region.c
@@ -0,0 +1,74 @@
+/* Copyright (c) 2024 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#include <stdint.h>
+#include "compat.h"
+#include "instr.h"
+#include "ovni.h"
+
+/* Test the case in which events from a secondary unsorted region are
+ * introduced before the previous unsorted region:
+ *
+ * [bbbb][BBbb]
+ * bbbbBB[]bb[]
+ *
+ * The events B contain 16 bytes of payload, so pointer to events in previous
+ * positions are now pointing to garbage.
+ *
+ * See: https://pm.bsc.es/gitlab/rarias/ovni/-/issues/199
+ */
+
+static void
+emit(char *mcv, int64_t clock, int size)
+{
+	struct ovni_ev ev = {0};
+	ovni_ev_set_mcv(&ev, mcv);
+	ovni_ev_set_clock(&ev, clock);
+
+	if (size) {
+		uint8_t buf[64] = { 0 };
+		ovni_payload_add(&ev, buf, size);
+	}
+
+	ovni_ev_emit(&ev);
+}
+
+int
+main(void)
+{
+	instr_start(0, 1);
+
+	/* Leave some room to prevent clashes */
+	sleep_us(100); /* 100000 us */
+	int64_t t0 = ovni_clock_now();
+	sleep_us(100); /* 100000 us */
+
+	/* We want it to end like this:
+	 *
+	 * t0  +1  +2  +3  +4  +5  +6  +7  +8  +9  +10 +11
+	 * b   b   b   b   B   B   [   ]   b   b   [   ]
+	 *
+	 * But we emit it like this:
+	 *
+	 * +6  +0  +1  +2  +3  +7  +10 +4  +5  +8  +9  +11
+	 * [   b   b   b   b   ]   [   B   B   b   b   ]
+	 */
+
+	emit("OU[", t0 + 6, 0);
+	emit("OB.", t0 + 0, 0);
+	emit("OB.", t0 + 1, 0);
+	emit("OB.", t0 + 2, 0);
+	emit("OB.", t0 + 3, 0);
+	emit("OU]", t0 + 7, 0);
+
+	emit("OU[", t0 + 10, 0);
+	emit("OB.", t0 + 4, 16);
+	emit("OB.", t0 + 5, 16);
+	emit("OB.", t0 + 8, 0);
+	emit("OB.", t0 + 9, 0);
+	emit("OU]", t0 + 11, 0);
+
+	instr_end();
+
+	return 0;
+}
diff --git a/test/emu/ovni/sort-into-previous-region.driver.sh b/test/emu/ovni/sort-into-previous-region.driver.sh
new file mode 100644
index 0000000..042f271
--- /dev/null
+++ b/test/emu/ovni/sort-into-previous-region.driver.sh
@@ -0,0 +1,25 @@
+target=$OVNI_TEST_BIN
+
+$target
+ovnisort ovni
+ovnidump ovni
+ovnidump ovni | awk 'NR == 1 {next} NR==2{t=$1} {print $1-t,$2} NR==13{exit}' > found
+
+cat > expected <<EOF
+0 OB.
+1 OB.
+2 OB.
+3 OB.
+4 OB.
+5 OB.
+6 OU[
+7 OU]
+8 OB.
+9 OB.
+10 OU[
+11 OU]
+EOF
+
+diff -s found expected
+
+ovniemu ovni