test(syscall): prove pointer liveness across Syscall6

commit: 9fea51b06733dd19f9573dcb56c9983948b45263
author: brice · 25d ago · 2026-09-27 18:01 UTC
committer: brice · 25d ago · 2026-09-27 18:45 UTC
parent: d3eb2c6
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email
checks: 0/25
refs: tag: v0.13.0-bnema.1

2 files · +92 -0

A syscall_fixed_test.go +82 -0

@@ -0,0 +1,82 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
	3	+
	4	+	//go:build !windows && !plan9
	5	+
	6	+	package purego_test
	7	+
	8	+	import (
	9	+	"path/filepath"
	10	+	"runtime"
	11	+	"runtime/debug"
	12	+	"sync"
	13	+	"testing"
	14	+	"unsafe"
	15	+
	16	+	"github.com/bnema/purego"
	17	+	"github.com/bnema/purego/internal/load"
	18	+	)
	19	+
	20	+	//go:noinline
	21	+	func writeDeep(sym uintptr, depth int) bool {
	22	+	var pad [1024]byte
	23	+	pad[0] = byte(depth)
	24	+	if depth > 0 {
	25	+	ok := writeDeep(sym, depth-1)
	26	+	runtime.KeepAlive(pad)
	27	+	return ok
	28	+	}
	29	+	var local uint64
	30	+	purego.Syscall6(sym, uintptr(unsafe.Pointer(&local)), 42, 0, 0, 0, 0)
	31	+	runtime.KeepAlive(&local)
	32	+	runtime.KeepAlive(pad)
	33	+	return local == 42
	34	+	}
	35	+
	36	+	func TestSyscall6PointerLiveness(t *testing.T) {
	37	+	libFile := filepath.Join(t.TempDir(), "libbenchmark.so")
	38	+	if err := buildSharedLib(t, "CC", libFile, filepath.Join("testdata", "benchmarktest", "benchmark.c")); err != nil {
	39	+	t.Fatal(err)
	40	+	}
	41	+	lib, err := load.OpenLibrary(libFile)
	42	+	if err != nil {
	43	+	t.Fatal(err)
	44	+	}
	45	+	defer load.CloseLibrary(lib)
	46	+	sym, err := load.OpenSymbol(lib, "write_through")
	47	+	if err != nil {
	48	+	t.Fatal(err)
	49	+	}
	50	+
	51	+	stop := make(chan struct{})
	52	+	var wg sync.WaitGroup
	53	+	wg.Add(1)
	54	+	go func() {
	55	+	defer wg.Done()
	56	+	for {
	57	+	select {
	58	+	case <-stop:
	59	+	return
	60	+	default:
	61	+	runtime.GC()
	62	+	debug.FreeOSMemory()
	63	+	}
	64	+	}
	65	+	}()
	66	+	defer func() { close(stop); wg.Wait() }()
	67	+
	68	+	for i := 0; i < 32; i++ {
	69	+	if !writeDeep(sym, 0) {
	70	+	t.Fatal("stack local not updated")
	71	+	}
	72	+	}
	73	+	if !writeDeep(sym, 64) {
	74	+	t.Fatal("deep stack local not updated")
	75	+	}
	76	+	heap := new(uint64)
	77	+	purego.Syscall6(sym, uintptr(unsafe.Pointer(heap)), 42, 0, 0, 0, 0)
	78	+	runtime.KeepAlive(heap)
	79	+	if *heap != 42 {
	80	+	t.Fatalf("heap value = %d", *heap)
	81	+	}
	82	+	}

@@ -0,0 +1,82 @@
	1	+	// SPDX-License-Identifier: Apache-2.0
	2	+	// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
	3	+
	4	+	//go:build !windows && !plan9
	5	+
	6	+	package purego_test
	7	+
	8	+	import (
	9	+	"path/filepath"
	10	+	"runtime"
	11	+	"runtime/debug"
	12	+	"sync"
	13	+	"testing"
	14	+	"unsafe"
	15	+
	16	+	"github.com/bnema/purego"
	17	+	"github.com/bnema/purego/internal/load"
	18	+	)
	19	+
	20	+	//go:noinline
	21	+	func writeDeep(sym uintptr, depth int) bool {
	22	+	var pad [1024]byte
	23	+	pad[0] = byte(depth)
	24	+	if depth > 0 {
	25	+	ok := writeDeep(sym, depth-1)
	26	+	runtime.KeepAlive(pad)
	27	+	return ok
	28	+	}
	29	+	var local uint64
	30	+	purego.Syscall6(sym, uintptr(unsafe.Pointer(&local)), 42, 0, 0, 0, 0)
	31	+	runtime.KeepAlive(&local)
	32	+	runtime.KeepAlive(pad)
	33	+	return local == 42
	34	+	}
	35	+
	36	+	func TestSyscall6PointerLiveness(t *testing.T) {
	37	+	libFile := filepath.Join(t.TempDir(), "libbenchmark.so")
	38	+	if err := buildSharedLib(t, "CC", libFile, filepath.Join("testdata", "benchmarktest", "benchmark.c")); err != nil {
	39	+	t.Fatal(err)
	40	+	}
	41	+	lib, err := load.OpenLibrary(libFile)
	42	+	if err != nil {
	43	+	t.Fatal(err)
	44	+	}
	45	+	defer load.CloseLibrary(lib)
	46	+	sym, err := load.OpenSymbol(lib, "write_through")
	47	+	if err != nil {
	48	+	t.Fatal(err)
	49	+	}
	50	+
	51	+	stop := make(chan struct{})
	52	+	var wg sync.WaitGroup
	53	+	wg.Add(1)
	54	+	go func() {
	55	+	defer wg.Done()
	56	+	for {
	57	+	select {
	58	+	case <-stop:
	59	+	return
	60	+	default:
	61	+	runtime.GC()
	62	+	debug.FreeOSMemory()
	63	+	}
	64	+	}
	65	+	}()
	66	+	defer func() { close(stop); wg.Wait() }()
	67	+
	68	+	for i := 0; i < 32; i++ {
	69	+	if !writeDeep(sym, 0) {
	70	+	t.Fatal("stack local not updated")
	71	+	}
	72	+	}
	73	+	if !writeDeep(sym, 64) {
	74	+	t.Fatal("deep stack local not updated")
	75	+	}
	76	+	heap := new(uint64)
	77	+	purego.Syscall6(sym, uintptr(unsafe.Pointer(heap)), 42, 0, 0, 0, 0)
	78	+	runtime.KeepAlive(heap)
	79	+	if *heap != 42 {
	80	+	t.Fatalf("heap value = %d", *heap)
	81	+	}
	82	+	}

M testdata/benchmarktest/benchmark.c +10 -0


@@ -2,6 +2,16 @@
2	2		// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
3	3
4	4		#include <stdint.h>
	5	+	#include <time.h>
	6	+
	7	+	void write_through(uint64_t *p, uint64_t v) {
	8	+	*p = v;
	9	+	struct timespec start, now;
	10	+	clock_gettime(CLOCK_MONOTONIC, &start);
	11	+	do {
	12	+	clock_gettime(CLOCK_MONOTONIC, &now);
	13	+	} while ((now.tv_sec - start.tv_sec) * 1000000000L + now.tv_nsec - start.tv_nsec < 2000000L);
	14	+	}
5	15
6	16		int64_t sum1_c(int64_t a1) { return a1; }
7	17


@@ -2,6 +2,16 @@
2	// SPDX-FileCopyrightText: 2026 The Ebitengine Authors	2		// SPDX-FileCopyrightText: 2026 The Ebitengine Authors
3		3
4	#include <stdint.h>	4		#include <stdint.h>
		5	+	#include <time.h>
		6	+
		7	+	void write_through(uint64_t *p, uint64_t v) {
		8	+	*p = v;
		9	+	struct timespec start, now;
		10	+	clock_gettime(CLOCK_MONOTONIC, &start);
		11	+	do {
		12	+	clock_gettime(CLOCK_MONOTONIC, &now);
		13	+	} while ((now.tv_sec - start.tv_sec) * 1000000000L + now.tv_nsec - start.tv_nsec < 2000000L);
		14	+	}
5		15
6	int64_t sum1_c(int64_t a1) { return a1; }	16		int64_t sum1_c(int64_t a1) { return a1; }
7		17