purego: remove pooling of syscall (#452) (#453)

(cherry picked from commit 11272d2804cdba6e4e4e6635e80f035a14f9ccbe)

Co-authored-by: TotallyGamerJet <TotallyGamerJet@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

commit: eaff005fcda6dae0d855da9c6ee3efb7e775ddad
author: Hajime Hoshi · 5mo ago · 2026-05-24 13:19 UTC
committer: GitHub · 5mo ago · 2026-05-24 13:19 UTC
parent: bb9b1f4
signature: GPG UnverifiedB5690EEEBB952194 The key is unknown
refs: tag: upstream-v0.10.1tag: v0.10.1

3 files · +37 -12

M func.go +1 -8


@@ -10,7 +10,6 @@ import (
10	10		"math"
11	11		"reflect"
12	12		"runtime"
13		-	"sync"
14	13		"unsafe"
15	14
16	15		"github.com/ebitengine/purego/internal/strings"

@@ -22,10 +21,6 @@ const (
22	21		align8ByteSize = 8 // 8-byte alignment boundary
23	22		)
24	23
25		-	var thePool = sync.Pool{New: func() any {
26		-	return new(syscall15Args)
27		-	}}
28		-
29	24		// RegisterLibFunc is a wrapper around RegisterFunc that uses the C function returned from Dlsym(handle, name).
30	25		// It panics if it can't find the name symbol.
31	26		func RegisterLibFunc(fptr any, handle uintptr, name string) {

@@ -310,8 +305,7 @@ func RegisterFunc(fptr any, cfn uintptr) {
310	305		keepAlive = addValue(v, keepAlive, addInt, addFloat, addStack, &numInts, &numFloats, &numStack)
311	306		}
312	307
313		-	syscall := thePool.Get().(*syscall15Args)
314		-	defer thePool.Put(syscall)
	308	+	syscall := &syscall15Args{}
315	309
316	310		if runtime.GOARCH == "loong64" \|\| runtime.GOARCH == "ppc64le" \|\| runtime.GOARCH == "riscv64" \|\| runtime.GOARCH == "s390x" {
317	311		syscall.Set(cfn, sysargs[:], floats[:], 0)

@@ -321,7 +315,6 @@ func RegisterFunc(fptr any, cfn uintptr) {
321	315		syscall.Set(cfn, sysargs[:], floats[:], arm64_r8)
322	316		runtime_cgocall(syscall15XABI0, unsafe.Pointer(syscall))
323	317		} else {
324		-	*syscall = syscall15Args{}
325	318		// This is a fallback for Windows amd64, 386, and arm. Note this may not support floats
326	319		syscall.a1, syscall.a2, _ = syscall_syscall15X(cfn, sysargs[0], sysargs[1], sysargs[2], sysargs[3], sysargs[4],
327	320		sysargs[5], sysargs[6], sysargs[7], sysargs[8], sysargs[9], sysargs[10], sysargs[11],

 	"math"
 	"reflect"
 	"runtime"
-	"sync"
 	"unsafe"
 	"github.com/ebitengine/purego/internal/strings"
 	align8ByteSize = 8 // 8-byte alignment boundary
 )
-var thePool = sync.Pool{New: func() any {
-	return new(syscall15Args)
-}}
 // RegisterLibFunc is a wrapper around RegisterFunc that uses the C function returned from Dlsym(handle, name).
 // It panics if it can't find the name symbol.
 func RegisterLibFunc(fptr any, handle uintptr, name string) {
 			keepAlive = addValue(v, keepAlive, addInt, addFloat, addStack, &numInts, &numFloats, &numStack)
 		}
-		syscall := thePool.Get().(*syscall15Args)
+		syscall := &syscall15Args{}
-		defer thePool.Put(syscall)
 		if runtime.GOARCH == "loong64" || runtime.GOARCH == "ppc64le" || runtime.GOARCH == "riscv64" || runtime.GOARCH == "s390x" {
 			syscall.Set(cfn, sysargs[:], floats[:], 0)
 			syscall.Set(cfn, sysargs[:], floats[:], arm64_r8)
 			runtime_cgocall(syscall15XABI0, unsafe.Pointer(syscall))
 		} else {
-			*syscall = syscall15Args{}
 			// This is a fallback for Windows amd64, 386, and arm. Note this may not support floats
 			syscall.a1, syscall.a2, _ = syscall_syscall15X(cfn, sysargs[0], sysargs[1], sysargs[2], sysargs[3], sysargs[4],
 				sysargs[5], sysargs[6], sysargs[7], sysargs[8], sysargs[9], sysargs[10], sysargs[11],

M func_test.go +35 -0


@@ -11,6 +11,7 @@ import (
11	11		"path/filepath"
12	12		"runtime"
13	13		"strings"
	14	+	"sync"
14	15		"testing"
15	16		"unsafe"
16	17

@@ -35,6 +36,40 @@ func getSystemLibrary() (string, error) {
35	36		}
36	37		}
37	38
	39	+	func TestRegisterFunc_ConcurrentPointerReturn(t *testing.T) {
	40	+	library, err := getSystemLibrary()
	41	+	if err != nil {
	42	+	t.Fatalf("couldn't get system library: %s", err)
	43	+	}
	44	+	libc, err := load.OpenLibrary(library)
	45	+	if err != nil {
	46	+	t.Fatalf("failed to dlopen: %s", err)
	47	+	}
	48	+
	49	+	var alloc func(uint64) *byte
	50	+	var free func(*byte)
	51	+	purego.RegisterLibFunc(&alloc, libc, "malloc")
	52	+	purego.RegisterLibFunc(&free, libc, "free")
	53	+
	54	+	var wg sync.WaitGroup
	55	+
	56	+	for i := 0; i < runtime.NumCPU(); i++ {
	57	+	wg.Add(1)
	58	+	go func(id int) {
	59	+	defer wg.Done()
	60	+	for j := 0; j < 400_000; j++ {
	61	+	ptr := alloc(5)
	62	+	if ptr == nil {
	63	+	continue
	64	+	}
	65	+	free(ptr)
	66	+	}
	67	+	}(i)
	68	+	}
	69	+
	70	+	wg.Wait()
	71	+	}
	72	+
38	73		func TestRegisterFunc(t *testing.T) {
39	74		library, err := getSystemLibrary()
40	75		if err != nil {


@@ -11,6 +11,7 @@ import (
11	"path/filepath"	11		"path/filepath"
12	"runtime"	12		"runtime"
13	"strings"	13		"strings"
		14	+	"sync"
14	"testing"	15		"testing"
15	"unsafe"	16		"unsafe"
16		17

@@ -35,6 +36,40 @@ func getSystemLibrary() (string, error) {
35	}	36		}
36	}	37		}
37		38
		39	+	func TestRegisterFunc_ConcurrentPointerReturn(t *testing.T) {
		40	+	library, err := getSystemLibrary()
		41	+	if err != nil {
		42	+	t.Fatalf("couldn't get system library: %s", err)
		43	+	}
		44	+	libc, err := load.OpenLibrary(library)
		45	+	if err != nil {
		46	+	t.Fatalf("failed to dlopen: %s", err)
		47	+	}
		48	+
		49	+	var alloc func(uint64) *byte
		50	+	var free func(*byte)
		51	+	purego.RegisterLibFunc(&alloc, libc, "malloc")
		52	+	purego.RegisterLibFunc(&free, libc, "free")
		53	+
		54	+	var wg sync.WaitGroup
		55	+
		56	+	for i := 0; i < runtime.NumCPU(); i++ {
		57	+	wg.Add(1)
		58	+	go func(id int) {
		59	+	defer wg.Done()
		60	+	for j := 0; j < 400_000; j++ {
		61	+	ptr := alloc(5)
		62	+	if ptr == nil {
		63	+	continue
		64	+	}
		65	+	free(ptr)
		66	+	}
		67	+	}(i)
		68	+	}
		69	+
		70	+	wg.Wait()
		71	+	}
		72	+
38	func TestRegisterFunc(t *testing.T) {	73		func TestRegisterFunc(t *testing.T) {
39	library, err := getSystemLibrary()	74		library, err := getSystemLibrary()
40	if err != nil {	75		if err != nil {

M syscall_sysv.go +1 -4


@@ -16,10 +16,7 @@ import (
16	16		var syscall15XABI0 uintptr
17	17
18	18		func syscall_syscall15X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2, err uintptr) {
19		-	args := thePool.Get().(*syscall15Args)
20		-	defer thePool.Put(args)
21		-
22		-	*args = syscall15Args{
	19	+	args := &syscall15Args{
23	20		fn: fn,
24	21		a1: a1, a2: a2, a3: a3, a4: a4, a5: a5, a6: a6, a7: a7, a8: a8,
25	22		a9: a9, a10: a10, a11: a11, a12: a12, a13: a13, a14: a14, a15: a15,

 var syscall15XABI0 uintptr
 func syscall_syscall15X(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2, err uintptr) {
-	args := thePool.Get().(*syscall15Args)
+	args := &syscall15Args{
-	defer thePool.Put(args)
-	*args = syscall15Args{
 		fn: fn,
 		a1: a1, a2: a2, a3: a3, a4: a4, a5: a5, a6: a6, a7: a7, a8: a8,
 		a9: a9, a10: a10, a11: a11, a12: a12, a13: a13, a14: a14, a15: a15,