util: implement GetTotalMemory for mac and windows (#6272)

Author: algorandskiy

util/util.go

@@ -21,7 +21,6 @@ package util
 
 import (
 	"fmt"
-	"runtime"
 	"syscall"
 )
 
@@ -74,18 +73,7 @@ func GetCurrentProcessTimes() (utime int64, stime int64, err error) {
 	return
 }
 
-// GetTotalMemory gets total system memory on Linux systems
+// GetTotalMemory gets total system memory
 func GetTotalMemory() uint64 {
-	switch runtime.GOOS {
-	case "linux":
-		// Use sysinfo on Linux
-		var si syscall.Sysinfo_t
-		err := syscall.Sysinfo(&si)
-		if err != nil {
-			return 0
-		}
-		return si.Totalram
-	default:
-		return 0
-	}
+	return getTotalMemory()
 }

util/util_darwin.go

@@ -0,0 +1,34 @@
+// Copyright (C) 2019-2025 Algorand, Inc.
+// This file is part of go-algorand
+//
+// go-algorand is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// go-algorand is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with go-algorand.  If not, see <https://www.gnu.org/licenses/>.
+
+package util
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func getTotalMemory() uint64 {
+	out, err := syscall.Sysctl("hw.memsize")
+	if err != nil {
+		return 0
+	}
+	b := []byte(out)
+	if len(b) < 8 {
+		b = append(b, 0)
+	}
+	return *(*uint64)(unsafe.Pointer(&b[0]))
+}

util/util_linux.go

@@ -0,0 +1,31 @@
+// Copyright (C) 2019-2025 Algorand, Inc.
+// This file is part of go-algorand
+//
+// go-algorand is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// go-algorand is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with go-algorand.  If not, see <https://www.gnu.org/licenses/>.
+
+package util
+
+import (
+	"syscall"
+)
+
+func getTotalMemory() uint64 {
+	var si syscall.Sysinfo_t
+	err := syscall.Sysinfo(&si)
+	if err != nil {
+		return 0
+	}
+	// support 32-bit systems where Totalram is uint32
+	return uint64(si.Totalram) * uint64(si.Unit)
+}

util/util_test.go

@@ -0,0 +1,32 @@
+// Copyright (C) 2019-2025 Algorand, Inc.
+// This file is part of go-algorand
+//
+// go-algorand is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// go-algorand is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with go-algorand.  If not, see <https://www.gnu.org/licenses/>.
+
+package util
+
+import (
+	"testing"
+
+	"github.com/algorand/go-algorand/test/partitiontest"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetTotalMemory(t *testing.T) {
+	partitiontest.PartitionTest(t)
+	t.Parallel()
+
+	mem := GetTotalMemory()
+	require.Greater(t, mem, uint64(0))
+}

util/util_windows.go

@@ -21,6 +21,7 @@ import (
 	"math"
 	"syscall"
 	"time"
+	"unsafe"
 )
 
 /* misc */
@@ -70,7 +71,38 @@ func filetimeToDuration(ft *syscall.Filetime) time.Duration {
 	return time.Duration(n * 100)
 }
 
-// GetTotalMemory gets total system memory, returns 0 on Windows
+// GetTotalMemory gets total system memory on Windows
 func GetTotalMemory() uint64 {
-	return 0
+	var memoryStatusEx MemoryStatusEx
+	memoryStatusEx.dwLength = uint32(unsafe.Sizeof(memoryStatusEx))
+
+	if err := globalMemoryStatusEx(&memoryStatusEx); err != nil {
+		return 0
+	}
+	return memoryStatusEx.ullTotalPhys
+}
+
+type MemoryStatusEx struct {
+	dwLength                uint32
+	dwMemoryLoad            uint32
+	ullTotalPhys            uint64
+	ullAvailPhys            uint64
+	ullTotalPageFile        uint64
+	ullAvailPageFile        uint64
+	ullTotalVirtual         uint64
+	ullAvailVirtual         uint64
+	ullAvailExtendedVirtual uint64
+}
+
+var (
+	modkernel32              = syscall.NewLazyDLL("kernel32.dll")
+	procGlobalMemoryStatusEx = modkernel32.NewProc("GlobalMemoryStatusEx")
+)
+
+func globalMemoryStatusEx(memoryStatusEx *MemoryStatusEx) error {
+	ret, _, _ := procGlobalMemoryStatusEx.Call(uintptr(unsafe.Pointer(memoryStatusEx)))
+	if ret == 0 {
+		return syscall.GetLastError()
+	}
+	return nil
 }