dotcloud/docker

package platform // import "github.com/docker/docker/pkg/platform"

import (
    "fmt"
    "syscall"
    "unsafe"

    "golang.org/x/sys/windows"
)

var (
    modkernel32       = windows.NewLazySystemDLL("kernel32.dll")
    procGetSystemInfo = modkernel32.NewProc("GetSystemInfo")
)

// see https://learn.microsoft.com/en-gb/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info
type systeminfo struct {
    wProcessorArchitecture      uint16
    wReserved                   uint16
    dwPageSize                  uint32
    lpMinimumApplicationAddress uintptr
    lpMaximumApplicationAddress uintptr
    dwActiveProcessorMask       uintptr
    dwNumberOfProcessors        uint32
    dwProcessorType             uint32
    dwAllocationGranularity     uint32
    wProcessorLevel             uint16
    wProcessorRevision          uint16
}

// Windows processor architectures.
//
// see https://github.com/microsoft/go-winio/blob/v0.6.0/wim/wim.go#L48-L65
// see https://learn.microsoft.com/en-gb/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info
const (
    processorArchitecture64    = 9  // PROCESSOR_ARCHITECTURE_AMD64
    processorArchitectureIA64  = 6  // PROCESSOR_ARCHITECTURE_IA64
    processorArchitecture32    = 0  // PROCESSOR_ARCHITECTURE_INTEL
    processorArchitectureArm   = 5  // PROCESSOR_ARCHITECTURE_ARM
    processorArchitectureArm64 = 12 // PROCESSOR_ARCHITECTURE_ARM64
)

// runtimeArchitecture gets the name of the current architecture (x86, x86_64, …)
func runtimeArchitecture() (string, error) {
    // TODO(thaJeztah): rewrite this to use "GetNativeSystemInfo" instead.
    // See: https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsysteminfo
    // See: https://github.com/shirou/gopsutil/blob/v3.23.3/host/host_windows.go#L267-L297
    // > To retrieve accurate information for an application running on WOW64,
    // > call the GetNativeSystemInfo function.
    var sysinfo systeminfo
    _, _, _ = syscall.SyscallN(procGetSystemInfo.Addr(), uintptr(unsafe.Pointer(&sysinfo)))
    switch sysinfo.wProcessorArchitecture {
    case processorArchitecture64, processorArchitectureIA64:
        return "x86_64", nil
    case processorArchitecture32:
        return "i686", nil
    case processorArchitectureArm:
        return "arm", nil
    case processorArchitectureArm64:
        return "arm64", nil
    default:
        return "", fmt.Errorf("unknown processor architecture %+v", sysinfo.wProcessorArchitecture)
    }
}

// NumProcs returns the number of processors on the system
func NumProcs() uint32 {
    var sysinfo systeminfo
    _, _, _ = syscall.SyscallN(procGetSystemInfo.Addr(), uintptr(unsafe.Pointer(&sysinfo)))
    return sysinfo.dwNumberOfProcessors
}