package unix

import (
	"sync/atomic"
	"syscall"
	"unsafe"
)

var getrandomUnsupported atomic.Bool

// GetRandomFlag is a flag supported by the getrandom system call.
type GetRandomFlag uintptr

// GetRandom calls the getrandom system call.
func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
	if len(p) == 0 {
		return 0, nil
	}
	if getrandomUnsupported.Load() {
		return 0, syscall.ENOSYS
	}

// reading from /dev/urandom in rand_unix.go. unix.GetRandom caches the ENOSYS
// result so we only suffer the syscall overhead once in this case.
// If the kernel supports the getrandom() syscall, unix.GetRandom will block
// until the kernel has sufficient randomness (as we don't use GRND_NONBLOCK).
// In this case, unix.GetRandom will not return an error.
func getRandom(p []byte) error {
	n, err := unix.GetRandom(p, 0)
	if err != nil {
		return err
	}

	// GRND_RANDOM means use the /dev/random pool instead of /dev/urandom.
	GRND_RANDOM GetRandomFlag = 0x0002
)

// GetRandom calls the getrandom system call.
func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
	if len(p) == 0 {
		return 0, nil
	}
	if getrandomUnsupported.Load() {
		return 0, syscall.ENOSYS
	}
	r1, _, errno := syscall6(uintptr(unsafe.Pointer(&procGetrandom)),
		3,

const maxGetRandomRead = 64 << 10

var batchedGetRandom func([]byte) error

func init() {
	Reader = &reader{}
	batchedGetRandom = batched(getRandom, maxGetRandomRead)
}

var jsCrypto = js.Global().Get("crypto")
var uint8Array = js.Global().Get("Uint8Array")

// reader implements a pseudorandom generator
// using JavaScript crypto.getRandomValues method.

### OpenBSD {#openbsd}

<!-- go.dev/issue/55999, CL 518629, CL 518630 -->
Go 1.23 adds experimental support for OpenBSD on 64-bit RISC-V (`GOOS=openbsd`, `GOARCH=riscv64`).

### ARM64 {#arm64}

// random number generator.
package rand

import "io"

// Reader is a global, shared instance of a cryptographically
// secure random number generator.
//
//   - On Linux, FreeBSD, Dragonfly, and Solaris, Reader uses getrandom(2)
//     if available, and /dev/urandom otherwise.
//   - On macOS and iOS, Reader uses arc4random_buf(3).
//   - On OpenBSD and NetBSD, Reader uses getentropy(2).

	MOVD $·Futimesat(SB), R8
	MOVD R8, ret+0(FP)
	RET

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

TEXT ·get_GetrandomAddr(SB), NOSPLIT|NOFRAME, $0-8
	MOVD $·Getrandom(SB), R8
	MOVD R8, ret+0(FP)
	RET

// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT

TEXT ·get_InotifyInitAddr(SB), NOSPLIT|NOFRAME, $0-8
	MOVD $·InotifyInit(SB), R8
	MOVD R8, ret+0(FP)

    public BaseConfiguration ( boolean initDefaults ) throws CIFSException {
        if ( initDefaults ) {
            this.initDefaults();
        }
    }


    @Override
    public SecureRandom getRandom () {
        return this.random;
    }


    @Override
    public String getNetbiosHostname () {
        return this.netbiosHostname;
    }


    @Override

 * 
 * @author mbechler
 *
 */
public interface Configuration {

    /**
     * 
     * @return random source to use
     */
    SecureRandom getRandom ();


    /**
     * 
     * 
     * Property <tt>jcifs.smb.client.dfs.ttl</tt> (int, default 300)
     * 
     * @return title to live, in seconds, for DFS cache entries
     */
    long getDfsTtl ();

	SYS_LWP_GETNAME            = 549 // { int lwp_getname(lwpid_t tid, char *name, size_t len); }
	SYS_GETRANDOM              = 550 // { ssize_t getrandom(void *buf, size_t len, unsigned flags); }
	SYS___REALPATH             = 551 // { ssize_t __realpath(const char *path, char *buf, size_t len); }