}
	defer out.Close()

	// Try fallocate first.
	for {
		err = out.fallocate(1 << 10)
		if errors.Is(err, errors.ErrUnsupported) || err == errNoFallocate { // The underlying file system may not support fallocate
			t.Skip("fallocate is not supported")
		}
		if err == syscall.EINTR {
			continue // try again
		}
		if err != nil {
			t.Fatalf("fallocate failed: %v", err)
		}
		break
	}

func (out *OutBuf) Mmap(filesize uint64) (err error) {
	oldlen := len(out.buf)
	if oldlen != 0 {
		out.munmap()
	}

	for {
		if err = out.fallocate(filesize); err != syscall.EINTR {
			break
		}
	}
	if err != nil {
		// Some file systems do not support fallocate. We ignore that error as linking
		// can still take place, but you might SIGBUS when you write to the mmapped
		// area.

// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build !darwin && !(freebsd && go1.21) && !linux

package ld

func (out *OutBuf) fallocate(size uint64) error {
	return errNoFallocate

// license that can be found in the LICENSE file.

//go:build freebsd && go1.21

package ld

import (
	"internal/syscall/unix"
	"syscall"
)

func (out *OutBuf) fallocate(size uint64) error {
	err := unix.PosixFallocate(int(out.f.Fd()), 0, int64(size))
	// ZFS on FreeBSD does not support posix_fallocate and returns EINVAL in that case.
	if err == syscall.EINVAL {
		return errNoFallocate
	}

func (out *OutBuf) fallocate(size uint64) error {
	stat, err := out.f.Stat()
	if err != nil {
		return err
	}
	// F_PEOFPOSMODE allocates from the end of the file, so we want the size difference.
	// Apparently, it uses the end of the allocation, instead of the logical end of the
	// file.
	cursize := uint64(stat.Sys().(*syscall.Stat_t).Blocks * 512) // allocated size
	if size <= cursize {
		return nil
	}

		return nil
	}

	return errors
}

// Allocates a port, and record it for future rollback
func (op *PortAllocationOperation) Allocate(port int) error {
	if op.dryRun {
		if op.pa.Has(port) {
			return ErrAllocated
		}
		for _, a := range op.allocated {
			if port == a {
				return ErrAllocated
			}
		}
		op.allocated = append(op.allocated, port)
		return nil
	}

		}

		// Add the existing block to the full list.
		block.next = a.full
		a.full = block
	}

	// Allocate a new block.
	block = (*traceRegionAllocBlock)(sysAlloc(unsafe.Sizeof(traceRegionAllocBlock{}), &memstats.other_sys))
	if block == nil {
		throw("traceRegion: out of memory")
	}

	// Allocate space for our current request, so we always make
	// progress.
	block.off.Store(n)

		// include valid port range in error
		validPorts := r.portRange.String()
		return &ErrNotInRange{validPorts}
	}

	allocated, err := r.alloc.Allocate(offset)
	if err != nil {
		// update metrics
		r.metrics.incrementAllocationErrors("static")
		return err
	}
	if !allocated {
		// update metrics
		r.metrics.incrementAllocationErrors("static")
		return ErrAllocated
	}

	// update metrics

			rand:   rand.New(rand.NewSource(time.Now().UnixNano())),
			offset: offset,
		},
		allocated: big.NewInt(0),
		count:     0,
		max:       max,
		rangeSpec: rangeSpec,
	}

	return &a
}

// Allocate attempts to reserve the provided item.
// Returns true if it was allocated, false if it was already in use
func (r *AllocationBitmap) Allocate(offset int) (bool, error) {
	r.lock.Lock()
	defer r.lock.Unlock()

		t.Fatalf("unexpected error: %v", err)
	}

	// Allocate a port inside the valid port range
	if err := storage.Allocate(30100); err != nil {
		t.Fatal(err)
	}

	// Try to allocate the same port in the local bitmap
	// The local bitmap stores the offset of the port
	// offset = port - base (30100 - 30000 = 100)
	ok, err := backing.Allocate(100)
	if err != nil {
		t.Fatal(err)
	}