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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build aix darwin dragonfly freebsd hurd linux netbsd openbsd solaris
package syscall
import (
"internal/race"
"runtime"
"sync"
"unsafe"
)
var (
Stdin = 0
Stdout = 1
Stderr = 2
)
const (
darwin64Bit = runtime.GOOS == "darwin" && sizeofPtr == 8
netbsd32Bit = runtime.GOOS == "netbsd" && sizeofPtr == 4
)
// clen returns the index of the first NULL byte in n or len(n) if n contains no NULL byte.
func clen(n []byte) int {
for i := 0; i < len(n); i++ {
if n[i] == 0 {
return i
}
}
return len(n)
}
// Mmap manager, for use by operating system-specific implementations.
// Gccgo only has one implementation but we do this to correspond to gc.
type mmapper struct {
sync.Mutex
active map[*byte][]byte // active mappings; key is last byte in mapping
mmap func(addr, length uintptr, prot, flags, fd int, offset int64) (uintptr, error)
munmap func(addr uintptr, length uintptr) error
}
func (m *mmapper) Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
if length <= 0 {
return nil, EINVAL
}
// Map the requested memory.
addr, errno := m.mmap(0, uintptr(length), prot, flags, fd, offset)
if errno != nil {
return nil, errno
}
// Slice memory layout
var sl = struct {
addr uintptr
len int
cap int
}{addr, length, length}
// Use unsafe to turn sl into a []byte.
b := *(*[]byte)(unsafe.Pointer(&sl))
// Register mapping in m and return it.
p := &b[cap(b)-1]
m.Lock()
defer m.Unlock()
m.active[p] = b
return b, nil
}
func (m *mmapper) Munmap(data []byte) (err error) {
if len(data) == 0 || len(data) != cap(data) {
return EINVAL
}
// Find the base of the mapping.
p := &data[cap(data)-1]
m.Lock()
defer m.Unlock()
b := m.active[p]
if b == nil || &b[0] != &data[0] {
return EINVAL
}
// Unmap the memory and update m.
if errno := m.munmap(uintptr(unsafe.Pointer(&b[0])), uintptr(len(b))); errno != nil {
return errno
}
delete(m.active, p)
return nil
}
var mapper = &mmapper{
active: make(map[*byte][]byte),
mmap: mmap,
munmap: munmap,
}
func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, err error) {
return mapper.Mmap(fd, offset, length, prot, flags)
}
func Munmap(b []byte) (err error) {
return mapper.Munmap(b)
}
// Do the interface allocations only once for common
// Errno values.
var (
errEAGAIN error = EAGAIN
errEINVAL error = EINVAL
errENOENT error = ENOENT
)
// errnoErr returns common boxed Errno values, to prevent
// allocations at runtime.
func errnoErr(e Errno) error {
switch e {
case 0:
return nil
case EAGAIN:
return errEAGAIN
case EINVAL:
return errEINVAL
case ENOENT:
return errENOENT
}
return e
}
// A Signal is a number describing a process signal.
// It implements the os.Signal interface.
type Signal int
func (s Signal) Signal() {}
func Signame(s Signal) string
func (s Signal) String() string {
return Signame(s)
}
func Read(fd int, p []byte) (n int, err error) {
n, err = read(fd, p)
if race.Enabled {
if n > 0 {
race.WriteRange(unsafe.Pointer(&p[0]), n)
}
if err == nil {
race.Acquire(unsafe.Pointer(&ioSync))
}
}
if msanenabled && n > 0 {
msanWrite(unsafe.Pointer(&p[0]), n)
}
return
}
func Write(fd int, p []byte) (n int, err error) {
if race.Enabled {
race.ReleaseMerge(unsafe.Pointer(&ioSync))
}
if faketime && (fd == 1 || fd == 2) {
n = faketimeWrite(fd, p)
if n < 0 {
n, err = 0, errnoErr(Errno(-n))
}
} else {
n, err = write(fd, p)
}
if race.Enabled && n > 0 {
race.ReadRange(unsafe.Pointer(&p[0]), n)
}
if msanenabled && n > 0 {
msanRead(unsafe.Pointer(&p[0]), n)
}
return
}
var ioSync int64
|
