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update methods

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hslam 2020-12-01 18:59:37 +08:00
parent 1427d2822f
commit a070144a78
1 changed files with 27 additions and 5 deletions
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32
sem_unix.go
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@ -109,16 +109,33 @@ func op(semid int, semnum uint16, semop, semflg int16) (bool, error) {
}
var sops [1]Sembuf
sops[0] = Sembuf{SemNum: semnum, SemOp: semop, SemFlg: semflg}
return Op(semid, sops[:])
return Operate(semid, sops[:])
}
// Op calls the semop system call.
// Flags recognized in SemFlg are IPC_NOWAIT and SEM_UNDO.
//
// semop() performs operations on selected semaphores in the set indi‐
// cated by semid. Each of the nsops elements in the array pointed to
// by sops is a structure that specifies an operation to be performed on
// a single semaphore. The elements of this structure are of type
// struct sembuf, containing the following members:
//
// unsigned short sem_num; /* semaphore number */
// short sem_op; /* semaphore operation */
// short sem_flg; /* operation flags */
//
// Flags recognized in sem_flg are IPC_NOWAIT and SEM_UNDO.
// If an operation specifies SEM_UNDO, it will be automatically undone when the
// process terminates.
func Op(semid int, sops []Sembuf) (bool, error) {
nsops := len(sops)
r1, _, err := syscall.Syscall(syscall.SYS_SEMOP, uintptr(semid), uintptr(unsafe.Pointer(&sops[0])), uintptr(nsops))
//
// The set of operations contained in sops is performed in array order,
// and atomically, that is, the operations are performed either as a
// complete unit, or not at all. The behavior of the system call if not
// all operations can be performed immediately depends on the presence
// of the IPC_NOWAIT flag in the individual sem_flg fields, as noted be‐
// low.
func Op(semid int, sops uintptr, nsops int) (bool, error) {
r1, _, err := syscall.Syscall(syscall.SYS_SEMOP, uintptr(semid), sops, uintptr(nsops))
var ok = true
if int(r1) < 0 {
ok = false
@ -129,6 +146,11 @@ func Op(semid int, sops []Sembuf) (bool, error) {
return ok, nil
}
// Operate calls the semop system call.
func Operate(semid int, sops []Sembuf) (bool, error) {
return Op(semid, uintptr(unsafe.Pointer(&sops[0])), len(sops))
}
// Remove removes the semaphore set with the given id.
func Remove(semid int) error {
r1, _, errno := syscall.Syscall(syscall.SYS_SEMCTL, uintptr(semid), IPC_RMID, 0)