fusl/src/ipc/semctl.c

#include <sys/sem.h>
#include <stdarg.h>
#include "syscall.h"
#include "ipc.h"

union semun {
  int val;
  struct semid_ds* buf;
  unsigned short* array;
};

int semctl(int id, int num, int cmd, ...) {
  union semun arg = {0};
  va_list ap;
  switch (cmd) {
    case SETVAL:
    case GETALL:
    case SETALL:
    case IPC_STAT:
    case IPC_SET:
    case IPC_INFO:
    case SEM_INFO:
    case SEM_STAT:
      va_start(ap, cmd);
      arg = va_arg(ap, union semun);
      va_end(ap);
  }
#ifdef SYS_semctl
  return syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
#else
  return syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);
#endif
}