libc/src/sys/wait/wait4Impl.h

   1 //===-- String to integer conversion utils ----------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC_SYS_WAIT_WAIT4IMPL_H
  10 #define LLVM_LIBC_SRC_SYS_WAIT_WAIT4IMPL_H
  11
  12 #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
  13 #include "src/__support/common.h"
  14 #include "src/__support/error_or.h"
  15 #include "src/errno/libc_errno.h"
  16
  17 #include <signal.h>
  18 #include <sys/syscall.h> // For syscall numbers.
  19 #include <sys/wait.h>
  20
  21 namespace LIBC_NAMESPACE {
  22 namespace internal {
  23
  24 // The implementation of wait here is very minimal. We will add more
  25 // functionality and standard compliance in future.
  26
  27 LIBC_INLINE ErrorOr<pid_t> wait4impl(pid_t pid, int *wait_status, int options,
  28                                      struct rusage *usage) {
  29 #if SYS_wait4
  30   pid = LIBC_NAMESPACE::syscall_impl<pid_t>(SYS_wait4, pid, wait_status,
  31                                             options, usage);
  32 #elif defined(SYS_waitid)
  33   int idtype = P_PID;
  34   if (pid == -1) {
  35     idtype = P_ALL;
  36   } else if (pid < -1) {
  37     idtype = P_PGID;
  38     pid *= -1;
  39   } else if (pid == 0) {
  40     idtype = P_PGID;
  41   }
  42
  43   options |= WEXITED;
  44
  45   siginfo_t info;
  46   pid = LIBC_NAMESPACE::syscall_impl<pid_t>(SYS_waitid, idtype, pid, &info,
  47                                             options, usage);
  48   if (pid >= 0)
  49     pid = info.si_pid;
  50
  51   if (wait_status) {
  52     switch (info.si_code) {
  53     case CLD_EXITED:
  54       *wait_status = W_EXITCODE(info.si_status, 0);
  55       break;
  56     case CLD_DUMPED:
  57       *wait_status = info.si_status | WCOREFLAG;
  58       break;
  59     case CLD_KILLED:
  60       *wait_status = info.si_status;
  61       break;
  62     case CLD_TRAPPED:
  63     case CLD_STOPPED:
  64       *wait_status = W_STOPCODE(info.si_status);
  65       break;
  66     case CLD_CONTINUED:
  67       *wait_status = __W_CONTINUED;
  68       break;
  69     default:
  70       *wait_status = 0;
  71       break;
  72     }
  73   }
  74 #else
  75 #error "wait4 and waitid syscalls not available."
  76 #endif
  77   if (pid < 0)
  78     return Error(-pid);
  79   return pid;
  80 }
  81
  82 } // namespace internal
  83 } // namespace LIBC_NAMESPACE
  84
  85 #endif // LLVM_LIBC_SRC_SYS_WAIT_WAIT4IMPL_H