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glibc  2.9
Functions
pthread_kill.c File Reference
#include <errno.h>
#include <signal.h>
#include <pthreadP.h>
#include <tls.h>
#include <sysdep.h>
#include <kernel-features.h>

Go to the source code of this file.

Functions

int __pthread_kill (pthread_t threadid, int signo)

Function Documentation

int __pthread_kill ( pthread_t  threadid,
int  signo 
)

Definition at line 29 of file pthread_kill.c.

{
  struct pthread *pd = (struct pthread *) threadid;

  /* Make sure the descriptor is valid.  */
  if (DEBUGGING_P && INVALID_TD_P (pd))
    /* Not a valid thread handle.  */
    return ESRCH;

  /* Force load of pd->tid into local variable or register.  Otherwise
     if a thread exits between ESRCH test and tgkill, we might return
     EINVAL, because pd->tid would be cleared by the kernel.  */
  pid_t tid = atomic_forced_read (pd->tid);
  if (__builtin_expect (tid <= 0, 0))
    /* Not a valid thread handle.  */
    return ESRCH;

  /* Disallow sending the signal we use for cancellation, timers, for
     for the setxid implementation.  */
  if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
    return EINVAL;

  /* We have a special syscall to do the work.  */
  INTERNAL_SYSCALL_DECL (err);

  /* One comment: The PID field in the TCB can temporarily be changed
     (in fork).  But this must not affect this code here.  Since this
     function would have to be called while the thread is executing
     fork, it would have to happen in a signal handler.  But this is
     no allowed, pthread_kill is not guaranteed to be async-safe.  */
  int val;
#if __ASSUME_TGKILL
  val = INTERNAL_SYSCALL (tgkill, err, 3, THREAD_GETMEM (THREAD_SELF, pid),
                       tid, signo);
#else
# ifdef __NR_tgkill
  val = INTERNAL_SYSCALL (tgkill, err, 3, THREAD_GETMEM (THREAD_SELF, pid),
                       tid, signo);
  if (INTERNAL_SYSCALL_ERROR_P (val, err)
      && INTERNAL_SYSCALL_ERRNO (val, err) == ENOSYS)
# endif
    val = INTERNAL_SYSCALL (tkill, err, 2, tid, signo);
#endif

  return (INTERNAL_SYSCALL_ERROR_P (val, err)
         ? INTERNAL_SYSCALL_ERRNO (val, err) : 0);
}

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