pthread_cancel —
    cancel execution of a thread
POSIX Threads Library (libpthread,
    -lpthread)
#include
    <pthread.h>
int
  
  pthread_cancel(pthread_t
    thread);
The
    pthread_cancel()
    function requests that thread be canceled. The target
    thread's cancelability state and type determines when the cancellation takes
    effect. When the cancellation is acted on, the cancellation cleanup handlers
    for thread are called. When the last cancellation
    cleanup handler returns, the thread-specific data destructor functions will
    be called for thread. When the last destructor
    function returns, thread will be terminated.
The cancellation processing in the target
    thread runs asynchronously with respect to the calling thread returning from
    pthread_cancel().
A status of PTHREAD_CANCELED is made
    available to any threads joining with the target. The symbolic constant
    PTHREAD_CANCELED expands to a constant expression of
    type (void *), whose value matches no pointer to an
    object in memory nor the value NULL.
If successful, the pthread_cancel()
    functions will return zero. Otherwise an error number will be returned to
    indicate the error.
The pthread_cancel() function will fail
    if:
  - [ESRCH]
- No thread could be found corresponding to that specified by the given
      thread ID.
The pthread_cancel() function conforms to
    ISO/IEC 9945-1:1996 (“POSIX.1”).
This manual page was written by David
    Leonard
    <d@openbsd.org> for the
    OpenBSD implementation of
    pthread_cancel().