text: /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
  │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
  ╞══════════════════════════════════════════════════════════════════════════════╡
  │ Copyright 2020 Justine Alexandra Roberts Tunney                              │
  │                                                                              │
  │ Permission to use, copy, modify, and/or distribute this software for         │
  │ any purpose with or without fee is hereby granted, provided that the         │
  │ above copyright notice and this permission notice appear in all copies.      │
  │                                                                              │
  │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
  │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
  │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
  │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
  │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
  │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
  │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
  │ PERFORMANCE OF THIS SOFTWARE.                                                │
  ╚─────────────────────────────────────────────────────────────────────────────*/
  #include "libc/errno.h"
  #include "libc/runtime/stack.h"
  #include "libc/thread/thread.h"
  
  #define MIN_STACKSIZE (8 * PAGESIZE)  // includes guard, rounds up to FRAMESIZE
  #define MIN_GUARDSIZE PAGESIZE
  
  // CTOR/DTOR
  int cthread_attr_init(cthread_attr_t* attr) {
    attr->stacksize = GetStackSize();
    attr->guardsize = PAGESIZE;
    attr->mode = CTHREAD_CREATE_JOINABLE;
    return 0;
  }
  int cthread_attr_destroy(cthread_attr_t* attr) {
    (void)attr;
    return 0;
  }
  
  // stacksize
  int cthread_attr_setstacksize(cthread_attr_t* attr, size_t size) {
    if (size & (PAGESIZE - 1)) return EINVAL;
    if (size < MIN_STACKSIZE) return EINVAL;
    attr->stacksize = size;
    return 0;
  }
  size_t cthread_attr_getstacksize(const cthread_attr_t* attr) {
    return attr->stacksize;
  }
  
  // guardsize
  int cthread_attr_setguardsize(cthread_attr_t* attr, size_t size) {
    if (size & (PAGESIZE - 1)) return EINVAL;
    if (size < MIN_GUARDSIZE) return EINVAL;
    attr->guardsize = size;
    return 0;
  }
  size_t cthread_attr_getguardsize(const cthread_attr_t* attr) {
    return attr->guardsize;
  }
  
  // detachstate
  int cthread_attr_setdetachstate(cthread_attr_t* attr, int mode) {
    if (mode & ~(CTHREAD_CREATE_JOINABLE | CTHREAD_CREATE_DETACHED))
      return EINVAL;
    attr->mode = mode;
    return 0;
  }
  int cthread_attr_getdetachstate(const cthread_attr_t* attr) {
    return attr->mode;
  }
  