/* Check multiple makecontext calls.

   Copyright (C) 2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdio.h>

#include <stdlib.h>

#include <ucontext.h>

static ucontext_t uctx_main, uctx_func1, uctx_func2;

const char *str1 = "\e[31mswapcontext(&uctx_func1, &uctx_main)\e[0m";

const char *str2 = "\e[34mswapcontext(&uctx_func2, &uctx_main)\e[0m";

const char *fmt1 = "\e[31m";

const char *fmt2 = "\e[34m";

#define handle_error(msg) \

  do { perror(msg); exit(EXIT_FAILURE); } while (0)

__attribute__((noinline, noclone))

static void

func4(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt)

{

  printf("      %sfunc4: %s\e[0m\n", fmt, str);

  if (swapcontext(uocp, ucp) == -1)

    handle_error("swapcontext");

  printf("      %sfunc4: returning\e[0m\n", fmt);

}

__attribute__((noinline, noclone))

static void

func3(ucontext_t *uocp, ucontext_t *ucp, const char *str, const char *fmt)

{

  printf("    %sfunc3: func4(uocp, ucp, str)\e[0m\n", fmt);

  func4(uocp, ucp, str, fmt);

  printf("    %sfunc3: returning\e[0m\n", fmt);

}

__attribute__((noinline, noclone))

static void

func1(void)

{

  while ( 1 )

    {

      printf("  \e[31mfunc1: func3(&uctx_func1, &uctx_main, str1)\e[0m\n");

      func3( &uctx_func1, &uctx_main, str1, fmt1);

    }

}

__attribute__((noinline, noclone))

static void

func2(void)

{

  while ( 1 )

    {

      printf("  \e[34mfunc2: func3(&uctx_func2, &uctx_main, str2)\e[0m\n");

      func3(&uctx_func2, &uctx_main, str2, fmt2);

    }

}

static int

do_test (void)

{

  char func1_stack[16384];

  char func2_stack[16384];

  int i;

  if (getcontext(&uctx_func1) == -1)

    handle_error("getcontext");

  uctx_func1.uc_stack.ss_sp = func1_stack;

  uctx_func1.uc_stack.ss_size = sizeof(func1_stack);

  uctx_func1.uc_link = &uctx_main;

  makecontext(&uctx_func1, func1, 0);

  if (getcontext(&uctx_func2) == -1)

    handle_error("getcontext");

  uctx_func2.uc_stack.ss_sp = func2_stack;

  uctx_func2.uc_stack.ss_size = sizeof(func2_stack);

  uctx_func2.uc_link = &uctx_func1;

  makecontext(&uctx_func2, func2, 0);

  for ( i = 0; i < 4; i++ )

    {

      if (swapcontext(&uctx_main, &uctx_func1) == -1)

	handle_error("swapcontext");

      printf("        \e[35mmain: swapcontext(&uctx_main, &uctx_func2)\n\e[0m");

      if (swapcontext(&uctx_main, &uctx_func2) == -1)

	handle_error("swapcontext");

      printf("        \e[35mmain: swapcontext(&uctx_main, &uctx_func1)\n\e[0m");

    }

  printf("main: exiting\n");

  exit(EXIT_SUCCESS);

}

#include <support/test-driver.c>