ceph/src/boost/libs/context/example/fiber/segmented.cpp

   1
   2 //          Copyright Oliver Kowalke 2014.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <cstdlib>
   8 #include <iostream>
   9 #include <memory>
  10
  11 #include <boost/context/fiber.hpp>
  12
  13 namespace ctx = boost::context;
  14
  15 #ifdef BOOST_MSVC //MS VisualStudio
  16 __declspec(noinline) void access( char *buf);
  17 #else // GCC
  18 void access( char *buf) __attribute__ ((noinline));
  19 #endif
  20 void access( char *buf) {
  21   buf[0] = '\0';
  22 }
  23
  24 void bar( int i) {
  25     char buf[4 * 1024];
  26     if ( i > 0) {
  27         access( buf);
  28         std::cout << i << ". iteration" << std::endl;
  29         bar( i - 1);
  30     }
  31 }
  32
  33 int main() {
  34     int count = 100*1024;
  35 #if defined(BOOST_USE_SEGMENTED_STACKS)
  36     std::cout << "using segmented_stack stacks: allocates " << count << " * 4kB == " << 4 * count << "kB on stack, ";
  37     std::cout << "initial stack size = " << ctx::segmented_stack::traits_type::default_size() / 1024 << "kB" << std::endl;
  38     std::cout << "application should not fail" << std::endl;
  39 #else
  40     std::cout << "using standard stacks: allocates " << count << " * 4kB == " << 4 * count << "kB on stack, ";
  41     std::cout << "initial stack size = " << ctx::fixedsize_stack::traits_type::default_size() / 1024 << "kB" << std::endl;
  42     std::cout << "application might fail" << std::endl;
  43 #endif
  44     ctx::fiber{
  45         [count](ctx::fiber && f){
  46             bar( count);
  47             return std::move( f);
  48         }}.resume();
  49     std::cout << "main: done" << std::endl;
  50     return EXIT_SUCCESS;
  51 }