ceph/src/boost/libs/coroutine/example/symmetric/segmented_stack.cpp

   1
   2 //          Copyright Oliver Kowalke 2009.
   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 <iostream>
   8
   9 #include <boost/assert.hpp>
  10 #include <boost/config.hpp>
  11 #include <boost/coroutine/all.hpp>
  12 #include <boost/thread.hpp>
  13
  14 int count = 384;
  15
  16 #ifdef BOOST_MSVC //MS VisualStudio
  17 __declspec(noinline) void access( char *buf);
  18 #else // GCC
  19 void access( char *buf) __attribute__ ((noinline));
  20 #endif
  21 void access( char *buf)
  22 {
  23   buf[0] = '\0';
  24 }
  25
  26 void bar( int i)
  27 {
  28     char buf[4 * 1024];
  29
  30     if ( i > 0)
  31     {
  32         access( buf);
  33         std::cout << i << ". iteration" << std::endl;
  34         bar( i - 1);
  35     }
  36 }
  37
  38 void foo( boost::coroutines::symmetric_coroutine< void >::yield_type &)
  39 {
  40     bar( count);
  41 }
  42
  43 void thread_fn()
  44 {
  45     {
  46         boost::coroutines::symmetric_coroutine< void >::call_type coro( foo);
  47         coro();
  48     }
  49 }
  50
  51 int main( int argc, char * argv[])
  52 {
  53 #if defined(BOOST_USE_SEGMENTED_STACKS)
  54     std::cout << "using segmented stacks: allocates " << count << " * 4kB == " << 4 * count << "kB on stack, ";
  55     std::cout << "initial stack size = " << boost::coroutines::stack_allocator::traits_type::default_size() / 1024 << "kB" << std::endl;
  56     std::cout << "application should not fail" << std::endl;
  57 #else
  58     std::cout << "using standard stacks: allocates " << count << " * 4kB == " << 4 * count << "kB on stack, ";
  59     std::cout << "initial stack size = " << boost::coroutines::stack_allocator::traits_type::default_size() / 1024 << "kB" << std::endl;
  60     std::cout << "application might fail" << std::endl;
  61 #endif
  62
  63     boost::thread( thread_fn).join();
  64
  65     return 0;
  66 }