obstack/obstack.cpp at master · cleeus/obstack · GitHub

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#include<limits>
#include<cstdlib>

#include<boost/random/mersenne_twister.hpp>
#include<boost/random/uniform_int.hpp>


#include"obstack.hpp"

namespaceboost {
namespacearena {
namespacearena_detail {

voidfree_marker_dtor(void*) {
}
voidarray_of_primitives_dtor(void*) {
}

staticsize_tseed_from_heap_memory() {
size_tconst len = 64*1024 / sizeof(size_t);
size_t * const mem = newsize_t[len];
size_t seed = reinterpret_cast<size_t>(mem);

for(size_t i=0; i<len; i++) {
 seed ^= mem[i];
	}

delete[] mem;
return seed;
}

staticsize_tmake_strong_seed() {
size_t seed = 0;
	seed ^= seed_from_heap_memory();
//TODO add more seed sources
return seed;
}

staticsize_tinit_cookie() {
	boost::mt19937 gen;
staticsize_t seed = 0;
if(!seed) {
 seed = make_strong_seed();
	} else {
 seed++;
	}

	gen.seed(seed);
	boost::uniform_int<size_t> dist(0, std::numeric_limits<size_t>::max());

size_tconst cookie = dist(gen);

return cookie;
}

staticint invalid_addr_reference;
size_tconst ptr_sec::_checksum_cookie = init_cookie();
void * const ptr_sec::_xor_cookie = reinterpret_cast<void*>(init_cookie());
void * const ptr_sec::_invalid_addr = &invalid_addr_reference;
//warning: initialization order is important here
dtor_fptr const free_marker_dtor_xor = ptr_sec::xor_ptr(&free_marker_dtor);
dtor_fptr const array_of_primitives_dtor_xor = ptr_sec::xor_ptr(&array_of_primitives_dtor);


} //namespace arena_detail
} //namespace arena
} //namespace boost