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/* This file is part of Jellyfish.
This work is dual-licensed under 3-Clause BSD License or GPL 3.0.
You can choose between one of them if you use this work.
`SPDX-License-Identifier: BSD-3-Clause OR GPL-3.0`
*/
#include <config.h>
#include <assert.h>
#include <jellyfish/allocators_mmap.hpp>
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS MAP_ANON
#endif
#ifdef HAVE_VALGRIND
#include <valgrind.h>
// TODO: this should really come from the valgrind switch
// --redzone-size. Don't know how to get access to that yet!
static size_t redzone_size = 128;
#endif
void *allocators::mmap::realloc(size_t new_size) {
void *new_ptr = MAP_FAILED;
const size_t asize = new_size
#ifdef HAVE_VALGRIND
+ 2 * redzone_size
#endif
;
if(ptr_ == MAP_FAILED) {
new_ptr = ::mmap(NULL, asize, PROT_WRITE|PROT_READ,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
}
// mremap is Linux specific
// TODO: We must do something if it is not supported
#ifdef MREMAP_MAYMOVE
else {
new_ptr = ::mremap(ptr_, size_, new_size, MREMAP_MAYMOVE);
}
#endif
if(new_ptr == MAP_FAILED)
return NULL;
#ifdef HAVE_VALGRIND
new_ptr = (char*)new_ptr + redzone_size;
if(ptr_ == MAP_FAILED)
VALGRIND_MALLOCLIKE_BLOCK(new_ptr, new_size, redzone_size, 1);
// TODO: resize not yet supported
#endif
size_ = new_size;
ptr_ = new_ptr;
fast_zero();
return ptr_;
}
size_t allocators::mmap::round_to_page(size_t _size) {
static const long pg_size = sysconf(_SC_PAGESIZE);
return (_size / pg_size + (_size % pg_size != 0)) * pg_size;
}
void allocators::mmap::fast_zero() {
tinfo info[nb_threads];
size_t pgsize = round_to_page(1);
size_t nb_pages = size_ / pgsize + (size_ % pgsize != 0);
int total_threads = 0;
for(size_t i = 0; i < (size_t)nb_threads; ++i, ++total_threads) {
info[i].start = (char *)ptr_ + pgsize * ((i * nb_pages) / nb_threads);
info[i].end = (char *)ptr_ + std::min(pgsize * (((i + 1) * nb_pages) / nb_threads), size_);
info[i].pgsize = pgsize;
if(pthread_create(&info[i].thid, NULL, _fast_zero, &info[i]))
break;
}
for(int i = 0; i < total_threads; i++)
pthread_join(info[i].thid, NULL);
}
void * allocators::mmap::_fast_zero(void *_info) {
tinfo *info = (tinfo *)_info;
for(char *cptr = info->start; cptr < info->end; cptr += info->pgsize) {
*cptr = 0;
}
return NULL;
}
void allocators::mmap::free() {
if(ptr_ == MAP_FAILED)
return;
#ifdef HAVE_VALGRIND
VALGRIND_FREELIKE_BLOCK(ptr_, redzone_size);
ptr_ = (char*)ptr_ - redzone_size;
size_ += 2 * redzone_size;
#endif
assert(::munmap(ptr_, size_) == 0);
ptr_ = MAP_FAILED;
size_ = 0;
}
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