1 /* Copyright (c) 2007-2023. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "src/mc/AddressSpace.hpp"
7 #include "src/mc/sosp/ChunkedData.hpp"
9 namespace simgrid::mc {
11 /** Take a per-page snapshot of a region
13 * @param addr The start of the region (must be at the beginning of a page)
14 * @param page_count Number of pages of the region
15 * @return Snapshot page numbers of this new snapshot
17 ChunkedData::ChunkedData(PageStore& store, const AddressSpace& as, RemotePtr<void> addr, std::size_t page_count)
20 this->pagenos_.resize(page_count);
21 std::vector<char> buffer(xbt_pagesize);
23 for (size_t i = 0; i != page_count; ++i) {
24 RemotePtr<void> page = remote((void*)simgrid::mc::mmu::join(i, addr.address()));
25 xbt_assert(simgrid::mc::mmu::split(page.address()).second == 0, "Not at the beginning of a page");
27 /* Adding another copy (and a syscall) will probably slow things a lot.
28 TODO, optimize this somehow (at least by grouping the syscalls)
30 - reduce the number of syscalls
31 - let the application snapshot itself
32 - move the segments in shared memory (this will break `fork` however)
35 as.read_bytes(buffer.data(), xbt_pagesize, page);
37 pagenos_[i] = store_->store_page(buffer.data());
41 } // namespace simgrid::mc