1 /* Copyright (c) 2007-2019. 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. */
11 #include "xbt/asserts.h"
14 #include "src/mc/AddressSpace.hpp"
15 #include "src/mc/sosp/ChunkedData.hpp"
16 #include "src/mc/sosp/PageStore.hpp"
21 /** Take a per-page snapshot of a region
23 * @param addr The start of the region (must be at the beginning of a page)
24 * @param page_count Number of pages of the region
25 * @return Snapshot page numbers of this new snapshot
27 ChunkedData::ChunkedData(PageStore& store, AddressSpace& as, RemotePtr<void> addr, std::size_t page_count)
30 this->pagenos_.resize(page_count);
31 std::vector<char> buffer(xbt_pagesize);
33 for (size_t i = 0; i != page_count; ++i) {
35 RemotePtr<void> page = remote((void*)simgrid::mc::mmu::join(i, addr.address()));
36 xbt_assert(simgrid::mc::mmu::split(page.address()).second == 0, "Not at the beginning of a page");
38 /* Adding another copy (and a syscall) will probably slow things a lot.
39 TODO, optimize this somehow (at least by grouping the syscalls)
41 - reduce the number of syscalls
42 - let the application snapshot itself
43 - move the segments in shared memory (this will break `fork` however)
46 as.read_bytes(buffer.data(), xbt_pagesize, page, simgrid::mc::ProcessIndexDisabled);
48 pagenos_[i] = store_->store_page(buffer.data());
53 } // namespace simgrid