1 /* Copyright (c) 2014-2018. 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"
12 #include "xbt/sysdep.h"
14 #include "src/internal_config.h"
15 #include "src/smpi/include/private.hpp"
17 #include "src/mc/mc_mmu.hpp"
18 #include "src/mc/mc_private.hpp"
19 #include "src/mc/sosp/PageStore.hpp"
20 #include "src/mc/sosp/mc_snapshot.hpp"
22 /** @brief Find the snapshoted region from a pointer
25 * @param snapshot Snapshot
26 * @param Snapshot region in the snapshot this pointer belongs to
27 * (or nullptr if it does not belong to any snapshot region)
29 mc_mem_region_t mc_get_snapshot_region(const void* addr, const simgrid::mc::Snapshot* snapshot, int process_index)
31 size_t n = snapshot->snapshot_regions.size();
32 for (size_t i = 0; i != n; ++i) {
33 mc_mem_region_t region = snapshot->snapshot_regions[i].get();
34 if (not(region && region->contain(simgrid::mc::remote(addr))))
37 if (region->storage_type() == simgrid::mc::StorageType::Privatized) {
39 // Use the current process index of the snapshot:
40 if (process_index == simgrid::mc::ProcessIndexDisabled)
41 process_index = snapshot->privatization_index;
42 if (process_index < 0)
43 xbt_die("Missing process index");
44 if (process_index >= (int)region->privatized_data().size())
45 xbt_die("Invalid process index");
46 simgrid::mc::RegionSnapshot& priv_region = region->privatized_data()[process_index];
47 xbt_assert(priv_region.contain(simgrid::mc::remote(addr)));
50 xbt_die("Privatized region in a non SMPI build (this should not happen)");
60 /** @brief Read memory from a snapshot region broken across fragmented pages
62 * @param addr Process (non-snapshot) address of the data
63 * @param region Snapshot memory region where the data is located
64 * @param target Buffer to store the value
65 * @param size Size of the data to read in bytes
66 * @return Pointer where the data is located (target buffer of original location)
68 const void* MC_region_read_fragmented(mc_mem_region_t region, void* target, const void* addr, size_t size)
70 // Last byte of the memory area:
71 void* end = (char*)addr + size - 1;
73 // TODO, we assume the chunks are aligned to natural chunk boundaries.
74 // We should remove this assumption.
76 // Page of the last byte of the memory area:
77 size_t page_end = simgrid::mc::mmu::split((std::uintptr_t)end).first;
82 xbt_die("Missing destination buffer for fragmented memory access");
85 while (simgrid::mc::mmu::split((std::uintptr_t)addr).first != page_end) {
86 void* snapshot_addr = mc_translate_address_region_chunked((uintptr_t)addr, region);
87 void* next_page = (void*)simgrid::mc::mmu::join(simgrid::mc::mmu::split((std::uintptr_t)addr).first + 1, 0);
88 size_t readable = (char*)next_page - (char*)addr;
89 memcpy(dest, snapshot_addr, readable);
90 addr = (char*)addr + readable;
91 dest = (char*)dest + readable;
96 void* snapshot_addr = mc_translate_address_region_chunked((uintptr_t)addr, region);
97 memcpy(dest, snapshot_addr, size);
102 /** Compare memory between snapshots (with known regions)
104 * @param addr1 Address in the first snapshot
105 * @param snapshot2 Region of the address in the first snapshot
106 * @param addr2 Address in the second snapshot
107 * @param snapshot2 Region of the address in the second snapshot
108 * @return same as memcmp
110 int MC_snapshot_region_memcmp(const void* addr1, mc_mem_region_t region1, const void* addr2, mc_mem_region_t region2,
113 // Using alloca() for large allocations may trigger stack overflow:
114 // use malloc if the buffer is too big.
115 bool stack_alloc = size < 64;
116 void* buffer1a = nullptr;
117 void* buffer2a = nullptr;
118 if (region1 != nullptr && region1->storage_type() != simgrid::mc::StorageType::Flat)
119 buffer1a = stack_alloc ? alloca(size) : ::operator new(size);
120 if (region2 != nullptr && region2->storage_type() != simgrid::mc::StorageType::Flat)
121 buffer2a = stack_alloc ? alloca(size) : ::operator new(size);
122 const void* buffer1 = MC_region_read(region1, buffer1a, addr1, size);
123 const void* buffer2 = MC_region_read(region2, buffer2a, addr2, size);
125 if (buffer1 == buffer2)
128 res = memcmp(buffer1, buffer2, size);
129 if (not stack_alloc) {
130 ::operator delete(buffer1a);
131 ::operator delete(buffer2a);
139 Snapshot::Snapshot(RemoteClient* process, int _num_state)
140 : AddressSpace(process)
141 , num_state(_num_state)
143 , enabled_processes()
144 , privatization_index(0)
149 const void* Snapshot::read_bytes(void* buffer, std::size_t size, RemotePtr<void> address, int process_index,
150 ReadOptions options) const
152 mc_mem_region_t region = mc_get_snapshot_region((void*)address.address(), this, process_index);
154 const void* res = MC_region_read(region, buffer, (void*)address.address(), size);
155 if (buffer == res || options & ReadOptions::lazy())
158 memcpy(buffer, res, size);
162 return this->process()->read_bytes(buffer, size, address, process_index, options);
166 } // namespace simgrid
173 #include <sys/mman.h>
175 #include "src/mc/mc_config.hpp"
176 #include "src/mc/mc_mmu.hpp"
177 #include "src/mc/mc_private.hpp"
178 #include "src/mc/mc_snapshot.hpp"
180 XBT_TEST_SUITE("mc_snapshot", "Snapshots");
182 static inline void init_memory(void* mem, size_t size)
184 char* dest = (char*)mem;
185 for (size_t i = 0; i < size; ++i) {
186 dest[i] = rand() & 255;
190 static void test_snapshot(bool sparse_checkpoint);
192 XBT_TEST_UNIT("flat_snapshot", test_flat_snapshots, "Test flat snapshots")
197 XBT_TEST_UNIT("page_snapshots", test_per_snpashots, "Test per-page snapshots")
202 static void test_snapshot(bool sparse_checkpoint)
205 xbt_test_add("Initialization");
206 _sg_mc_sparse_checkpoint = sparse_checkpoint;
207 xbt_assert(xbt_pagesize == getpagesize());
208 xbt_assert(1 << xbt_pagebits == xbt_pagesize);
210 std::unique_ptr<simgrid::mc::RemoteClient> process(new simgrid::mc::RemoteClient(getpid(), -1));
212 mc_model_checker = new ::simgrid::mc::ModelChecker(std::move(process));
214 for (int n = 1; n != 256; ++n) {
216 // Store region page(s):
217 size_t byte_size = n * xbt_pagesize;
218 void* source = mmap(nullptr, byte_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
219 xbt_assert(source != MAP_FAILED, "Could not allocate source memory");
221 // Init memory and take snapshots:
222 init_memory(source, byte_size);
223 simgrid::mc::RegionSnapshot region0 =
224 simgrid::mc::sparse_region(simgrid::mc::RegionType::Unknown, source, source, byte_size);
225 for (int i = 0; i < n; i += 2) {
226 init_memory((char*)source + i * xbt_pagesize, xbt_pagesize);
228 simgrid::mc::RegionSnapshot region =
229 simgrid::mc::sparse_region(simgrid::mc::RegionType::Unknown, source, source, byte_size);
231 void* destination = mmap(nullptr, byte_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
232 xbt_assert(source != MAP_FAILED, "Could not allocate destination memory");
234 xbt_test_add("Reading whole region data for %i page(s)", n);
235 const void* read = MC_region_read(®ion, destination, source, byte_size);
236 xbt_test_assert(not memcmp(source, read, byte_size), "Mismatch in MC_region_read()");
238 xbt_test_add("Reading parts of region data for %i page(s)", n);
239 for (int j = 0; j != 100; ++j) {
240 size_t offset = rand() % byte_size;
241 size_t size = rand() % (byte_size - offset);
242 const void* read = MC_region_read(®ion, destination, (const char*)source + offset, size);
243 xbt_test_assert(not memcmp((char*)source + offset, read, size), "Mismatch in MC_region_read()");
246 xbt_test_add("Compare whole region data for %i page(s)", n);
248 xbt_test_assert(MC_snapshot_region_memcmp(source, ®ion0, source, ®ion, byte_size),
249 "Unexpected match in MC_snapshot_region_memcmp() with previous snapshot");
251 xbt_test_add("Compare parts of region data for %i page(s) with itself", n);
252 for (int j = 0; j != 100; ++j) {
253 size_t offset = rand() % byte_size;
254 size_t size = rand() % (byte_size - offset);
256 not MC_snapshot_region_memcmp((char*)source + offset, ®ion, (char*)source + offset, ®ion, size),
257 "Mismatch in MC_snapshot_region_memcmp()");
261 xbt_test_add("Read pointer for %i page(s)", n);
262 memcpy(source, &mc_model_checker, sizeof(void*));
263 simgrid::mc::RegionSnapshot region2 =
264 simgrid::mc::sparse_region(simgrid::mc::RegionType::Unknown, source, source, byte_size);
265 xbt_test_assert(MC_region_read_pointer(®ion2, source) == mc_model_checker,
266 "Mismtach in MC_region_read_pointer()");
269 munmap(destination, byte_size);
270 munmap(source, byte_size);
273 delete mc_model_checker;
274 mc_model_checker = nullptr;
277 #endif /* SIMGRID_TEST */