Sometimes the expansion may work and the memory address should stay the same.

[simgrid.git] / src / mc / sosp / PageStore.cpp

diff --git a/src/mc/sosp/PageStore.cpp b/src/mc/sosp/PageStore.cpp
index 0a070d4..e2c46f4 100644 (file)
--- a/src/mc/sosp/PageStore.cpp
+++ b/src/mc/sosp/PageStore.cpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2015-2020. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2015-2023. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -12,17 +12,14 @@
 #include "xbt/log.h"
 #include "xbt/sysdep.h"
 
-#if __cplusplus >= 201402L
-#include "src/include/xxhash.hpp"
-#endif
+#include "src/3rd-party/xxhash.hpp"
 #include "src/mc/mc_mmu.hpp"
 #include "src/mc/sosp/PageStore.hpp"
 
 #include <cstring> // memcpy, memcmp
 #include <unistd.h>
 
-namespace simgrid {
-namespace mc {
+namespace simgrid::mc {
 
 /** @brief Compute a hash for the given memory page
  *
@@ -34,18 +31,7 @@ namespace mc {
  */
 static XBT_ALWAYS_INLINE PageStore::hash_type mc_hash_page(const void* data)
 {
-#ifdef __cplusplus >= 201402L
   return xxh::xxhash<64>(data, xbt_pagesize);
-#else
-  const std::uint64_t* values = (const uint64_t*)data;
-  std::size_t n               = xbt_pagesize / sizeof(uint64_t);
-
-  // This djb2:
-  std::uint64_t hash = 5381;
-  for (std::size_t i = 0; i != n; ++i)
-    hash = ((hash << 5) + hash) + values[i];
-  return hash;
-#endif
 }
 
 // ***** snapshot_page_manager
@@ -55,8 +41,7 @@ PageStore::PageStore(std::size_t size) : capacity_(size)
   // Using mmap in order to be able to expand the region by relocating it somewhere else in the virtual memory space:
   void* memory =
       ::mmap(nullptr, size << xbt_pagebits, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
-  if (memory == MAP_FAILED)
-    xbt_die("Could not mmap initial snapshot pages.");
+  xbt_assert(memory != MAP_FAILED, "Could not mmap initial snapshot pages.");
 
   this->top_index_ = 0;
   this->memory_    = memory;
@@ -78,24 +63,23 @@ void PageStore::resize(std::size_t size)
   // virtual memory address if necessary:
 #if HAVE_MREMAP
   new_memory = mremap(this->memory_, old_bytesize, new_bytesize, MREMAP_MAYMOVE);
-  if (new_memory == MAP_FAILED)
-    xbt_die("Could not mremap snapshot pages.");
+  xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages.");
 #else
   if (new_bytesize > old_bytesize) {
     // Grow: first try to add new space after current map
     new_memory = mmap((char*)this->memory_ + old_bytesize, new_bytesize - old_bytesize, PROT_READ | PROT_WRITE,
                       MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
-    if (new_memory == MAP_FAILED)
-      xbt_die("Could not mremap snapshot pages.");
+    xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages.");
     // Check if expanding worked
-    if (new_memory != (char*)this->memory_ + old_bytesize) {
+    if (new_memory == (char*)this->memory_ + old_bytesize) {
+      new_memory = this->memory_;
+    } else {
       // New memory segment could not be put at the end of this->memory_,
       // so cancel this one and try to relocate everything and copy data
       munmap(new_memory, new_bytesize - old_bytesize);
       new_memory =
           mmap(nullptr, new_bytesize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0);
-      if (new_memory == MAP_FAILED)
-        xbt_die("Could not mremap snapshot pages.");
+      xbt_assert(new_memory != MAP_FAILED, "Could not mremap snapshot pages.");
       memcpy(new_memory, this->memory_, old_bytesize);
       munmap(this->memory_, old_bytesize);
     }
@@ -173,5 +157,4 @@ std::size_t PageStore::store_page(const void* page)
   return pageno;
 }
 
-} // namespace mc
-} // namespace simgrid
+} // namespace simgrid::mc