#include <unistd.h>
#include <string.h> // memcpy, memcp
+#include <sys/mman.h>
+
#include <boost/foreach.hpp>
#include <xbt.h>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_page_snapshot, mc,
"Logging specific to mc_page_snapshot");
-extern "C" {
-
-static void mc_read_pagemap(uint64_t* pagemap, size_t page_start, size_t page_count);
-
-}
-
// ***** Utility:
/** @brief Compte a hash for the given memory page
* @param data Memory page
* @return hash off the page
*/
-static inline uint64_t mc_hash_page(const void* data)
+static inline __attribute__ ((always_inline))
+uint64_t mc_hash_page(const void* data)
{
const uint64_t* values = (const uint64_t*) data;
size_t n = xbt_pagesize / sizeof(uint64_t);
// Using mmap in order to be able to expand the region
// by relocating it somewhere else in the virtual memory
// space:
- void * memory = ::mmap(NULL, size << xbt_pagebits, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS|MAP_POPULATE, -1, 0);
+ void * memory = ::mmap(NULL, 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.");
}
void s_mc_pages_store::resize(size_t size)
{
+ size_t old_bytesize = this->capacity_ << xbt_pagebits;
size_t new_bytesize = size << xbt_pagebits;
// Expand the memory region by moving it into another
// virtual memory address if necessary:
- void* new_memory = mremap(this->memory_, this->capacity_ << xbt_pagesize, new_bytesize, MREMAP_MAYMOVE);
+ void* new_memory = mremap(this->memory_, old_bytesize, new_bytesize, MREMAP_MAYMOVE);
if (new_memory == MAP_FAILED) {
xbt_die("Could not mremap snapshot pages.");
}
this->capacity_ = size;
this->memory_ = new_memory;
- this->page_counts_.resize(size);
+ this->page_counts_.resize(size, 0);
}
/** Allocate a free page
if (this->free_pages_.empty()) {
// Expand the region:
- if (top_index_ == this->capacity_) {
+ if (this->top_index_ == this->capacity_) {
// All the pages are allocated, we need add more pages:
this->resize(2 * this->capacity_);
}
void s_mc_pages_store::remove_page(size_t pageno)
{
this->free_pages_.push_back(pageno);
- void* page = mc_page_from_number(this->memory_, pageno);
+ const void* page = this->get_page(pageno);
uint64_t hash = mc_hash_page(page);
this->hash_index_[hash].erase(pageno);
}
// Otherwise, a new page is allocated in the page store and the content
// of the page is `memcpy()`-ed to this new page.
size_t pageno = alloc_page();
+ xbt_assert(this->page_counts_[pageno]==0, "Allocated page is already used");
void* snapshot_page = (void*) this->get_page(pageno);
memcpy(snapshot_page, page, xbt_pagesize);
page_set.insert(pageno);
return new s_mc_pages_store_t(500);
}
+void mc_pages_store_delete(mc_pages_store_t store)
+{
+ delete store;
+}
+
}
+
+#ifdef SIMGRID_TEST
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#include <memory>
+
+#include "mc/mc_page_store.h"
+
+static int value = 0;
+
+static void new_content(void* data, size_t size)
+{
+ memset(data, ++value, size);
+}
+
+static void* getpage()
+{
+ return mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+}
+
+extern "C" {
+
+XBT_TEST_SUITE("mc_page_store", "Page store");
+
+XBT_TEST_UNIT("base", test_mc_page_store, "Test adding/removing pages in the store")
+{
+ xbt_test_add("Init");
+ size_t pagesize = (size_t) getpagesize();
+ std::auto_ptr<s_mc_pages_store_t> store = std::auto_ptr<s_mc_pages_store_t>(new s_mc_pages_store(500));
+ void* data = getpage();
+ xbt_test_assert(store->size()==0, "Bad size");
+
+ xbt_test_add("Store the page once");
+ new_content(data, pagesize);
+ size_t pageno1 = store->store_page(data);
+ xbt_test_assert(store->get_ref(pageno1)==1, "Bad refcount");
+ const void* copy = store->get_page(pageno1);
+ xbt_test_assert(memcmp(data, copy, pagesize)==0, "Page data should be the same");
+ xbt_test_assert(store->size()==1, "Bad size");
+
+ xbt_test_add("Store the same page again");
+ size_t pageno2 = store->store_page(data);
+ xbt_test_assert(pageno1==pageno2, "Page should be the same");
+ xbt_test_assert(store->get_ref(pageno1)==2, "Bad refcount");
+ xbt_test_assert(store->size()==1, "Bad size");
+
+ xbt_test_add("Store a new page");
+ new_content(data, pagesize);
+ size_t pageno3 = store->store_page(data);
+ xbt_test_assert(pageno1 != pageno3, "New page should be different");
+ xbt_test_assert(store->size()==2, "Bad size");
+
+ xbt_test_add("Unref pages");
+ store->unref_page(pageno1);
+ xbt_assert(store->get_ref(pageno1)==1, "Bad refcount");
+ xbt_assert(store->size()==2, "Bad size");
+ store->unref_page(pageno2);
+ xbt_test_assert(store->size()==1, "Bad size");
+
+ xbt_test_add("Reallocate page");
+ new_content(data, pagesize);
+ size_t pageno4 = store->store_page(data);
+ xbt_test_assert(pageno1 == pageno4, "Page was not reused");
+ xbt_test_assert(store->get_ref(pageno4)==1, "Bad refcount");
+ xbt_test_assert(store->size()==2, "Bad size");
+}
+
+}
+
+#endif /* SIMGRID_TEST */