Ejemplo n.º 1
0
 * But for hashtable entry allocation site object, things get tricky. C runtime not only allocates
 * memory for it, but also calls its constructor at some later time. If we initialize the allocation site
 * at the first os::malloc() call, the object will be reinitialized when its constructor is called
 * by C runtime.
 * To workaround above issue, we declare a static size_t array with the size of the CallsiteHashtableEntry,
 * the memory is used to instantiate CallsiteHashtableEntry for the hashtable entry allocation site.
 * Given it is a primitive type array, C runtime will do nothing other than assign the memory block for the variable,
 * which is exactly what we want.
 * The same trick is also applied to create NativeCallStack object for CallsiteHashtableEntry memory allocation.
 *
 * Note: C++ object usually aligns to particular alignment, depends on compiler implementation, we declare
 * the memory as size_t arrays, to ensure the memory is aligned to native machine word alignment.
 */

// Reserve enough memory for NativeCallStack and MallocSiteHashtableEntry objects
size_t MallocSiteTable::_hash_entry_allocation_stack[CALC_OBJ_SIZE_IN_TYPE(NativeCallStack, size_t)];
size_t MallocSiteTable::_hash_entry_allocation_site[CALC_OBJ_SIZE_IN_TYPE(MallocSiteHashtableEntry, size_t)];

// Malloc site hashtable buckets
MallocSiteHashtableEntry*  MallocSiteTable::_table[MallocSiteTable::table_size];

// concurrent access counter
volatile int MallocSiteTable::_access_count = 0;

// Tracking hashtable contention
NOT_PRODUCT(int MallocSiteTable::_peak_count = 0;)


/*
 * Initialize malloc site table.
 * Hashtable entry is malloc'd, so it can cause infinite recursion.
Ejemplo n.º 2
0
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */
#include "precompiled.hpp"

#include "runtime/threadCritical.hpp"
#include "services/virtualMemoryTracker.hpp"

size_t VirtualMemorySummary::_snapshot[CALC_OBJ_SIZE_IN_TYPE(VirtualMemorySnapshot, size_t)];

void VirtualMemorySummary::initialize() {
  assert(sizeof(_snapshot) >= sizeof(VirtualMemorySnapshot), "Sanity Check");
  // Use placement operator new to initialize static data area.
  ::new ((void*)_snapshot) VirtualMemorySnapshot();
}

SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>* VirtualMemoryTracker::_reserved_regions;

int compare_committed_region(const CommittedMemoryRegion& r1, const CommittedMemoryRegion& r2) {
  return r1.compare(r2);
}

int compare_reserved_region_base(const ReservedMemoryRegion& r1, const ReservedMemoryRegion& r2) {
  return r1.compare(r2);