neobytes/src/allocators.cpp
Chuck 0b8f47dc53 Changing LockedPageManager to use a managed instance
This ensures the allocator is ready no matter when it's needed (as
some STL implementations allocate in constructors -- i.e., MSVC's STL
in debug builds).

Using boost::call_once to guarantee thread-safe static initialization.

Adding some comments describing why the change was made.

Addressing deinitialization of the LockedPageManager object
by initializing it in a local static initializer and adding
an assert in the base's destructor.
2013-10-20 14:29:24 +07:00

68 lines
1.7 KiB
C++

// Copyright (c) 2009-2013 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include "allocators.h"
#ifdef WIN32
#ifdef _WIN32_WINNT
#undef _WIN32_WINNT
#endif
#define _WIN32_WINNT 0x0501
#define WIN32_LEAN_AND_MEAN 1
#ifndef NOMINMAX
#define NOMINMAX
#endif
#include <windows.h>
// This is used to attempt to keep keying material out of swap
// Note that VirtualLock does not provide this as a guarantee on Windows,
// but, in practice, memory that has been VirtualLock'd almost never gets written to
// the pagefile except in rare circumstances where memory is extremely low.
#else
#include <sys/mman.h>
#include <limits.h> // for PAGESIZE
#include <unistd.h> // for sysconf
#endif
LockedPageManager* LockedPageManager::_instance = NULL;
boost::once_flag LockedPageManager::init_flag = BOOST_ONCE_INIT;
/** Determine system page size in bytes */
static inline size_t GetSystemPageSize()
{
size_t page_size;
#if defined(WIN32)
SYSTEM_INFO sSysInfo;
GetSystemInfo(&sSysInfo);
page_size = sSysInfo.dwPageSize;
#elif defined(PAGESIZE) // defined in limits.h
page_size = PAGESIZE;
#else // assume some POSIX OS
page_size = sysconf(_SC_PAGESIZE);
#endif
return page_size;
}
bool MemoryPageLocker::Lock(const void *addr, size_t len)
{
#ifdef WIN32
return VirtualLock(const_cast<void*>(addr), len);
#else
return mlock(addr, len) == 0;
#endif
}
bool MemoryPageLocker::Unlock(const void *addr, size_t len)
{
#ifdef WIN32
return VirtualUnlock(const_cast<void*>(addr), len);
#else
return munlock(addr, len) == 0;
#endif
}
LockedPageManager::LockedPageManager() : LockedPageManagerBase<MemoryPageLocker>(GetSystemPageSize())
{
}