--- /dev/null 2019-02-13 16:01:02.292000000 +0300 +++ new/src/os/windows/vm/iphlp_interface.cpp 2019-02-15 19:02:55.246211168 +0300 @@ -0,0 +1,104 @@ +/* + * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * 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 "iphlp_interface.hpp" +#include "runtime/os.hpp" + +// IPHLP API +typedef DWORD(WINAPI *GetIfTable2_Fn)(PMIB_IF_TABLE2*); +typedef DWORD(WINAPI *FreeMibTable_Fn)(PVOID); + +// IPHLP statics +GetIfTable2_Fn IphlpDll::_GetIfTable2 = NULL; +FreeMibTable_Fn IphlpDll::_FreeMibTable = NULL; + +LONG IphlpDll::_critical_section = 0; +LONG IphlpDll::_initialized = 0; +LONG IphlpDll::_iphlp_reference_count = 0; +HMODULE IphlpDll::_hModule = NULL; + +void IphlpDll::initialize(void) { + _hModule = os::win32::load_Windows_dll("iphlpapi.dll", NULL, 0); + + if (NULL == _hModule) { + return; + } + + // The 'A' at the end means the ANSI (not the UNICODE) vesions of the methods + _GetIfTable2 = (GetIfTable2_Fn)::GetProcAddress(_hModule, "GetIfTable2"); + _FreeMibTable = (FreeMibTable_Fn)::GetProcAddress(_hModule, "FreeMibTable"); + + // interlock is used for fencing + InterlockedExchange(&_initialized, 1); +} + +bool IphlpDll::IphlpDetach(void) { + LONG prev_ref_count = InterlockedExchangeAdd(&_iphlp_reference_count, -1); + BOOL ret = false; + + if (1 == prev_ref_count) { + if (_initialized && _hModule != NULL) { + ret = FreeLibrary(_hModule); + if (ret) { + _hModule = NULL; + _GetIfTable2 = NULL; + _FreeMibTable = NULL; + InterlockedExchange(&_initialized, 0); + } + } + } + return ret != 0; +} + +bool IphlpDll::IphlpAttach(void) { + InterlockedExchangeAdd(&_iphlp_reference_count, 1); + + if (1 == _initialized) { + return true; + } + + while (InterlockedCompareExchange(&_critical_section, 1, 0) == 1); + + if (0 == _initialized) { + initialize(); + } + + while (InterlockedCompareExchange(&_critical_section, 0, 1) == 0); + + return (_GetIfTable2 != NULL && _FreeMibTable != NULL); +} + +DWORD IphlpDll::GetIfTable2(PMIB_IF_TABLE2* Table) { + assert(_initialized && _GetIfTable2 != NULL, + "IphlpAttach() not yet called"); + + return _GetIfTable2(Table); +} + +DWORD IphlpDll::FreeMibTable(PVOID Memory) { + assert(_initialized && _FreeMibTable != NULL, + "IphlpAttach() not yet called"); + + return _FreeMibTable(Memory); +}