greenplumn init 代码
文件路径：/src/backend/gporca/libnaucrates/src/init.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2010 Greenplum, Inc.
/
/ @filename:
/ init.cpp
/
/ @doc:
/ Implementation of initialization and termination functions for
/ libgpdxl.
/---------------------------------------------------------------------------
#include "naucrates/init.h"
#include <xercesc/framework/MemBufInputSource.hpp>
#include <xercesc/util/XMLString.hpp>
#include "gpos/memory/CAutoMemoryPool.h"
#include "naucrates/dxl/parser/CParseHandlerFactory.h"
#include "naucrates/dxl/xml/CDXLMemoryManager.h"
#include "naucrates/dxl/xml/dxltokens.h"
#include "naucrates/exception.h"
using namespace gpos;
using namespace gpdxl;
static CDXLMemoryManager *dxl_memory_manager = nullptr;
static CMemoryPool *pmpXerces = nullptr;
static CMemoryPool *pmpDXL = nullptr;
/ safe-guard to prevent initializing DXL support more than once
static ULONG_PTR m_ulpInitDXL = 0;
/ safe-guard to prevent shutting DXL support down more than once
static ULONG_PTR m_ulpShutdownDXL = 0;
/---------------------------------------------------------------------------
/ @function:
/ InitDXL
/
/ @doc:
/ Initialize DXL support; must be called before any library
/ function is called
/
/
/---------------------------------------------------------------------------
void
InitDXL()
{
if (0 < m_ulpInitDXL)
{
/ DXL support is already initialized by a previous call
return;
}
GPOS_ASSERT(nullptr != pmpXerces);
GPOS_ASSERT(nullptr != pmpDXL);
/ setup own memory manager
dxl_memory_manager = GPOS_NEW(pmpXerces) CDXLMemoryManager(pmpXerces);
/ initialize Xerces, if this fails library initialization should crash here
XMLPlatformUtils::Initialize(
XMLUni::fgXercescDefaultLocale, / locale
nullptr, / nlsHome: location for message files
nullptr, / panicHandler
dxl_memory_manager / memoryManager
);
/ initialize DXL tokens
CDXLTokens::Init(pmpDXL);
/ initialize parse handler mappings
CParseHandlerFactory::Init(pmpDXL);
m_ulpInitDXL++;
}
/---------------------------------------------------------------------------
/ @function:
/ ShutdownDXL
/
/ @doc:
/ Shutdown DXL support; called only at library termination
/
/---------------------------------------------------------------------------
void
ShutdownDXL()
{
if (0 < m_ulpShutdownDXL)
{
/ DXL support is already shut-down by a previous call
return;
}
GPOS_ASSERT(nullptr != pmpXerces);
m_ulpShutdownDXL++;
XMLPlatformUtils::Terminate();
CDXLTokens::Terminate();
GPOS_DELETE(dxl_memory_manager);
dxl_memory_manager = nullptr;
}
/---------------------------------------------------------------------------
/ @function:
/ gpdxl_init
/
/ @doc:
/ Initialize Xerces parser utils
/
/---------------------------------------------------------------------------
void
gpdxl_init()
{
/ create memory pool for Xerces global allocations
{
CAutoMemoryPool amp;
/ detach safety
pmpXerces = amp.Detach();
}
/ create memory pool for DXL global allocations
{
CAutoMemoryPool amp;
/ detach safety
pmpDXL = amp.Detach();
}
/ add standard exception messages
(void) EresExceptionInit(pmpDXL);
}
/---------------------------------------------------------------------------
/ @function:
/ gpdxl_terminate
/
/ @doc:
/ Terminate Xerces parser utils and destroy memory pool
/
/---------------------------------------------------------------------------
void
gpdxl_terminate()
{
#ifdef GPOS_DEBUG
ShutdownDXL();
if (nullptr != pmpDXL)
{
(CMemoryPoolManager::GetMemoryPoolMgr())->Destroy(pmpDXL);
pmpDXL = nullptr;
}
if (nullptr != pmpXerces)
{
(CMemoryPoolManager::GetMemoryPoolMgr())->Destroy(pmpXerces);
pmpXerces = nullptr;
}
#endif / GPOS_DEBUG
}
/ EOF