greenplumn CWorker 源码

greenplumn CWorker 代码

文件路径：/src/backend/gporca/libgpos/src/task/CWorker.cpp

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2008 - 2010 Greenplum, Inc.
//
//	@filename:
//		CWorker.cpp
//
//	@doc:
//		Worker abstraction, e.g. thread
//---------------------------------------------------------------------------

#include "gpos/task/CWorker.h"

#include "gpos/common/syslibwrapper.h"
#include "gpos/memory/CMemoryPoolManager.h"
#include "gpos/string/CWStringStatic.h"
#include "gpos/task/CWorkerPoolManager.h"

using namespace gpos;

// host system callback function to report abort requests
bool (*CWorker::abort_requested_by_system)(void);


//---------------------------------------------------------------------------
//	@function:
//		CWorker::CWorker
//
//	@doc:
//		ctor
//
//---------------------------------------------------------------------------
CWorker::CWorker(ULONG stack_size, ULONG_PTR stack_start)
	: m_task(nullptr), m_stack_size(stack_size), m_stack_start(stack_start)
{
	GPOS_ASSERT(stack_size >= 2 * 1024 &&
				"Worker has to have at least 2KB stack");

	// register worker
	GPOS_ASSERT(nullptr == Self() && "Found registered worker!");

	CWorkerPoolManager::WorkerPoolManager()->RegisterWorker(this);
	GPOS_ASSERT(this == CWorkerPoolManager::WorkerPoolManager()->Self());
}


//---------------------------------------------------------------------------
//	@function:
//		CWorker::~CWorker
//
//	@doc:
//		dtor
//
//---------------------------------------------------------------------------
CWorker::~CWorker()
{
	// unregister worker
	GPOS_ASSERT(this == Self() && "Unidentified worker found.");
	CWorkerPoolManager::WorkerPoolManager()->RemoveWorker();
}


//---------------------------------------------------------------------------
//	@function:
//		CWorker::Execute
//
//	@doc:
//		Execute single task
//
//---------------------------------------------------------------------------
void
CWorker::Execute(CTask *task)
{
	GPOS_ASSERT(task);
	GPOS_ASSERT(nullptr == m_task && "Another task is assigned to worker");

	m_task = task;
	GPOS_TRY
	{
		m_task->Execute();
		m_task = nullptr;
	}
	GPOS_CATCH_EX(ex)
	{
		m_task = nullptr;
		GPOS_RETHROW(ex);
	}
	GPOS_CATCH_END;
}


//---------------------------------------------------------------------------
//	@function:
//		CWorker::CheckForAbort
//
//	@doc:
//		Check pending abort flag; throw if abort is flagged
//
//---------------------------------------------------------------------------
void
CWorker::CheckForAbort(const CHAR *, ULONG)
{
	// check if there is a task assigned to worker,
	// task is still running and CFA is not suspended
	if (nullptr != m_task && m_task->IsRunning() && !m_task->IsAbortSuspended())
	{
		GPOS_ASSERT(!m_task->GetErrCtxt()->IsPending() &&
					"Check-For-Abort while an exception is pending");

		if ((nullptr != abort_requested_by_system &&
			 abort_requested_by_system()) ||
			m_task->IsCanceled())
		{
			// raise exception
			GPOS_ABORT;
		}
	}
}


//---------------------------------------------------------------------------
//	@function:
//		CWorker::CheckStackSize
//
//	@doc:
//		Size of stack within context of this worker;
//		effectively calculates distance of local variable to stack start;
//		if stack space is exhausted we throw an exception;
//		else we check if requested space can fit in stack
//
//---------------------------------------------------------------------------
BOOL
CWorker::CheckStackSize(ULONG request) const
{
	ULONG_PTR ptr = 0;

	// get current stack size
	ULONG_PTR size = m_stack_start - (ULONG_PTR) &ptr;

	// check if we have exceeded stack space
	if (size >= m_stack_size)
	{
		// raise stack overflow exception
		GPOS_RAISE(CException::ExmaSystem, CException::ExmiOutOfStack);
	}

	// check if there is enough stack space for request
	if (size + request >= m_stack_size)
	{
		return false;
	}
	return true;
}


// EOF

相关信息

greenplumn 源码目录

相关文章

greenplumn CAutoSuspendAbort 源码

greenplumn CAutoTaskProxy 源码

greenplumn CAutoTraceFlag 源码

greenplumn CTask 源码

greenplumn CTaskContext 源码

greenplumn CTaskLocalStorage 源码

greenplumn CTaskSchedulerFifo 源码

greenplumn CWorkerPoolManager 源码

greenplumn ITask 源码

greenplumn IWorker 源码