Question

我的代码使用OMP与#pragma omp critical，但没有#pragma omp barrier。然而，在Visual Studio 2008的调试版本中，我的程序崩溃了

Fatal User Error 1002: '#pragma omp barrier' improperly nested in '#pragma omp critical'

是否有可能自动插入#pragma omp barrier，可能是在try / catch块中？有没有办法获得更多的诊断信息，例如究竟存在哪个问题？

编辑：这是代码的结构。我使用omp critical来捕获和记住异常以及访问共享变量时。它是所有单行块。

std::vector<RunResult> runResults;
Evaluator evaluator;
std::vector<std::runtime_error> exceptionsDuringParallelExecution;
SomeType someVariable; //used as private variable later

#pragma omp parallel
            {
#pragma omp for private(someVariable)
                for (int monteCarloLoopCounter=monteCarloCounterOffset;monteCarloLoopCounter<numMonteCarloRuns+monteCarloCounterOffset;monteCarloLoopCounter++)
                {   
                    bool hasException = false;
#pragma omp critical(exceptionAccess)
                    {
                        hasException = exceptionsDuringParallelExecution.empty() == false;                      
                    }
                    if (hasException == false)
                    {


                        try
                        {
                            RunResult runRes;
                            //some nested loop:
                            for (unsigned int j = 0;j<10;j++)
                            {
                                while (someVariable->condition())
                                {
                                    for (unsigned int i=0;i<20; i++)
                                    {                               
                                        if (someCondition)
                                        {
                                            //calculate something

#pragma omp critical
                                            evaluator.evaluate(something);
                                        }
                                    }
                                }
                                runRes.setSomeResult();
                            }

#pragma omp critical
                            runResults.push_back(runRes);
                        }
                        catch (std::exception& e)
                        {
#pragma omp critical(exceptionAccess)
                            exceptionsDuringParallelExecution.push_back(std::runtime_error(e.what()));
                        }
                        catch (...)
                        {
#pragma omp critical(exceptionAccess)
                            exceptionsDuringParallelExecution.push_back(std::runtime_error("Unexpected exception"));
                        }
                    }
                }
            }

            if (exceptionsDuringParallelExecution.empty() == false)
            {
                throw exceptionsDuringParallelExecution.front();            
            }

Answer 1

我在你的代码中看到了四个#pragma omp critical指令（除了第一个之外的所有指令），这些指令不遵循紧跟括号括起来的块所需的语法。

The documentation显示了所需的语法：

#pragma omp critical [(name)]
{
   code_block
}

#pragma omp barrier由预处理器插入？

1 个答案: