在没有文件 I/O 的情况下检索可重入词法分析的结果

发布于 2024-12-09 15:30:42 字数 913 浏览 3 评论 0原文

我在 C++ 项目中有一个 Flex 模块，我想从多个线程调用它。我的 .lex 文件的选项包括堆栈和可重入。假设可以同时从不同线程对不同扫描仪对象调用 yylex 并且一个词法分析序列不会阻止另一个词法分析序列（我认为是这种情况，但我不完全确定），如何做我恢复其中每一个的输出？我看到的唯一工具是 yyset_out(FILE* handle, yyscan_t Scanner)，但我不想必须使用文件，因为我只想要词法分析的结果，而不必进行文件写入。

我设置输入为：

void scanProcedure(...threadInfo...) {
   yyscan_t tscanner;

   yylex_init(tscanner);
   yy_scan_string(threadInfo->lexMe, tscanner);
   yylex(tscanner);

   /* how to retrieve results of lexing in a 
      reentrant manner ( no global state info ) 
      without having to do any file i/o */

   /* threadInfo-> ?? */

   yylex_destroy(tscanner);
}

...

pthread_create( ... scanProcedure ... threadInfoA ... );
pthread_create( ... scanProcedure ... threadInfoB ... );
pthread_create( ... scanProcedure ... threadInfoC ... );

pthread_join( ... );

另外，我意识到我可以在临时文件上调用 yyset_out ，然后访问文件缓冲区，但在我看来，似乎应该有一个比这更漂亮（更少黑客）的解决方案。

原文

I have a flex module in a C++ project that I want to call from multiple threads.
My .lex file's options include stack and reentrant.
Assuming that it is possible to call yylex on different scanner objects from different threads simultaneously and not have one lexing sequence block the other (which I think is the case but i'm not entirely sure), how do I recover the output for each of these? The only facility I see for this is yyset_out(FILE* handle, yyscan_t scanner), but I don't want to have to have to use files because I only want the results of the lexing without having to do a file write.

I set the input with:

void scanProcedure(...threadInfo...) {
   yyscan_t tscanner;

   yylex_init(tscanner);
   yy_scan_string(threadInfo->lexMe, tscanner);
   yylex(tscanner);

   /* how to retrieve results of lexing in a 
      reentrant manner ( no global state info ) 
      without having to do any file i/o */

   /* threadInfo-> ?? */

   yylex_destroy(tscanner);
}

...

pthread_create( ... scanProcedure ... threadInfoA ... );
pthread_create( ... scanProcedure ... threadInfoB ... );
pthread_create( ... scanProcedure ... threadInfoC ... );

pthread_join( ... );

Also, I realize that I could call yyset_out on a temporary file and then access the file buffer but it seems to me as though there should be a prettier (less hackish) solution than that.

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