mingw无法编译多线程程序的问题及解决

爱被打了一巴掌 2022-05-27 04:57 515阅读 0赞

## mingw无法编译多线程程序的问题及解决 ##

在linux环境下，用gedit+gcc方式学习一段时间的c语言，发现自己越来越佩服linux的牛人了。  
居然不用IDE也能开发代码。我做不到，所以有回到了windows的怀抱。

mingw是windows版本的gnu c/c++工具集 主要包括编译器gcc,连接器make，调试器gdb  
Eclipse是很好用的开发Java的IDE，CDT的全称是C/C++ DevelopmentTools，是使Eclipse能够支持C/C++开发的插件。  
本人使用的开发环境如下:  
win7+eclipse +MinGW + CDT

本文的目的：  
1）使用eclipse、MingW独构建Windows版的c/c++开发环境  
2）编译并调通了一个多线程的程序  
eclipse、MingW的安装此处不做重点。

1、配置C/C++开发环境  
右击我的电脑，点属性->高级->环境变量。然后：  
1）在PATH里加入C:\\MinGW\\bin  
2）新建LIBRARY\_PATH变量，值设为C:\\MinGW\\lib，这是标准库的位置。  
3）新建C\_INCLUDE\_PATH变量，值设为C:\\MinGW\\include。  
4）新建CPLUS\_INCLUDE\_PATH变量，值为C:\\MinGW\\include\\c++\\3.4.2;C:\\MinGW\\include\\c++\\3.4.2\\mingw32;C:\\MinGW\\include\\c++\\3.4.2\\backward;C:\\MinGW\\include

2、设置eclipse的环境变量  
Eclipse的Project->Properties->C/C++Build->Environment中去查看对应的PATH变量  
主要是看有没有添加一个包含MinGW的bin目录的PATH变量。这个变量在创建工程的时候一般会自动添加。  
但如果没有正确设置PATH变量，编译的时候就会报错说不能运行g++或者gcc。

3、设置多线程动态链接库  
Project->Properties->C/C++Build->Settings->ToolSettings->GCC C++Linker->Libraries  
添加Libraries (-l): lpthread

4、一个简单的线程池的例子

\#include <stdio.h>  
\#include <stdlib.h>  
\#include <unistd.h>  
\#include <sys/types.h>  
\#include <pthread.h>  
\#include <assert.h>

typedef struct worker  
\{  
  
void\*(\*process) (void \*arg);  
void\*arg;  
structworker \*next;

\} CThread\_worker;

typedef struct  
\{  
pthread\_mutex\_t queue\_lock;  
pthread\_cond\_t queue\_ready;

CThread\_worker \*queue\_head;

intshutdown;  
pthread\_t \*threadid;  
  
intmax\_thread\_num;  
  
intcur\_queue\_size;

\} CThread\_pool;

int pool\_add\_worker (void \*(\*process) (void \*arg), void\*arg);  
void \*thread\_routine (void \*arg);

static CThread\_pool \*pool = NULL;  
void  
pool\_init (int max\_thread\_num)  
\{  
pool = (CThread\_pool \*) malloc (sizeof (CThread\_pool));

pthread\_mutex\_init(&(pool->queue\_lock), NULL);  
pthread\_cond\_init(&(pool->queue\_ready), NULL);

pool->queue\_head = NULL;

pool->max\_thread\_num = max\_thread\_num;  
pool->cur\_queue\_size = 0;

pool->shutdown = 0;

pool->threadid =  
(pthread\_t \*) malloc (max\_thread\_num \* sizeof (pthread\_t));  
int i =0;  
for (i = 0;i < max\_thread\_num; i++)  
\{  
pthread\_create(&(pool->threadid\[i\]), NULL,thread\_routine,  
NULL);  
\}  
\}

int  
pool\_add\_worker (void \*(\*process) (void \*arg), void \*arg)  
\{  
  
CThread\_worker \*newworker =  
(CThread\_worker \*) malloc (sizeof (CThread\_worker));  
newworker->process = process;  
newworker->arg = arg;  
newworker->next = NULL;

pthread\_mutex\_lock(&(pool->queue\_lock));  
  
CThread\_worker \*member = pool->queue\_head;  
if (member!= NULL)  
\{  
while (member->next != NULL)  
member = member->next;  
member->next = newworker;  
\}  
else  
\{  
pool->queue\_head = newworker;  
\}

assert (pool->queue\_head != NULL);

pool->cur\_queue\_size++;  
pthread\_mutex\_unlock(&(pool->queue\_lock));  
  
pthread\_cond\_signal(&(pool->queue\_ready));  
return0;  
\}

int  
pool\_destroy ()  
\{  
if(pool->shutdown)  
return -1;  
pool->shutdown = 1;

pthread\_cond\_broadcast(&(pool->queue\_ready));

int i;  
for (i = 0;i < pool->max\_thread\_num; i++)  
pthread\_join (pool->threadid\[i\], NULL);  
free (pool->threadid);

CThread\_worker \*head = NULL;  
while(pool->queue\_head != NULL)  
\{  
head = pool->queue\_head;  
pool->queue\_head =pool->queue\_head->next;  
free (head);  
\}  
  
pthread\_mutex\_destroy(&(pool->queue\_lock));  
pthread\_cond\_destroy(&(pool->queue\_ready));

free (pool);  
  
pool=NULL;  
return0;  
\}

void \* thread\_routine (void \*arg)  
\{  
printf ("starting thread 0x%x\\n", pthread\_self ());  
while(1)  
\{  
pthread\_mutex\_lock(&(pool->queue\_lock));  
  
while (pool->cur\_queue\_size == 0&&!pool->shutdown)  
\{  
printf ("thread 0x%x is waiting\\n", pthread\_self ());  
pthread\_cond\_wait(&(pool->queue\_ready),&(pool->queue\_lock));  
\}

if (pool->shutdown)  
\{  
  
pthread\_mutex\_unlock(&(pool->queue\_lock));  
printf ("thread 0x%x will exit\\n", pthread\_self ());  
pthread\_exit (NULL);  
\}

printf ("thread 0x%x is starting to work\\n", pthread\_self ());

assert (pool->cur\_queue\_size != 0);  
assert (pool->queue\_head != NULL);

pool->cur\_queue\_size--;  
CThread\_worker \*worker = pool->queue\_head;  
pool->queue\_head =worker->next;  
pthread\_mutex\_unlock(&(pool->queue\_lock));

(\*(worker->process))(worker->arg);  
free (worker);  
worker = NULL;  
\}  
pthread\_exit (NULL);  
\}

// 下面是测试代码

void \* myprocess (void \*arg)  
\{  
printf ("threadid is 0x%x, working on task %d\\n", pthread\_self(),\*(int \*) arg);  
\_sleep (1);  
returnNULL;  
\}

int main (int argc, char \*\*argv)  
\{  
pool\_init (3);

int\*workingnum = (int \*) malloc (sizeof (int) \* 10);  
int i;  
for (i = 0;i < 10; i++)  
\{  
workingnum\[i\] = i;  
pool\_add\_worker (myprocess, &workingnum\[i\]);  
\}  
  
\_sleep (5);  
  
pool\_destroy ();

free (workingnum);  
return0;  
\}

5、问题及解决方法  
1）build project时出现“Error launchingbuilder (make -k all )”  
先将C:\\MinGW\\bin底下的  
mingw32-make.exe更名为make.exe，因为在Eclipse使用时它预设会抓系统里make这个文件名而不是mingw32-make.

2）build project时出现“launch failed,binary not found”  
报错是因为没有指定编译器。为了让CDT能够采用MinGW进行编译，需要在 Eclipse 中进行设定  
方法一：去Window->Preferences->C/C++->NewCDT project wizard->Makefile Project下，找到 BinaryParser 取消 Elf Parser 改选 PE Windows Parser。或是其他编译器，看具体情况而定，  
当然你也可以指定GNU ELF Parser。  
方法二：去projrct -> properties -> c/c++build -> settings ->BinaryParser下设置一下，比如使用GNU Elf Parser

3）undefined reference to 'pthread\_create'  
undefined reference to'pthread\_join'  
问题原因：  
pthread 库不是 Linux 系统默认的库，由于Mingw下没有带，所以在项目中设置多线程动态链接库，也不管用。  
[ftp://sourceware.org/pub/pthreads-win32/pthreads-w32-2-8-0-release.exe][ftp_sourceware.org_pub_pthreads-win32_pthreads-w32-2-8-0-release.exe]  
解开pthreads-w32-2-8-0-release.exe，把Pre-built.2中的libpthreadGC2.a改名为libpthread.a复制到c:\\mingw\\lib目录，  
pthread.h复制到c: \\mingw\\include目录即可解决

本文欢迎转载，转载请注明作者与出处  
作者：流星  
出处：[http://blog.sina.com.cn/staratsky][http_blog.sina.com.cn_staratsky]

https://blog.csdn.net/yi412/article/details/64920385

[ftp_sourceware.org_pub_pthreads-win32_pthreads-w32-2-8-0-release.exe]: ftp://sourceware.org/pub/pthreads-win32/pthreads-w32-2-8-0-release.exe
[http_blog.sina.com.cn_staratsky]: http://blog.sina.com.cn/staratsky