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++ Development Tools，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->Tool Settings->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;

struct worker *next;

} CThread_worker;

typedef struct

{

pthread_mutex_t queue_lock;

pthread_cond_t queue_ready;

CThread_worker *queue_head;

int shutdown;

pthread_t *threadid;

int max_thread_num;

int cur_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));

return 0;

}

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;

return 0;

}

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);

return NULL;

}

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);

return 0;

}

5、问题及解决方法

1）build project时出现“Error launching builder (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++->New CDT project wizard->Makefile Project下，找到 Binary Parser 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 ->Binary Parser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

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

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作者：流星

出处：http://blog.sina.com.cn/staratsky
本文出自 “流星的博客” 博客，请务必保留此出处http://staratsky.blog.51cto.com/2513234/1144703