我想利用pthread
广告,因此要使用-lpthread
标志进行编译,但这是我得到的:
$ g++ -lpthread pseudo_code.cpp
/tmp/cc3mPrvt.o: In function `MyThreadClass::StartInternalThread()':
pseudo_code.cpp:(.text._ZN13MyThreadClass19StartInternalThreadEv[_ZN13MyThreadClass19StartInternalThreadEv]+0x26): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
我尝试编译的代码如下:
#include <pthread.h>
#include <iostream>
#include <vector>
#define OK 0
#define ERROR -1
//-- ThreadClass
class MyThreadClass
{
public:
MyThreadClass() {/* empty */}
virtual ~MyThreadClass() {/* empty */}
/** Returns true if the thread was successfully started, false if there was an error starting the thread */
bool StartInternalThread()
{
return (pthread_create(&_thread, NULL, InternalThreadEntryFunc, this) == 0);
}
/** Will not return until the internal thread has exited. */
void WaitForInternalThreadToExit()
{
(void) pthread_join(_thread, NULL);
}
protected:
/** Implement this method in your subclass with the code you want your thread to run. */
virtual void InternalThreadEntry() = 0;
private:
static void * InternalThreadEntryFunc(void * This) {
((MyThreadClass *)This)->InternalThreadEntry(); return NULL;
}
pthread_t _thread;
};
//-- /ThreadClass
//--- DUMMY DECLARATIONS BELOW TO MAKE IT COMPILE ---//
#define LOG_NS_ERROR std::cout
class test{
public:
int get_child(std::string x){return OK;};
};
test *_global;
typedef struct test_struct{} _db_transact;
class db_transact{
public:
db_transact(int,int&,int&){};
};
int _ns;
int _log_id;
//--- DUMMY DECLARATIONS ABOVE TO MAKE IT COMPILE ---//
class db_c_hndlr : public MyThreadClass{
public:
db_c_hndlr(void);
~db_c_hndlr(void);
db_transact *db_conn_get(void);
void InternalThreadEntry(void *func);
private:
int _stop;
std::vector<db_transact*> _db_pool;
};
//---------------------------------------------------------
db_c_hndlr::db_c_hndlr(void) {
}
//---------------------------------------------------------
void db_c_hndlr::InternatThreadEntry(void *func) {
while(!stop){
std::cout << "going!" << std::endl;
sleep(1);
}
}
//---------------------------------------------------------
db_c_hndlr::~db_c_hndlr() {
int i = 0;
std::vector<db_transact*>::iterator it;
for (i=0, it = _db_pool.begin();it!=_db_pool.end();it++, i++) {
if (_db_pool[i])
if (_db_pool[i]!=NULL)
delete _db_pool[i];
}
}
//---------------------------------------------------------
db_transact *db_c_hndlr::db_conn_get(void) {
db_transact *tmp;
tmp = new db_transact(_global->get_child("db_config"), _ns, _log_id);
_db_pool.push_back(tmp);
return tmp;
}
//---------------------------------------------------------
int main(void)
{
db_transact *conn=NULL;
db_c_hndlr db;
//db = new db_c_hndlr();
conn= db.db_conn_get();
return OK;
}
可能您需要这样做:
extern "C" {
#include <pthread.h>
}
这告诉编译器此标头用于C库,并且不应使用C ++名称修饰。
您还需要使用-pthread
代替-lpthread
,因为pthread库是特殊的,并且GCC希望明确地知道您正在尝试使用线程,而不是简单地链接到libpthread。
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我来说两句