C++ 中實現C函數（同cpp文檔）extern"C"

1)標頭檔中extern"C"聲明C函數，樣本如下：

//LamSemaphore.h

#ifndef LAMSEMAPHORE_H
#define LAMSEMAPHORE_H
#include <Global.h>

extern "C"{//C函式宣告
    void* produce(void*);
    void* consume(void *);
}

class LamSemaphore{
public:
    LamSemaphore();
    virtual ~LamSemaphore();
    virtual void set(){};
    virtual void get(){};
public:
    pFun p_produce;
    pFun p_consume;
};
#endif // LAMSEMAPHORE_H

2)cpp檔案中定義C函數

//LamSemaphore.cpp

#include "LamSemaphore.h"

void* produce(void *arg){
    for(int i=0; i< nitems; ++i){
        sem_wait(&(shared->nempty));
        sem_wait(&(shared->mutex));
        qDebug("producen\n");
        shared->buff[i%NBUFF] = i;
        sem_post(&(shared->mutex));
        sem_post(&(shared->nstored));
    }
}
void* consume(void* arg){
    for(int i=0;i<nitems; ++i){
        sem_wait(&(shared->nstored));
        sem_wait(&(shared->mutex));
        qDebug("consume\n");
        if(shared->buff[i%NBUFF] != i){
            qDebug("buff[%d] = %d",i,shared->buff[i%NBUFF]);


        }
        sem_post(&(shared->mutex));
        sem_post(&(shared->nempty));
    }
}
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