一個簡單的進程間鎖的例子,通過在父進程聲明,然後在fork出來的子進程變可以使用這個鎖的對象來進程數據訪問的互斥控制。直接看代碼吧。。
#ifndef _SHARE_LOCK_H_
#define _SHARE_LOCK_H_
//進程間mutex,在父進程定義,fork之後加鎖解鎖對父子進程間有效
class ShareMutex
{
public:
ShareMutex::ShareMutex();
ShareMutex::~ShareMutex();
void Lock();
void UnLock();
private:
pthread_mutex_t* m_pMutex;
};
//進程間讀寫鎖,fork之後加鎖解鎖對父子進程間有效
class ShareRwlock
{
public:
ShareRwlock::ShareRwlock();
ShareRwlock::~ShareRwlock();
void WrLock();
void RdLock();
void UnLock();
private:
pthread_rwlock_t* m_pRwlock;
};
#endif
#include "ShareMutex.h"
ShareMutex::ShareMutex()
{
m_pMutex = (pthread_mutex_t *)mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
pthread_mutexattr_t attr_perf;
pthread_mutexattr_init(&attr_perf));
pthread_mutexattr_setpshared(&attr_perf, PTHREAD_PROCESS_SHARED);
pthread_mutex_init(g_perf_mutex, &attr_perf);
}
ShareMutex::~ShareMutex()
{
m_pRwLocked_mutex_destroy(m_pMutex);
munmap(m_pMutex, sizeof(pthread_mutex_t));
}
//www.it165.net
void ShareMutex::Lock()
{
if(0 != pthread_mutex_lock(m_pMutex))
{
throw TCException("ShareMutex::Lock() exception!");
}
}
void ShareMutex::UnLock()
{
if(0 != pthread_mutex_unlock(m_pMutex))
{
throw TCException("ShareMutex::UnLock() exception!");
}
}
ShareRwlock::ShareRwlock()
{
m_pRwlock = (pthread_rwlock_t *)mmap(NULL, sizeof(pthread_rwlock_t), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
pthread_rwlockattr_t attr_pub;
pthread_rwlockattr_init( &attr_pub );
pthread_rwlockattr_setpshared( &attr_pub, PTHREAD_PROCESS_SHARED );
pthread_rwlock_init( m_pRwLock, &attr_pub );
}
ShareRwlock::~ShareRwlock()
{
pthread_rwlock_destroy(m_pRwlock);
munmap(m_pRwlock, sizeof(pthread_rwlock_t));
}
void ShareRwlock::WrLock()
{
if(0 != pthread_rwlock_wrlock( m_pRwLock ))
{
throw TCException("ShareRwlock::WrLock() exception!");
}
}
void ShareRwlock::RdLock()
{
if(0 != pthread_rwlock_rdlock( m_pRwLock ))
{
throw TCException("ShareRwlock::RdLock() exception!");
}
}
void ShareRwlock::UnLock()
{
if(0 != pthread_rwlock_unlock( m_pRwLock ))
{
throw TCException("ShareRwlock::UnLock() exception!");
}
}