#ifndef WLPDSTM_TLS_H_
#define WLPDSTM_TLS_H_
namespace wlpdstm {
///////////////////////
// invoke init start //
///////////////////////
template<typename T, bool INIT = true>
struct GlobalInitInvoker {
static void GlobalInit() {
T::GlobalInit();
}
};
template<typename T>
struct GlobalInitInvoker<T, false> {
static void GlobalInit() {
// do nothing
}
};
template<typename T, bool INIT = true>
struct ThreadInitInvoker {
static void ThreadInit(T *obj) {
obj->ThreadInit();
}
};
template<typename T>
struct ThreadInitInvoker<T, false> {
static void ThreadInit(T *obj) {
// do nothing
}
};
}
/////////////////////
// invoke init end //
/////////////////////
#ifdef USE_PTHREAD_TLS
#include <pthread.h>
namespace wlpdstm {
/**
* This is a TLS class that will put one instance of templated
* class into TLS storage and provide access to it. Assumption here
* is that the TLS class exposes default constructor. If this is
* not the case this class should be slightly changed.
*
*/
template<class T, bool GLOBAL_INIT, bool THREAD_INIT>
class Tls {
public:
static void GlobalInit();
static void ThreadInit();
static T *Get();
private:
static ::pthread_key_t tlsKey;
static ::pthread_key_t initKey;
};
}
template<class T, bool GLOBAL_INIT, bool THREAD_INIT> ::pthread_key_t wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::tlsKey;
template<class T, bool GLOBAL_INIT, bool THREAD_INIT> ::pthread_key_t wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::initKey;
template<class T, bool GLOBAL_INIT, bool THREAD_INIT>
inline void wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::GlobalInit() {
::pthread_key_create(&tlsKey, NULL);
GlobalInitInvoker<T, GLOBAL_INIT>::GlobalInit();
// not locally initialized
::pthread_key_create(&initKey, NULL);
::pthread_setspecific(initKey, (const void *)false);
}
template<class T, bool GLOBAL_INIT, bool THREAD_INIT>
inline void wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::ThreadInit() {
bool initialized = (bool)::pthread_getspecific(initKey);
if(!initialized) {
T *obj = new T();
::pthread_setspecific(tlsKey, (const void *)obj);
ThreadInitInvoker<T, THREAD_INIT>::ThreadInit(obj);
::pthread_setspecific(initKey, (const void *)true);
}
}
template<class T, bool GLOBAL_INIT, bool THREAD_INIT>
inline T *wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::Get() {
return (T *)::pthread_getspecific(tlsKey);
}
#else
namespace wlpdstm {
template<class T, bool GLOBAL_INIT, bool THREAD_INIT>
class Tls {
public:
static void GlobalInit() {
GlobalInitInvoker<T, GLOBAL_INIT>::GlobalInit();
}
static void ThreadInit() {
if(!init) {
val = new T();
ThreadInitInvoker<T, THREAD_INIT>::ThreadInit(val);
init = true;
}
}
static T *Get() {
return val;
}
private:
static __thread T *val;
static __thread bool init;
};
}
template<class T, bool GLOBAL_INIT, bool THREAD_INIT> __thread T* wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::val;
template<class T, bool GLOBAL_INIT, bool THREAD_INIT> __thread bool wlpdstm::Tls<T, GLOBAL_INIT, THREAD_INIT>::init;
#endif
#endif // WLPDSTM_TLS_H_
