/*

* Copyright (c) Facebook, Inc. and its affiliates.

*

* This source code is licensed under the MIT license found in the

* LICENSE file in the root directory of this source tree.

*/

#ifndef HERMES_SUPPORT_THREADLOCAL_H

#define HERMES_SUPPORT_THREADLOCAL_H

#ifdef _WINDOWS

#error "ThreadLocal is not implemented because no code uses it in Windows"

#else

#include <hermes/Support/ErrorHandling.h>

#include <errno.h>

#include <pthread.h>

#include <stdlib.h>

namespace hermes {

/// Wrapper calls for thread local using pthread API.

/// Mainly copied from fbandroid/libraries/profilo/deps/fb/ThreadLocal.h

template <typename T>

class ThreadLocal {

public:

/// Constructor that has to be called from a thread-neutral place.

ThreadLocal() : key_(0) {

initialize();

}

/// Accessing thread local slot pointer via overloaded operator.

T *operator->() const {

return get();

}

/// Accessing thread local slot pointer via method call.

T *get() const {

return (T *)pthread_getspecific(key_);

}

/// Release and \return thread local slot.

T *release() {

T *obj = get();

pthread_setspecific(key_, nullptr);

return obj;

}

/// Set thread local slot to \p other.

void set(T *other = nullptr) {

T *old = (T *)pthread_getspecific(key_);

if (old != other) {

pthread_setspecific(key_, other);

}

}

private:

void initialize() {

int ret = pthread_key_create(&key_, nullptr);

if (ret != 0) {

const char *msg = "pthread_key_create failed: (unknown error)";

switch (ret) {

case EAGAIN:

msg =

"pthread_key_create failed: PTHREAD_KEYS_MAX (1024) is exceeded";

break;

case ENOMEM:

msg = "pthread_key_create failed: Out-of-memory";

break;

}

hermes_fatal(msg);

}

}

pthread_key_t key_;

};

} // namespace hermes

#endif // _WINDOWS

#endif // HERMES_SUPPORT_THREADLOCAL_H