| | |
| | | #define MSG_5BILLZET |
| | | |
| | | #include <stdint.h> |
| | | #include "shm.h" |
| | | #include <boost/interprocess/offset_ptr.hpp> |
| | | |
| | | namespace bhome_shm { |
| | | |
| | | using namespace boost::interprocess; |
| | | |
| | | // safe to be stored in shared memory. |
| | | // msg is safe to be stored in shared memory, so POD data or offset_ptr is required. |
| | | // message format: header(meta) + body(data). |
| | | enum MsgType { |
| | | kMsgTypeNull = 0, |
| | |
| | | void Pack(void *p); |
| | | }; |
| | | |
| | | typedef offset_ptr<void> Msg; |
| | | // store ref count, msgs shareing the same data should also hold a pointer of the same RefCount object. |
| | | class RefCount : private boost::noncopyable |
| | | { |
| | | public: |
| | | int Inc() { Guard lk(mutex_); return ++num_; } |
| | | int Dec() { Guard lk(mutex_); return --num_; } |
| | | int Get() { Guard lk(mutex_); return num_; } |
| | | private: |
| | | Mutex mutex_; |
| | | int num_ = 0; |
| | | }; |
| | | |
| | | class Msg { |
| | | private: |
| | | offset_ptr<void> ptr_; |
| | | offset_ptr<RefCount> count_; |
| | | void swap(Msg &a) { std::swap(ptr_, a.ptr_); std::swap(count_, a.count_); } |
| | | public: |
| | | class CountGuard : private boost::noncopyable { |
| | | Msg &msg_; |
| | | public: |
| | | CountGuard(Msg &msg) : msg_(msg) { msg_.AddRef(); } |
| | | ~CountGuard() { msg_.RemoveRef(); } |
| | | }; |
| | | |
| | | Msg(void *p=0, RefCount *c=0):ptr_(p), count_(c) {} |
| | | |
| | | // ~Msg() { RemoveRef(); } |
| | | // Msg(const Msg &a):ptr_(a.ptr_), count_(a.count_) { AddRef(); } |
| | | // Msg(Msg &&a):ptr_(a.ptr_), count_(a.count_) { a.ptr_ = 0; a.count_ = 0; } |
| | | // Msg & operator = (const Msg &a) { Msg(a).swap(*this); } |
| | | // Msg & operator = (Msg &&a) { Msg(std::move(a)).swap(*this); } |
| | | |
| | | template <class T = void> T *get() { return static_cast<T*>(ptr_.get()); } |
| | | int AddRef() { return count_ ? count_->Inc() : 0; } |
| | | int RemoveRef() { return count_ ? count_->Dec() : 0; } |
| | | int Count() { return count_ ? count_->Get() : 0; } |
| | | }; |
| | | |
| | | |
| | | } // namespace bhome_shm |
| | | |