Base class for representation of one case in multi chain select. More...
#include <mchain_select_ifaces.hpp>
Public Types | |
| using | handling_result_t = std::variant< so_5::mchain_receive_result_t, so_5::mchain_send_result_t > |
| The result of attempt of handling this case. More... | |
Public Member Functions | |
| select_case_t (mchain_t chain) | |
| Initialized constructor. More... | |
| select_case_t (const select_case_t &)=delete | |
| select_case_t (select_case_t &&)=delete | |
| virtual | ~select_case_t () |
| select_case_t * | query_next () const noexcept |
| select_case_t * | giveout_next () noexcept |
| void | set_next (select_case_t *next) noexcept |
| Set the next item in the current queue to which select_case belongs. More... | |
| void | notify () noexcept |
| Notification for all waiting select_cases. More... | |
| void | on_select_finish () noexcept |
| Reaction to the end of select work. More... | |
| virtual handling_result_t | try_handle (select_notificator_t ¬ificator)=0 |
| An attempt to handle this case. More... | |
| const mchain_t & | chain () const noexcept |
| Get the underlying mchain. More... | |
Protected Member Functions | |
| auto | extract (demand_t &demand) |
| Helper method for calling extract method of the target mchain. More... | |
| auto | push (const std::type_index &msg_type, const message_ref_t &message) |
| Helper method for calling push method of the target mchain. More... | |
Protected Attributes | |
| mchain_t | m_chain |
| Message chain to receive message from. More... | |
| select_notificator_t * | m_notificator = nullptr |
| Notificator to be used for notify sleeping thread. More... | |
| select_case_t * | m_next = nullptr |
| Next select_case in queue. More... | |
Detailed Description
Base class for representation of one case in multi chain select.
- Attention
- Objects of this class are not copyable nor moveable.
- Since
- v.5.5.16
Member Typedef Documentation
◆ handling_result_t
| using so_5::mchain_props::select_case_t::handling_result_t = std::variant< so_5::mchain_receive_result_t, so_5::mchain_send_result_t > |
The result of attempt of handling this case.
Constructor & Destructor Documentation
◆ select_case_t() [1/3]
|
inline |
Initialized constructor.
- Parameters
-
chain Message chain for that this select_case is created.
◆ select_case_t() [2/3]
|
delete |
◆ select_case_t() [3/3]
|
delete |
◆ ~select_case_t()
|
inlinevirtual |
Member Function Documentation
◆ chain()
|
inlinenoexcept |
Get the underlying mchain.
- Since
- v.5.5.17
◆ extract()
|
inlineprotected |
Helper method for calling extract method of the target mchain.
This method is intended to be called by a derived class. This helper is necessary because only select_case_t class is declared as friend for abstract_message_chain_t class. Classes that are derived from select_case_t are not friends for abstract_message_chain_t class and can't call protected/private methods of abstract_message_chain_t.
- Since
- v.5.7.0
◆ giveout_next()
|
inlinenoexcept |
Get the next item in the current queue to which select_case belongs at this moment and drop this pointer to nullptr value.
This method must be used if select_case object must be extracted from the current queue.
- See also
- select_case_t::m_next.
◆ notify()
|
inlinenoexcept |
Notification for all waiting select_cases.
This method is called by mchain if empty mchain becomes non-empty or if it is closed.
This method does notification for all members of select_case queue. It means that mchain calls notify() for the head of the queue and that head does notification for all other queue's members.
◆ on_select_finish()
|
inlinenoexcept |
Reaction to the end of select work.
- Attention
- This method must be called before return from select() function to ensure that mchain do not hold a pointer to non-existent select_case object.
- This method must not throw because it will be called from destructor of RAII wrappers.
◆ push()
|
inlineprotected |
Helper method for calling push method of the target mchain.
This method is intended to be called by a derived class. This helper is necessary because only select_case_t class is declared as friend for abstract_message_chain_t class. Classes that are derived from select_case_t are not friends for abstract_message_chain_t class and can't call protected/private methods of abstract_message_chain_t.
- Since
- v.5.7.0
- Parameters
-
msg_type Type of message/signal to be pushed. message Message/signal to be pushed.
◆ query_next()
|
inlinenoexcept |
Simple access to next item in the current queue to which select_case object belongs at this moment.
- See also
- select_case_t::m_next
◆ set_next()
|
inlinenoexcept |
Set the next item in the current queue to which select_case belongs.
- See also
- select_case_t::m_next.
◆ try_handle()
|
pure virtual |
An attempt to handle this case.
Implemented in so_5::mchain_props::details::send_select_case_t, and so_5::mchain_props::details::receive_select_case_t.
Member Data Documentation
◆ m_chain
|
protected |
Message chain to receive message from.
◆ m_next
|
protected |
Next select_case in queue.
A select_case object can be included in one of two different queues:
- in select queue inside mchain (in this case m_notificator is not nullptr). Next item in queue belongs to different select(). This item must be notified in notify() method.
- in ready to use select_case queue. The select_case is added to that queue when select_case in notified by mchain. The next item in queue belongs to the same select().
◆ m_notificator
|
protected |
Notificator to be used for notify sleeping thread.
Can be null. It means that select_case is not used in select queue for the mchain at that moment.
There are just two methods where m_notificator changes its value:
- try_handle() where m_notificator receives an actual pointer (m_notificator can become nullptr again in try_handle() if mchain has messages or was closed);
- on_select_finish() where m_notificator receives nullptr value if it wasn't null yet.
In the previous versions of SObjectizer m_notificator received nullptr value during notification of new messages arrival or closing of mchain. But this lead to data races and the behaviour was changed. Now m_notificator can hold an actual pointer even after notification was initiated.
The documentation for this class was generated from the following file:
