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EM-ODP 4.4.0
Event Machine on ODP
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EM-ODP 4.4.0
Event Machine on ODP
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Data Structures | |
| struct | em_event_uarea_info_t |
| Event user area information filled by em_event_uarea_info() More... | |
Macros | |
| #define | em_event_uarea_get em_event_uarea |
| #define | em_event_uarea_id_get em_event_uarea_id |
Functions | |
| void * | em_event_uarea (em_event_t event, size_t *size) |
| Get a pointer to the event user area, optionally along with its size. | |
| em_status_t | em_event_uarea_id (em_event_t event, bool *isset, uint16_t *id) |
| Get the event user area ID along with information if it has been set. | |
| em_status_t | em_event_uarea_id_set (em_event_t event, uint16_t id) |
| Set the event user area ID. | |
| em_status_t | em_event_uarea_info (em_event_t event, em_event_uarea_info_t *uarea_info) |
| Get the event user area information for a given event. | |
An event may additionally contain a user area separate from the event payload. The size of the event user area is set when creating the event pool from which the event is allocated. The user area is a fixed size (per pool) data area into which event related state data can be stored without having to access and change the payload. Note that the size of the event user area can be zero(0), depending on event pool configuration. Note also that the user area content is not initialized by EM, neither em_alloc() nor em_free() will touch it and thus it might contain old user data set the last time the area was used during a previous allocation of the same event. Since the user area is not part of the event payload, it will not be transmitted as part of a packet etc. A user area ID can further be used to identify the user area contents. The event user area ID is stored outside of the user area itself and is thus always available, even if the size of the user area data is set to zero(0). See em_pool_create(), em_event_uarea(), em_event_uarea_id/set() and em_event_uarea_info() for more information on the event user area and its associated ID.
| #define em_event_uarea_get em_event_uarea |
Definition at line 985 of file event_machine_event.h.
| #define em_event_uarea_id_get em_event_uarea_id |
Definition at line 1020 of file event_machine_event.h.
| void * em_event_uarea | ( | em_event_t | event, |
| size_t * | size | ||
| ) |
Get a pointer to the event user area, optionally along with its size.
The event user area is a fixed sized area located within the event metadata (i.e. outside of the event payload) that can be used to store application specific event related data without the need to adjust the payload. The event user area is configured during EM event pool creation and thus the size of the user area is set per pool.
Note that the user area content is not initialized by EM, neither em_alloc() nor em_free() will touch it and thus it might contain old user data set the last time the area was used during a previous allocation of the same event. Since the user area is not part of the event payload, it will not be transmitted as part of a packet etc.
| event | Event handle to get the user area of | |
| [out] | size | Optional output arg into which the user area size is stored. Use 'size=NULL' if no size information is needed. |
| NULL | on error or if the event contains no user area |
Definition at line 1642 of file event_machine_event.c.
| em_status_t em_event_uarea_id | ( | em_event_t | event, |
| bool * | isset, | ||
| uint16_t * | id | ||
| ) |
Get the event user area ID along with information if it has been set.
The event user area can be associated with an optional ID that e.g. can be used to identify the contents of the actual user area data. The ID is stored outside of the actual user area data and is available for use even if the user area size has been set to zero(0) for the pool the event was allocated from.
This function is used to determine whether the user area ID has been set earlier and to retrieve the ID in the case it has been set. EM will initialize 'ID isset = false' when allocating a new event (indicating that the ID is not set). Use em_event_uarea_id_set() to set the ID.
| event | Event handle to get the user area ID and "set"-status of | |
| [out] | isset | Optional output arg: has the ID been set previously? At least one of 'isset' and 'id' must be given (or both). |
| [out] | id | Optional output arg into which the user area ID is stored if it has been set before. The output arg 'isset' should be used to determine whether 'id' has been set. Note: 'id' will not be touched if the ID has not been set earlier (i.e. when 'isset' is 'false'). At least one of 'isset' and 'id' must be given (or both). |
Definition at line 1701 of file event_machine_event.c.
| em_status_t em_event_uarea_id_set | ( | em_event_t | event, |
| uint16_t | id | ||
| ) |
Set the event user area ID.
The event user area can be associated with an optional ID that e.g. can be used to identify the contents of the actual user area data. The ID is stored outside of the actual user area data and is available for use even if the user area size has been set to 0 for the pool the event was allocated from.
This function is used to set the event user area ID for the given event. The 'set' operation overwrites any ID stored earlier. Use em_event_uarea_id() to check whether an ID has been set earlier and to retrieve the ID.
| event | Event handle for which to set the user area ID |
| id | The user area ID to set |
Definition at line 1679 of file event_machine_event.c.
| em_status_t em_event_uarea_info | ( | em_event_t | event, |
| em_event_uarea_info_t * | uarea_info | ||
| ) |
Get the event user area information for a given event.
Obtain information about the event user area for a certain given event. Information containing the user area pointer, size, as well as the ID is output via the 'uarea_info' struct. This API function combines the functionality of em_event_uarea() and em_event_uarea_id() for use cases where both the user area pointer as well as the ID is needed. Calling one API function instead of two might be faster due to a fewer checks and internal conversions.
The event user area is a fixed sized area located within the event metadata (i.e. outside of the event payload) that can be used to store application specific event related data without the need to adjust the payload. The event user area is configured during EM event pool creation and thus the size of the user area is set per pool.
Note that the user area content is not initialized by EM, neither em_alloc() nor em_free() will touch it and thus it might contain old user data set the last time the area was used during a previous allocation of the same event. Since the user area is not part of the event payload, it will not be transmitted as part of a packet etc.
The event user area can be associated with an optional ID that can be used to identify the contents of the actual user area data. The ID is stored outside of the actual user area data and is available for use even if the user area size has been set to zero(0) for the pool the event was allocated from. EM will initialize 'uarea_info.id.isset = false' when allocating a new event (indicating that the ID is not set).
| event | Event handle to get the user area information of. | |
| [out] | uarea_info | Output struct into which the user area information is stored. |
| EM_OK | Operation successful. |
| Other | Operation FAILED and no valid user area info could be obtained, 'uarea_info' is all NULL/zero(0) in this case. |
Definition at line 1738 of file event_machine_event.c.