core_mqtt_agent_message_interface.h File Reference

Functions to interact with queues. More...

#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

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Data Structures
struct	MQTTAgentMessageInterface_t
	Function pointers and contexts used for sending and receiving commands, and allocating memory for them. More...

Typedefs
typedef struct MQTTAgentMessageContext	MQTTAgentMessageContext_t
	Context with which tasks may deliver messages to the agent.
typedef bool(*	MQTTAgentMessageSend_t) (MQTTAgentMessageContext_t *pMsgCtx, MQTTAgentCommand_t *const *pCommandToSend, uint32_t blockTimeMs)
	Send a message to the specified context. Must be thread safe. More...
typedef bool(*	MQTTAgentMessageRecv_t) (MQTTAgentMessageContext_t *pMsgCtx, MQTTAgentCommand_t **pReceivedCommand, uint32_t blockTimeMs)
	Receive a message from the specified context. Must be thread safe. More...
typedef MQTTAgentCommand_t *(*	MQTTAgentCommandGet_t) (uint32_t blockTimeMs)
	Obtain a MQTTAgentCommand_t structure. More...
typedef bool(*	MQTTAgentCommandRelease_t) (MQTTAgentCommand_t *pCommandToRelease)
	Give a MQTTAgentCommand_t structure back to the application. More...

Detailed Description

Functions to interact with queues.

Typedef Documentation

MQTTAgentMessageSend_t

typedef bool(* MQTTAgentMessageSend_t) (MQTTAgentMessageContext_t *pMsgCtx, MQTTAgentCommand_t *const *pCommandToSend, uint32_t blockTimeMs)

Send a message to the specified context. Must be thread safe.

Parameters

[in]	pMsgCtx	An MQTTAgentMessageContext_t.
[in]	pCommandToSend	Pointer to address to send to queue.
[in]	blockTimeMs	Block time to wait for a send.

Returns

true if send was successful, else false.

MQTTAgentMessageRecv_t

typedef bool(* MQTTAgentMessageRecv_t) (MQTTAgentMessageContext_t *pMsgCtx, MQTTAgentCommand_t **pReceivedCommand, uint32_t blockTimeMs)

Receive a message from the specified context. Must be thread safe.

Parameters

[in]	pMsgCtx	An MQTTAgentMessageContext_t.
[out]	pReceivedCommand	Pointer to write address of received command.
[in]	blockTimeMs	Block time to wait for a receive.

Returns

true if receive was successful, else false.

MQTTAgentCommandGet_t

typedef MQTTAgentCommand_t *(* MQTTAgentCommandGet_t) (uint32_t blockTimeMs)

Obtain a MQTTAgentCommand_t structure.

Note

MQTTAgentCommand_t structures hold everything the MQTT agent needs to process a command that originates from application. Examples of commands are PUBLISH and SUBSCRIBE. The MQTTAgentCommand_t structure must persist for the duration of the command's operation.

Parameters

[in]

blockTimeMs

The length of time the calling task should remain in the Blocked state (so not consuming any CPU time) to wait for a MQTTAgentCommand_t structure to become available should one not be immediately at the time of the call.

Returns

A pointer to a MQTTAgentCommand_t structure if one becomes available before blockTimeMs time expired, otherwise NULL.

MQTTAgentCommandRelease_t

typedef bool(* MQTTAgentCommandRelease_t) (MQTTAgentCommand_t *pCommandToRelease)

Give a MQTTAgentCommand_t structure back to the application.

Note

MQTTAgentCommand_t structures hold everything the MQTT agent needs to process a command that originates from application. Examples of commands are PUBLISH and SUBSCRIBE. The MQTTAgentCommand_t structure must persist for the duration of the command's operation.

Parameters

[in]

pCommandToRelease

A pointer to the MQTTAgentCommand_t structure to return to the application. The structure must first have been obtained by calling an MQTTAgentCommandGet_t, otherwise it will have no effect.

Returns

true if the MQTTAgentCommand_t structure was returned to the application, otherwise false.