xMessageBufferSpaceAvailable

Collaboration diagram for xMessageBufferSpaceAvailable:

message_buffer.h

size_t xMessageBufferSpaceAvailable( MessageBufferHandle_t xMessageBuffer );

Returns the number of bytes of free space in the message buffer.

configUSE_STREAM_BUFFERS must be set to 1 in for FreeRTOSConfig.h for xMessageBufferSpaceAvailable() to be available.

Parameters

xMessageBuffer

The handle of the message buffer being queried.

Returns

The number of bytes that can be written to the message buffer before the message buffer would be full. When a message is written to the message buffer an additional sizeof( size_t ) bytes are also written to store the message's length. sizeof( size_t ) is typically 4 bytes on a 32-bit architecture, so if xMessageBufferSpacesAvailable() returns 10, then the size of the largest message that can be written to the message buffer is 6 bytes.