The FreeRTOS kernel is now an MIT licensed AWS open source project, and these pages are being updated accordingly.

Quality RTOS & Embedded Software About   Contact   Support   FAQ   Download Menu      Quick Start Supported MCUs PDF Books Trace Tools Ecosystem Quick Start Guide Support Forum ⇓ Download Source ⇓ FreeRTOS+ Ecosystem  FreeRTOS+TCP:  Thread safe TCP/IP stack  SafeRTOS:  TUV certified RTOS  OpenRTOS:  Commercial Licensed RTOS  Fail Safe File System:  Ensures data integrity  FreeRTOS BSPs:  3rd party driver packages  Trace & Visualisation:  Tracealyzer for FreeRTOS  CLI:  Command line interface  WolfSSL SSL / TLS:  Networking security protocols  RTOS Training:  Delivered online or on-site  IO:  read(), write(), ioctl() interface FreeRTOS+ Lab Projects  FreeRTOS+POSIX:  POSIX threading API  FreeRTOS+FAT:  Thread aware file system Hint: Use the tree menu to navigate groups of related pages   xMessageBufferSpacesAvailable() [RTOS Message Buffer API] message_buffer.h size_t xMessageBufferSpacesAvailable( MessageBufferHandle_t xMessageBuffer ); Queries a message buffer to see how much free space it contains, which is equal to the amount of data that can be sent to the message buffer before it is full. The returned value is 4 bytes larger than the maximum message size that can be sent to the message buffer. Message buffer functionality is enabled by including the FreeRTOS/source/stream_buffer.c source file in the build (as message buffers use stream buffers). 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. [ Back to the top ]    [ About FreeRTOS ]    [ Privacy ]    [ Sitemap ]    [ ] Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News NXP tweet showing LPC5500 (ARMv8-M Cortex-M33) running FreeRTOS. Meet Richard Barry and learn about running FreeRTOS on RISC-V at FOSDEM 2019 Version 10.1.1 of the FreeRTOS kernel is available for immediate download. MIT licensed. View a recording of the "OTA Update Security and Reliability" webinar, presented by TI and AWS. Careers FreeRTOS and other embedded software careers at AWS. FreeRTOS Partners