Disabling dynamic memory allocation

In embedded applications it's often desirable to avoid dynamic memory allocation for performance and/or safety reasons. In its configuration process, liblightmodbus allows user to disable dynamic memory allocation.

Defining following CMake variables during configuration will have effect on the way memory is allocated in certain places:

• STATIC_MEM_SLAVE_REQUEST - replaces ModbusSlave::request frame pointer with fixed-size buffer
• STATIC_MEM_SLAVE_RESPONSE - replaces ModbusSlave::response frame pointer with fixed-size buffer
• STATIC_MEM_MASTER_REQUEST - replaces ModbusMaster::request frame pointer with fixed-size buffer
• STATIC_MEM_MASTER_RESPONSE - replaces ModbusMaster::response frame pointer with fixed-size buffer
• STATIC_MEM_MASTER_DATA - replaces ModbusMaster::data coil and registers data pointers with fixed-size buffers

Warning

STATIC_MEM_MASTER_DATA and NO_MASTER_DATA_BUFFER modules cannot be used at once.

For example, following CMake invocation configures the library so that the slave's request buffer is only 128 bytes long.

cmake -DSTATIC_MEM_SLAVE_REQUEST=128 ..

For more information on how to build the library, see Building liblightmodbus.