Provide partial RTOS API for bare metal builds - things that
can be done in a single threaded environment.
Allows more code to work in both RTOS and bare metal builds without
change, and in particular gives easy access to the ability to
efficiently wait for something occurring in interrupt.
Available in bare-metal:
* ThisThread
* osThreadFlagsSet to set flags on main thread (can be set from IRQ)
* EventFlags (can be set from IRQ)
* Semaphores (can be released from IRQ)
* Mutex (dummy implementation)
Not useful:
* ConditionVariable (could only be signalled from 2nd thread)
* RtosTimer (calls in a second thread context)
* Thread
Unimplemented:
* Mail, Queue, MemoryPool
Possible future work:
* ConditionVariableCS to act as IRQ signalled ConditionVariable
Replace the hardcoded value calculation of the memory pool block size
with the RTX preprocessor macro (via a shim layer).
This is in preparation for the replacement of the direct access of RTX
functionalities in Mbed OS with an access via CMSIS.
Various RTOS classes were storing their CMSIS-RTOS creation attribute
structure as a member, when it's not required after construction. Reduce
memory by eliminating this member.
Provide fix for pool buffer size: pool block size must be
a multiple of 4 bytes.
Add assertion to forbid creation of MemoryPool object with queue size equal to 0.
Update description of free() function. Add information about
statuses returned by this function.
Kevin Bracey
Hugues Kamba
Cruz Monrreal
Martin Kojtal
Amanda Butler
Bartek Szatkowski
Martin Kojtal
Senthil Ramakrishnan
Przemyslaw Stekiel
Jimmy Brisson
Vincent Coubard
Kevin Gilbert
Christopher Haster