C++ static constructors and SMP

Chris Johns chrisj at rtems.org
Wed Oct 23 19:29:31 UTC 2013

On 23/10/2013 10:31 pm, Joel Sherrill wrote:
> Is this a case of two threads running the init table or an application thread running and using a global object before running the init table is complete?

No just one thread as there is only 1 call to the code that manages the 
Init table and so creates and starts the Init task(s). The secondary 
core(s) are held waiting until all the initialisation of RTEMS is done 
then enter the multitasking state.

The start multitasking call releases the secondary core(s) (1 core in 
the case of the Zynq) and it enters the _Thread_Handler. We do not know 
if this is the Init task or an idle thread. If the idle thread core 
catches the ctor call it will head down that path. The primary core 
returns from starting the secondary core(s) and enters _Thread_Dispatch 
in the context of Init and continues to run it. If code in the Init uses 
an object yet to be constructed you break.

> Constructor order is another problem but I didn't think that had anything to do with this case.



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