MessageQ_alloc enables interrupts

Elron A Yellin

Other Parts Discussed in Thread: SYSBIOS

MessageQ_alloc eventually calls down to Task_restore which enables interrupts via Hwi_enable, regardless of the state of GIE at entry. Is this a bug? It's bad for composability.

over 13 years ago

0 Steven Connell over 13 years ago

TI__Mastermind 45025 points

Hi Elron A Yellin,

Where is the call to Task_restore() that you are referring to?

It may help to know the versions of SYS/BIOS and IPC you are using.

Steve

0 Elron A Yellin over 13 years ago in reply to Steven Connell

Expert 1040 points

SYSBIOS 6.35.4.50, IPC 1.25.2.12

MessageQ_alloc
GateMP_leave
xdc_runtime_IGateProvider_leave
ti_sdo_ipc_gates_GatePeterson_leave__E
xdc_runtime_IGateProvider_leave
ti_sysbios_gates_GateSwi_leave__E
Swi_restore
Task_restore

Thanks Steve,

Elron

0 Steven Connell over 13 years ago in reply to Elron A Yellin

TI__Mastermind 45025 points

Hi Elron,

I've searched through all of the IPC code and I am not seeing a call to Task_restore in MessageQ_alloc, or anywhere else in the IPC code.

Perhaps I am missing it. Could you show me where you are seeing that in the code?

Steve

0 Elron A Yellin over 13 years ago in reply to Steven Connell

Expert 1040 points

Follow the call chain I posted, in particular

MessageQ_alloc
GateMP_leave
ti_sysbios_gates_GateSwi_leave__E
Swi_restore
Task_restore

0 Steven Connell over 13 years ago in reply to Elron A Yellin

TI__Mastermind 45025 points

Elron,

Yes, I was able to find it ... it's coming from the HeapMP_alloc call.

Furthermore, I've discussed with my colleague and the Hwi_disable/enable pair that's in Task_restore is there by design. It's needed because the call to Task_schedule (that's in Task_restore) could result in a Task context switch.

Lastly, since MessageQ_alloc blocks, it is expected that interrupts will be enabled upon return (and this assumption should be made for any function that blocks - interrupts will be enabled upon returning from the call to such a function).

Steve

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MessageQ_alloc enables interrupts