= GIET-VM / Thread context access functions  =

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The [source:soft/giet_vm/giet_common/utils.c utils.c] and [source:soft/giet_vm/giet_common/utils.h utils.h] files define the functions used to access the thread contexts. The codes used to identify the various context slots are defined [source:soft/giet_vm/giet_kernel/ctx_handler.h here]. 

These functions are prefixed by "_" to remind that they can only be executed by a processor in kernel mode.


 === 1) unsigned int '''_get_thread_ltid'''( void ) ===
This function returns the local index of the calling thread (scheduler index).

 === 2) unsigned int '''_get_thread_trdid'''( void ) ===
This function returns the global thread identifier of the calling thread (x<<24 + y<<16 + p<<8 + ltid).

 === 3) unsigned int '''_get_task_slot'''( unsigned int x,  unsigned int y,  unsigned int p, unsigned int ltid, unsigned int slot ) ===
This function returns the content of a context slot for any thread running on any processor.
 * '''x''' : cluster x coordinate
 * '''y''' : cluster y coordinate
 * '''p''' : processor local index
 * '''ltid''' : task local index
 * '''slot''' : slot index

 === 4) void  '''_set_task_slot'''( unsigned int x, unsigned int y,  unsigned int p, unsigned int ltid, unsigned int slot,  unsigned int value ) ===
This function updates the content of a context slot for any thread running on any processor.
 * '''x''' : cluster x coordinate
 * '''y''' : cluster y coordinate
 * '''p''' : processor local index
 * '''ltid''' : task local index
 * '''slot''' : slot index

 === 5) unsigned int '''_get_context_slot'''( unsigned int slot ) ===
This function returns the content of a context slot for the calling thread.

 === 6) void '''_set_context_slot'''( unsigned int slot,  unsigned int value ) ===
This function updates the content of a context slot for the calling thread.