Deployment Of Services Within A Multi-Threaded Application - Analog Devices VisualDSP++ 5.0 Service Manual

RTOS Considerations
for exclusive use by VDK and must not be managed by the inter-
rupt manager. IVG15 is also excluded from most VisualDSP++
applications as it is used to run the applications in supervisor
mode.
• Deferred callbacks – The deferred callback manager offers a simi-
lar service to the VDK process running at IVG14. It is highly
recommended that the VDK variant of the system services library is
used (and indeed the default VDK
variant essentially passes callbacks posted to the DCB manager to
the VDK level 14 process. In this mode of operation, only one call-
back queue can be used. If the standalone library variant is used,
several queues can be managed but none of them can be assigned to
the IVG 14 level as this would conflict with the VDK process run-
ning at that level.
Deployment of Services Within a Multi-Threaded
Application
Bear in mind these two major considerations when deploying system ser-
vices and the device driver model within a multi-threaded application.
• Critical regions – System services and device drivers use critical
regions where atomicity of a code segment is required. These
regions are managed through calls to the
adi_int_EnterCriticalRegion
adi_int_ExitCriticalRegion
adi_int_xxx.c
see "Interrupt Manager" on page
functions are used within threads that use system services rather
than the VDK push/pop critical region functions.
• Initialization – Initialization of system services and the device
manager is performed only once per application. Since their use
may be required in several threads, it is important that the
1-18
function and the
function, which are defined in the
files within the installation.
2-1.) It is advised that the above
VisualDSP++ 5.0 Device Drivers and System
Services Manual for Blackfin Processors
files ensure its use). This
.ldf
(For more information,