en:docs:os2:api:vio

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en:docs:os2:api:vio [2021/09/14 08:37] – prokusheven:docs:os2:api:vio [2021/09/14 09:51] (current) – prokushev
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 Application calls VioGetAnsi in VIOCALLS Application calls VioGetAnsi in VIOCALLS
 VioGetAnsi calls VioRoute VioGetAnsi calls VioRoute
-if AVS registered then VioRoute calls AVS VioGetAnsi +if AVS registered then 
-  if AVS VioGetAnsi requires to call BVS then Call BVS VioGetAnsi +  VioRoute calls AVS VioGetAnsi 
-else call BVS VioGetAnsi+  if AVS VioGetAnsi requires to call BVS then 
 +    VioRouter сalls BVS VioGetAnsi 
 +else 
 +  VioRouter calls BVS VioGetAnsi
 Return to application Return to application
 </code> </code>
 +
 OS/2 1.1 introduced Program Manager and VIO was extended to support windowed OS/2 text-based sessions. This extended Vio was named as Advanced VIO. OS/2 1.1 introduced Program Manager and VIO was extended to support windowed OS/2 text-based sessions. This extended Vio was named as Advanced VIO.
  
Line 59: Line 63:
 </diagram> </diagram>
  
-In OS/2 2.0 and later VIO still 16-bit. In late OS/2 versions (3.x?) actual code of Video subsystem and Base Video Subsysten was moved to DOSCALLS.DLL (see Fig). VIOCALLS and BVSCALLS is a forwarders to DOSCALLS. As not part of official OS/2 distribution three independed versions of 32-to-16 bit wrapper subsystems was developed (See Fig). EXMWRAP.DLL was part of eComstation 1.0 and later releases.+In pseudo code it looks like this
  
 +<code>
 +Application calls VioGetAnsi in VIOCALLS
 +VioGetAnsi calls VioRoute
 +if AVS registered then
 +  VioRoute calls AVS VioGetAnsi
 +  if AVS VioGetAnsi requires to call BVS then
 +    VioRouter сalls BVS VioGetAnsi
 +else
 +  VioRouter calls BVS VioGetAnsi
 +If GVS registered then
 +  VioRouter calls GVS VioGetAnsi
 +Return to application
 +</code>
 +
 +In OS/2 2.0 and later VIO still 16-bit. In late OS/2 versions (3.x?) actual code of Video subsystem and Base Video Subsysten was moved to DOSCALLS.DLL (see Fig). VIOCALLS and BVSCALLS is a forwarders to DOSCALLS. 
 +
 +As not part of official OS/2 distribution three independed versions of 32-to-16 bit wrapper subsystems was developed (See Fig). EXMWRAP.DLL was part of eComstation 1.0 and later releases.
  
 <diagram> <diagram>
Line 89: Line 110:
 |DDD|DDD=Global Video Subsystem |DDD|DDD=Global Video Subsystem
 </diagram> </diagram>
 +
 +<code>
 +Application calls VioGetAnsi in VIOCALLS
 +VIOCALLS forwards to DOSCALLS
 +VioGetAnsi calls VioRoute
 +if AVS registered then
 +  VioRoute calls AVS VioGetAnsi
 +  if AVS VioGetAnsi requires to call BVS then
 +    VioRouter сalls BVS VioGetAnsi
 +    BVSCALLS forwards to DOSCALLS
 +else
 +  VioRouter calls BVS VioGetAnsi
 +  BVSCALLS forwards to DOSCALLS
 +If GVS registered then
 +  VioRouter calls GVS VioGetAnsi
 +Return to application
 +</code>
  
 osFree attempts to combine all aproaches and provide following callflow osFree attempts to combine all aproaches and provide following callflow