View source for CONTEXTRECORD

== CONTEXTRECORD ==

Machine specific register contents for the thread at the time of the exception. 

=== Type ===
 
 typedef struct _CONTEXTRECORD {
 [[OS2 API:DataType:ULONG|ULONG]] ContextFlags;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_env[7];
 [[OS2 API:DataType:FPREG|FPREG]] ctx_stack[8];
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegGs;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegFs;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegEs;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegDs;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEdi;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEsi;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEax;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEbx;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEcx;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEdx;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEbp;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEip;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegCs;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_EFlags;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_RegEsp;
 [[OS2 API:DataType:ULONG|ULONG]] ctx_SegSs;
 } CONTEXTRECORD;
 
=== Fields ===
   
 ContextFlags Flags which control the contents of the context record. 
              Possible values are shown in the following list: 
              * [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]] SS:ESP, CS:EIP, EFLAGS and EBP 
              * [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]] EAX, EBX, ECX, EDX, ESI and EDI 
              * [[OS2 API:Constant:CONTEXT#CONTEXT_SEGMENTS|CONTEXT_SEGMENTS]] DS, ES, FS, and GS 
              * [[OS2 API:Constant:CONTEXT#CONTEXT_FLOATING_POINT|CONTEXT_FLOATING_POINT]] numeric coprocessor state
              * [[OS2 API:Constant:CONTEXT#CONTEXT_FULL|CONTEXT_FULL]] all the above.
               
              If the context record is used as an input parameter, then for each      
              portion of the context record controlled by a flag whose value is
              set, it is assumed that the portion of the context record contains
              valid context. If the context record is being used to modify a
              thread's context, then only that portion of the thread's context
              will be modified. 

              If the context record is used as an input/output parameter to
              capture the context of a thread, then only those portions of the
              thread's context corresponding to set flags will be returned.

 ctx_env[7]   This parameter is used only when ContextFlags is set to
              [[API:Constant:CONTEXT#CONTEXT_FLOATING_POINT|CONTEXT_FLOATING_POINT]].

 ctx_stack[8] This parameter is used only when ContextFlags is set to 
              [[API:Constant:CONTEXT#CONTEXT_FLOATING_POINT|CONTEXT_FLOATING_POINT]]. 
  
 ctx_SegGs    GS register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_SEGMENTS|CONTEXT_SEGMENTS]].

 ctx_SegFs    FS register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_SEGMENTS|CONTEXT_SEGMENTS]].

 ctx_SegEs    ES register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_SEGMENTS|CONTEXT_SEGMENTS]].

 ctx_SegDs    DS register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_SEGMENTS|CONTEXT_SEGMENTS]]. 
  
 ctx_RegEdi   EDI register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]].

 ctx_RegEsi   ESI register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]].

 ctx_RegEax   EAX register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]].

 ctx_RegEbx   EBX register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]].
   
 ctx_RegEcx   ECX register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]]. 
  
 ctx_RegEdx   EDX register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_INTEGER|CONTEXT_INTEGER]].

 ctx_RegEbp   EBP register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]].

 ctx_RegEip   EIP register.
              This parameter is used only when ContextFlags is set to
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]]. 
  
 ctx_SegCs    CS register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]].

 ctx_EFlags   EFLAGS register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]].

 ctx_RegEsp   ESP register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]].

 ctx_SegSs    SS register.
              This parameter is used only when ContextFlags is set to 
              [[OS2 API:Constant:CONTEXT#CONTEXT_CONTROL|CONTEXT_CONTROL]].

=== Comment ===

Note that only the register sets specified by ContextFlags contain valid data. Conversely, only registers specified in ContextFlags will be restored if an exception is handled.