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include vmm.inc
 
mov     esi, CritSecCallback    ; points to callback procedure
mov     edx, RefData            ; points to data to pass to callback
VMMcall Call_When_Not_Critical
 
The Call_When_Not_Critical service installs a critical-section callback
procedure. The system calls this procedure whenever a virtual device
releases the critical section.
 
Parameter        Description
────────────────────────────────────────────────────────────────────────────
 
CritSecCallback  Points to the callback procedure to install. See the
                 Comments section for more information about the procedure.
 
RefData          Points to reference data to pass to the callback
                 procedure.
 
Return Value
 
This service has no return value.
 
Comments
 
The system does not execute the callback until the current virtual machine's
execution priority is less than the Critical_Section_Boost value even if the
current virtual machine is not in a critical section. This allows a virtual
device to release the critical section and process any simulated interrupts
before the system calls the callback procedure.
 
Virtual devices can install any number of callback procedures, but the
system calls only the most recent procedure on the list when the critical
section is released. The system removes the callback procedure from the list
as it calls the procedure.
 
The system calls the callback procedure as follows:
 
mov     ebx, VM                 ; current VM handle
mov     edx, OFFSET32 RefData   ; points to reference data
mov     ebp, OFFSET32 crs       ; points to a Client_Reg_Struc structure
call    [CritSecCallback]
 
The VM parameter specifies a handle identifying the current virtual machine,
RefData points to reference data from the virtual device that installed the
callback, and the csr parameter points to a Client_Reg_Struc structure
containing the registers of the current virtual machine.
 
The callback procedure can carry out any operation and can modify EAX, EBX,
ECX, EDX, ESI, EDI, and Flags.
 
It is more convenient to use the Call_Priority_VM_Event service than to call
this service directly.
 
Uses
 
Flags
 
See Also
 
Call_When_Idle, Call_When_Task_Switched
 
 
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