DosFlagProcess

Bindings:  C, MASM 

This call allows one process to set an external event flag for another. 

 DosFlagProcess     (ProcessID, ActionCode, Flagnum, Flagarg) 
 

 ProcessID (PID) - input 
    ID of the process or root process of the process tree, who is to 
    receive notification that the flag event has occurred. 

 ActionCode (USHORT) - input 
    Indicates who is to receive notification that the flag event has 
    occurred. 

    Value     Definition 
    0         The indicated process and all its descendant processes are 
              flagged.  (Detached processes cannot be flagged.) The 
              indicated process must be the current process or one it has 
              created as a non-detached process.  If the indicated process 
              terminates, its descendants are still flagged. 
    1         Only the indicated process is flagged.  Any process can be 
              specified. 

 Flagnum (USHORT) - input 
    Number of the flag event whose occurrence is to be signalled as shown 
    below: 

    Value     Definition 
    0         Flag A 
    1         Flag B 
    2         Flag C. 

 Flagarg (USHORT) - input 
    An argument passed to indicated processes. 

 rc (USHORT) - return 
    Return code descriptions are: 

    0         NO_ERROR 
    1         ERROR_INVALID_FUNCTION 
    156       ERROR_SIGNAL_REFUSED 
    186       ERROR_INVALID_FLAG_NUMBER 
    303       ERROR_INVALID_PROCID 
 
 Remarks 

 A process issues DosFlagProcess to set one of three user-defined flags 
 available to the process. The meaning of the flag is defined by the flag 
 user - the process that receives the signal generated by the OS/2 signal 
 mechanism upon the setting of the flag. 

 When the flag user is signaled, its reaction to the signal depends on 
 values it has specified with DosSetSigHandler. For example, it can 
 respond by giving control to a signal handler it has registered with 
 DosSetSigHandler for the signal that corresponds to the user flag (SIGPFA 
 corresponds to Flag A, and so on). Or, the flag user can ignore the 
 signal and return an error code to the flagger. 

 If no action is specified with DosSetSigHandler by a process for a user 
 flag, the default is to ignore the signal.