BLOCK The! $BLOCK control command will allocate blocking buffers from unused memory space as requested
buffers. Thus, if two operational labels were to use a block-ing buffer area at different times, the first might release the area for use by the second. Only one of the two labels would be required on the! $BLOCK command.
M:LOAD checks which of the operational labels are assigned to block files atrun time to make the pool allocation. If such an allocation overflows the available memory space (between the end of the longest path and COMMON), the execution aborts. However, the user may define his own blocking buffer by specific calls to M:OPEN. Such an area should be in a reserved area of his own path. He should not use the dynamically allocated pool area, and blocking buf-fers may not be allocated in temporary stacks. Only one the user may provide a count(c) of blocking buffers required.
LIB The! $UB control command specifies a new default
library must be oneofthe following EBCDIC codes.
Code Library
B Basic
E Extended
x,[yJ specify the order of search. The x and y pa-rameters are either of the following EBCDIC codes.
Code Library ni-tions and their values including the libraries and permanent symbol table are output. Double definitions, and definition declarations that were not given a value are flagged D and U, respectively. Unsatisfied primary references are flagged with UP, unsatisfied secondary references with US.
The format of the command is
If relevant, information concerning the Public Library is also mapped.
TCB The! $TCB control command indicates (for a fore-ground task only) that the Overlay Loader must create a TCB and reserve a PSD location, and must generate a call to RBM routine M:SAVE. M:FSAVE will be called if the set multiple precision mode exists. In addition, information to initialize the TCB at run time will be passed in the file foreground tasks only. Multiple! $TCB commands may be used internal to the root program. Each !$TCB command of the created TCB (see "Real-Time Programming, Chapter 6).
Control Command Repertoire 81
temp defines the size of the temporary stack to be reserved for a TCB other than the initial TCB.
The Overlay Loader will handle specific and default cases of program execution and TCB initialization within the framework of the followi ng restri ctions: optionally, trigger the task using information in words 1 and 2 of the TCB. execution location plus the "temp" value specified on the ! $ROOT command. M:LOAD will not initialize any subtask.
The user exits with either a call to the RBM routine M:EXIT or by a standard exit procedure.
Public Library routines and Monitor service routines called by the user program will require temporary storage areas that are dynamically allocated at execution time. These temporary storage areas must be a IIocated in a fixed storage
82 Control Command Repertoire
For more information On initialization and structure of TCBs, see Chapter 6.
there are no file-positioning control commands recognized
INCLUDE The! $INCLUDE control command specifies external definitions in those library modules that are to be
EXCLUDE The! $EXCLUDE control command inhibits library search and linkage for the named definition(s) even of several defi nitiol1s associated with a specifi c library pro-gram, then excluding the one def is sufficient to forestall loading of its associated library module.
MD The! $MD (modify) control command is used to restrictions set forth in IIControl Command Format". Note that it is not possible to modify a I ibrary module by use of an ! $MD control command.
Control Command Repertoire 83
RES The! $RES control command allows the user to
1 $LCOM block,size [,block,size] ... ['block,sizeJ
where through the appl ication of the! $EXCLUDE command. The Loader wi II attempt to satisfy all references present at a contiguously from the operational label oplb.
84 Control Command Repertoire
The following rules should be observed in defining segments the ! $INCLUDE command, other often-used library routines can be loaded with the root where they will reserve areas which will consequently consume space duri ng Loader processing.
At execution time an expl icit call to RBM routi ne M:SEG LD with the segment identifier number and the ADRL OV:LOAD causes the readi ng of that segment into memory from the OV file. Thus, any segment may, by an explicit cail, cause any other segment to be loaded for execution.
PUBLIB The! $PUBUB control command indicates that the Overlay Loader is to create a Public Library using command) for their temporary storage space. To conserve core space when formi ng the Publ i c Library, the Loader
area. The new LIBSYM is incompatible with the Public Library currently in core. All files are closed and nor-mal termination through M:TERM takes place. The new Public Library is then loaded into core by rebooting the RBM. The format of the command is
! $PUBLIB library-mode[,oplb,n]
where
mode must be one of the following EBCDIC codes:
Code Mode
B Basic
E Extended
M Main
A new ! $PUBLIB control command must be pro-vided each time mode is to be changed.
oplb, n specifies that n modules are to be loaded contiguously from the operational label oplb.
!$LD, !$LB, !$INCLUDE, and !$MD commands are hon-ored when using! $PUBLIB in the same manner as for the
! $SEG command. ! $ROOT, ! $TCB, and ! $SEG commands may not be used in conjunction with the! $PUBLIB command.
END The! $END command is treated exactly like an
! EOD command. It should be used in place of ! EOD when-ever multistep job stacks are to be prestored on a RAD file.
The Utility COpy routine will not interpret this com-mand as end-of-file (EOF). The format of the comcom-mand is