7 Using the Null Version of CRL

This section contains information relevant to building and using the null version of CRL.

The null CRL implementation is provided to allow sequential timings of CRL applications to be obtained without any overhead due to CRL. It can be used both on a single processor of a parallel system (e.g., CM-5, Alewife) on on uniprocessor systems (e.g., desktop workstations).

7.1 Building the Null Version of CRL

To build the null version of CRL 1.0:

1. Obtain a copy of the CRL 1.0 distribution (crl-1.0.tar.gz). This can be accomplished via links from the CRL World Wide Web page (http://www.pdos.lcs.mit.edu/crl/) or via anonymous ftp from cag.lcs.mit.edu in pub/crl.

2. Make a copy of crl-1.0.tar.gz in the directory where you want to install CRL 1.0; cd to that directory.

3. The CRL 1.0 tar file is compressed using gzip (thus the .gz extension). Uncompress the tar file using gunzip:

    unix% gunzip crl-1.0.tar.gz
   

   This will produce an uncompressed version of crl-1.0.tar.gz named crl-1.0.tar (and will also remove the compressed version).

4. Untar the distribution using tar xf:

    unix% tar xf crl-1.0.tar
   

   This will create a subdirectory of the current working directory called crl-1.0 and unpack the CRL 1.0 distribution into it.

5. cd into the CRL 1.0 null directory:

    unix% cd crl-1.0/null
   

   This directory contains the sources for the null version of the CRL library.

6. Use the make utility and the supplied Makefile.null file to build the CRL 1.0 object file (libcrl.o) for the null version of CRL:

    unix% make -f Makefile.null
   

   Once this completes, you are done building CRL. Applications intended for use with the null version of CRL should be linked against the resulting object file (libcrl.o).

To build and run the example application shown in Appendix A on a desktop workstation:

1. cd to the apps/example subdirectory of the top-level CRL 1.0 directory (crl-1.0). If you have just finished following the directions given above for building CRL, this would be accomplished by something like:

    unix% cd ../apps/example
   

2. Use the make utility and the supplied Makefile.null file to compile the application and link it against the necessary object files (e.g., libcrl.o).

    unix% make -f Makefile.null
   

3. Run the example application with no arguments

    unix% example
   

Applications in the other subdirectories of crl-1.0/apps can be compiled and run in a similar manner.

7.2 Platform-Specific Issues

The directions given above are known to work on Sun SPARCstations running SunOS 4.1.3; we expect that little or no change would be necessary for use with other hardware/software combinations.