
124 Introduction to Concurrency in Programming Languages
Listing 6.3: The use of an ALGOL collateral clause. Note the use of the
comma to separate the second and third statements.
X =1;
Y=X +1,
W=X -1;
Z=Y* X * W;
effects in statements occur in the sequence order as specified in the program
text with the result of the final statement being the result of the sequence. C
does not provide collateral clauses, even if it provides a similar comma-based
statement separator for some instances of statement sequences.
In many applications that use parallelism, the individual processes must
communicate with each other. Often there is some level of synchronization
necessary ...