You should avoid using facilities that cause operating
system waits. All CICS® activity stops when one of these waits occurs, and
all transactions suffer response delays. The chief sources of such waits are:
Those COBOL, C, C++, and PL/I language facilities that you should
not use in CICS programs and for which CICS generally provides alternative
facilities. For guidance information about the language restrictions, see Programming in COBOL, Programming in C and C++, and Programming in PL/I.
SVCs and assembler language macros that invoke operating system services,
such as write-to-operator (WTO).