- These functions manipulate signal mask stored in a _\bs_\bi_\bg_\bs_\be_\bt__\bt.
- They are provided as macros, but actual functions are avail-
- able if their names are undefined (with #undef _\bn_\ba_\bm_\be).
-
- The _\bs_\bi_\bg_\be_\bm_\bp_\bt_\by_\bs_\be_\bt function initializes a signal set to be
- empty. The _\bs_\bi_\bg_\bf_\bi_\bl_\bl_\bs_\be_\bt function initializes a signal set to
- contain all of the known signals. One of these routines
- must be used to initialize a signal set before its use by
- the other functions.
-
- The _\bs_\bi_\bg_\ba_\bd_\bd_\bs_\be_\bt function adds a specified signal _\bs_\bi_\bg_\bn_\bo to a
- signal set. The _\bs_\bi_\bg_\bd_\be_\bl_\bs_\be_\bt function deletes a specified sig-
- nal _\bs_\bi_\bg_\bn_\bo from a signal set.
-
- The _\bs_\bi_\bg_\bi_\bs_\bm_\be_\bm_\bb_\be_\br function tests whether a specified signal
- _\bs_\bi_\bg_\bn_\bo is contained in a signal set.
+ These functions manipulate signal sets stored in a _\bs_\bi_\bg_\bs_\be_\bt_\b__\bt. Either
+ s\bsi\big\bge\bem\bmp\bpt\bty\bys\bse\bet\bt() or s\bsi\big\bgf\bfi\bil\bll\bls\bse\bet\bt() must be called for every object of type
+ _\bs_\bi_\bg_\bs_\be_\bt_\b__\bt before any other use of the object.