bc: switch to SA_RESTART signal handling

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-12-04 21:21:32 +01:00
parent d70d4a0235
commit 17c5472c5a

View File

@ -7121,7 +7121,23 @@ static BcStatus bc_vm_run(int argc, char *argv[],
if (G.ttyin) {
#if ENABLE_FEATURE_BC_SIGNALS
signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
// With SA_RESTART, most system calls will restart
// (IOW: they won't fail with EINTR).
// In particular, this means ^C won't cause
// stdout to get into "error state" if SIGINT hits
// within write() syscall.
// The downside is that ^C while line input is taken
// will only be handled after [Enter] since read()
// from stdin is not interrupted by ^C either,
// it restarts, thus fgetc() does not return on ^C.
signal_SA_RESTART_empty_mask(SIGINT, record_signo);
// Without SA_RESTART, this exhibits a bug:
// "while (1) print 1" and try ^C-ing it.
// Intermittently, instead of returning to input line,
// you'll get "output error: Interrupted system call"
// and exit.
//signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
#endif
if (!(option_mask32 & BC_FLAG_Q))
bc_vm_info();