💾 Archived View for thrig.me › blog › 2022 › 12 › 11 › vi.patch captured on 2023-01-29 at 03:39:47.
-=-=-=-=-=-=-
diff --git usr.bin/vi/cl/cl_main.c usr.bin/vi/cl/cl_main.c index 33614c99594..f87a04cad8b 100644 --- usr.bin/vi/cl/cl_main.c +++ usr.bin/vi/cl/cl_main.c @@ -54,7 +54,7 @@ main(int argc, char *argv[]) CL_PRIVATE *clp; GS *gp; size_t rows, cols; - int rval; + int flags, oflags, rval; char *ttype; /* Create and initialize the global structure. */ @@ -89,6 +89,14 @@ main(int argc, char *argv[]) /* Ex wants stdout to be buffered. */ (void)setvbuf(stdout, NULL, _IOFBF, 0); + /* Ensure blocking I/O to avoid 100% CPU on EAGAIN */ + if ((flags = fcntl(STDIN_FILENO, F_GETFL, 0)) == -1) + exit (1); + oflags = flags; + flags &= ~O_NONBLOCK; + if (fcntl(STDIN_FILENO, F_SETFL, flags) == -1) + exit (1); + /* Start catching signals. */ if (sig_init(gp, NULL)) exit (1); @@ -102,6 +110,9 @@ main(int argc, char *argv[]) /* Clean up the terminal. */ (void)cl_quit(gp); + /* Restore flags */ + fcntl(STDIN_FILENO, F_SETFL, oflags); + /* * XXX * Reset the O_MESG option.