Merge pull request #225 from jpco/less-slow

Reduce use of, and simplify, slow syscall handling.

Only use slow and slowlabel where they're needed, and remove the redundant 'interrupted' variable.

Author: jpco

es.h

@@ -282,11 +282,9 @@ extern void *ealloc(size_t n);
 extern void *erealloc(void *p, size_t n);
 extern void efree(void *p);
 extern void ewrite(int fd, const char *s, size_t n);
-extern long eread(int fd, char *buf, size_t n);
 extern Boolean isabsolute(char *path);
 extern Boolean streq2(const char *s, const char *t1, const char *t2);
 
-
 /* input.c */
 
 extern char *prompt, *prompt2;
@@ -365,7 +363,7 @@ extern void setsigeffects(const Sigeffect effects[]);
 extern void getsigeffects(Sigeffect effects[]);
 extern List *mksiglist(void);
 extern void initsignals(Boolean interactive, Boolean allowdumps);
-extern Atomic slow, interrupted;
+extern Atomic slow;
 extern jmp_buf slowlabel;
 extern Boolean sigint_newline;
 extern void sigchk(void);

input.c

@@ -150,12 +150,9 @@ static char *callreadline(char *prompt0) {
 	}
 	if (RL_ISSTATE(RL_STATE_INITIALIZED))
 		rl_reset_screen_size();
-	interrupted = FALSE;
 	if (!setjmp(slowlabel)) {
 		slow = TRUE;
-		r = interrupted ? NULL : readline(prompt);
-		if (interrupted)
-			errno = EINTR;
+		r = readline(prompt);
 	} else {
 		r = NULL;
 		errno = EINTR;
@@ -196,7 +193,7 @@ static int fdfill(Input *in) {
 	} else
 #endif
 	do {
-		nread = eread(in->fd, (char *) in->bufbegin, in->buflen);
+		nread = read(in->fd, (char *) in->bufbegin, in->buflen);
 		SIGCHK();
 	} while (nread == -1 && errno == EINTR);
 

prim-io.c

@@ -365,7 +365,7 @@ static List *bqinput(const char *sep, int fd) {
 
 restart:
 	/* avoid SIGCHK()ing in here so we don't abandon our child process */
-	while ((n = eread(fd, in, sizeof in)) > 0)
+	while ((n = read(fd, in, sizeof in)) > 0)
 		splitstring(in, n, FALSE);
 	if (n == -1) {
 		if (errno == EINTR)
@@ -418,7 +418,7 @@ static int read1(int fd) {
 	int nread;
 	unsigned char buf;
 	do {
-		nread = eread(fd, (char *) &buf, 1);
+		nread = read(fd, (char *) &buf, 1);
 		SIGCHK();
 	} while (nread == -1 && errno == EINTR);
 	if (nread == -1)

signal.c

@@ -7,14 +7,19 @@ typedef void (*Sighandler)(int);
 
 Boolean sigint_newline = TRUE;
 
-jmp_buf slowlabel;
-Atomic slow = FALSE;
-Atomic interrupted = FALSE;
 static Atomic sigcount;
 static Atomic caught[NSIG];
 static Sigeffect sigeffect[NSIG];
 static Sighandler handler_in[NSIG];
 
+/*
+ * these variables are for the purpose of forcing a "return" from library or
+ * system calls when a signal is received, since some of them don't do that
+ * themselves.
+ */
+jmp_buf slowlabel;
+Atomic slow = FALSE;
+
 #if HAVE_SIGACTION
 #ifndef	SA_NOCLDSTOP
 #define	SA_NOCLDSTOP	0
@@ -79,7 +84,6 @@ static void catcher(int sig) {
 		caught[sig] = TRUE;
 		++sigcount;
 	}
-	interrupted = TRUE;
 	if (slow)
 		longjmp(slowlabel, 1);
 }

util.c

@@ -98,35 +98,7 @@ extern void ewrite(int fd, const char *buf, size_t n) {
 	volatile long i, remain;
 	const char *volatile bufp = buf;
 	for (i = 0, remain = n; remain > 0; bufp += i, remain -= i) {
-		interrupted = FALSE;
-		if (!setjmp(slowlabel)) {
-			slow = TRUE;
-			if (interrupted)
-				break;
-			else if ((i = write(fd, bufp, remain)) <= 0)
-				break; /* abort silently on errors in write() */
-		} else
-			break;
-		slow = FALSE;
+		if ((i = write(fd, bufp, remain)) < 0 && errno != EINTR)
+			break; /* abort silently on errors in write() */
 	}
-	slow = FALSE;
-}
-
-extern long eread(int fd, char *buf, size_t n) {
-	long r;
-	interrupted = FALSE;
-	if (!setjmp(slowlabel)) {
-		slow = TRUE;
-		if (!interrupted)
-			r = read(fd, buf, n);
-		else
-			r = -2;
-	} else
-		r = -2;
-	slow = FALSE;
-	if (r == -2) {
-		errno = EINTR;
-		r = -1;
-	}
-	return r;
 }