From 4cbd3c3ea9e251eadd74e0971b0510fc05f95aa4 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Mon, 9 May 2011 13:28:19 -0700
Subject: [PATCH] detect closed descriptors on EINTR

We don't want to retry with the same FD if it somehow
got closed and reopened in a different thread.  We
could possibly have Errno::EBADF, too, but
rb_thread_io_blocking_region doesn't allow multiple
file descriptors...
---
 ext/io_splice/io_splice_ext.c | 50 ++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 15 deletions(-)

diff --git a/ext/io_splice/io_splice_ext.c b/ext/io_splice/io_splice_ext.c
index 4396fb0..1181797 100644
--- a/ext/io_splice/io_splice_ext.c
+++ b/ext/io_splice/io_splice_ext.c
@@ -54,6 +54,14 @@ static int my_fileno(VALUE io)
 		}
 	}
 }
+
+static int check_fileno(VALUE io)
+{
+	int saved_errno = errno;
+	int fd = my_fileno(io);
+	errno = saved_errno;
+	return fd;
+}
 #ifndef HAVE_RB_THREAD_BLOCKING_REGION
 /* partial emulation of the 1.9 rb_thread_blocking_region under 1.8 */
 #  include <rubysig.h>
@@ -92,12 +100,7 @@ rb_thread_blocking_region(
 
 static VALUE io_run(rb_blocking_function_t *fn, void *data)
 {
-	ssize_t n;
-retry:
-	n = (ssize_t)rb_thread_blocking_region(fn, data, RUBY_UBF_IO, 0);
-	if (n == -1 && errno == EINTR)
-		goto retry;
-	return (VALUE)n;
+	return rb_thread_blocking_region(fn, data, RUBY_UBF_IO, 0);
 }
 
 struct splice_args {
@@ -122,18 +125,23 @@ static long do_splice(int argc, VALUE *argv, unsigned dflags)
 	off_t i, o;
 	VALUE fd_in, off_in, fd_out, off_out, len, flags;
 	struct splice_args a;
+	long bytes;
 
 	rb_scan_args(argc, argv, "51",
 	             &fd_in, &off_in, &fd_out, &off_out, &len, &flags);
 
 	a.off_in = NIL_P(off_in) ? NULL : (i = NUM2OFFT(off_in), &i);
 	a.off_out = NIL_P(off_out) ? NULL : (o = NUM2OFFT(off_out), &o);
-	a.fd_in = my_fileno(fd_in);
-	a.fd_out = my_fileno(fd_out);
 	a.len = (size_t)NUM2ULONG(len);
 	a.flags = NIL_P(flags) ? dflags : NUM2UINT(flags) | dflags;
 
-	return (long)io_run(nogvl_splice, &a);
+	do {
+		a.fd_in = check_fileno(fd_in);
+		a.fd_out = check_fileno(fd_out);
+		bytes = (long)io_run(nogvl_splice, &a);
+	} while (bytes == -1 && errno == EINTR);
+
+	return bytes;
 }
 
 /*
@@ -235,14 +243,19 @@ static long do_tee(int argc, VALUE *argv, unsigned dflags)
 {
 	VALUE fd_in, fd_out, len, flags;
 	struct tee_args a;
+	long bytes;
 
 	rb_scan_args(argc, argv, "31", &fd_in, &fd_out, &len, &flags);
-	a.fd_in = my_fileno(fd_in);
-	a.fd_out = my_fileno(fd_out);
 	a.len = (size_t)NUM2ULONG(len);
 	a.flags = NIL_P(flags) ? dflags : NUM2UINT(flags) | dflags;
 
-	return (long)io_run(nogvl_tee, &a);
+	do {
+		a.fd_in = check_fileno(fd_in);
+		a.fd_out = check_fileno(fd_out);
+		bytes = (long)io_run(nogvl_tee, &a);
+	} while (bytes == -1 && errno == EINTR);
+
+	return bytes;
 }
 
 /*
@@ -431,10 +444,13 @@ static VALUE my_vmsplice(int argc, VALUE * argv, VALUE self)
 
 		if (n < 0) {
 			if (errno == EAGAIN) {
-				if (a.flags & SPLICE_F_NONBLOCK)
+				if (a.flags & SPLICE_F_NONBLOCK) {
 					rb_sys_fail("vmsplice");
-				else if (rb_io_wait_writable(a.fd))
-					continue;
+				} else {
+					a.fd = check_fileno(fd);
+					if (rb_io_wait_writable(a.fd))
+						continue;
+				}
 				/* fall through on error */
 			}
 			/*
@@ -444,6 +460,10 @@ static VALUE my_vmsplice(int argc, VALUE * argv, VALUE self)
 			 */
 			if (rv > 0)
 				break;
+			if (errno == EINTR) {
+				a.fd = check_fileno(fd);
+				continue;
+			}
 			rb_sys_fail("vmsplice");
 		}
 
-- 
2.11.4.GIT