1 files changed, 210 insertions, 0 deletions
diff --git a/ext/io/nonblock/nonblock.c b/ext/io/nonblock/nonblock.c
new file mode 100644
index 0000000000..cd40ea3335
--- /dev/null
+++ b/ext/io/nonblock/nonblock.c
@@ -0,0 +1,210 @@
+/**********************************************************************
+
+  io/nonblock.c -
+
+  $Author$
+  created at: Tue Jul 14 21:53:18 2009
+
+  All the files in this distribution are covered under the Ruby's
+  license (see the file COPYING).
+
+**********************************************************************/
+
+#include "ruby.h"
+#include "ruby/io.h"
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+
+#ifndef HAVE_RB_IO_DESCRIPTOR
+static int
+io_descriptor_fallback(VALUE io)
+{
+    rb_io_t *fptr;
+    GetOpenFile(io, fptr);
+    return fptr->fd;
+}
+#define rb_io_descriptor io_descriptor_fallback
+#endif
+
+#ifdef F_GETFL
+static int
+get_fcntl_flags(int fd)
+{
+    int f = fcntl(fd, F_GETFL);
+    if (f == -1) rb_sys_fail(0);
+    return f;
+}
+#else
+#define get_fcntl_flags(fd) ((void)(fd), 0)
+#endif
+
+#ifdef F_GETFL
+/*
+ * call-seq:
+ *   io.nonblock? -> boolean
+ *
+ * Returns +true+ if an IO object is in non-blocking mode.
+ */
+static VALUE
+rb_io_nonblock_p(VALUE io)
+{
+    if (get_fcntl_flags(rb_io_descriptor(io)) & O_NONBLOCK)
+        return Qtrue;
+    return Qfalse;
+}
+#else
+#define rb_io_nonblock_p rb_f_notimplement
+#endif
+
+#ifdef F_SETFL
+static void
+set_fcntl_flags(int fd, int f)
+{
+    if (fcntl(fd, F_SETFL, f) == -1)
+	rb_sys_fail(0);
+}
+
+#ifndef RUBY_IO_NONBLOCK_METHODS
+
+static int
+io_nonblock_set(int fd, int f, int nb)
+{
+    if (nb) {
+	if ((f & O_NONBLOCK) != 0)
+	    return 0;
+	f |= O_NONBLOCK;
+    }
+    else {
+	if ((f & O_NONBLOCK) == 0)
+	    return 0;
+	f &= ~O_NONBLOCK;
+    }
+    set_fcntl_flags(fd, f);
+    return 1;
+}
+
+/*
+ * call-seq:
+ *   io.nonblock = boolean -> boolean
+ *
+ * Enables non-blocking mode on a stream when set to
+ * +true+, and blocking mode when set to +false+.
+ *
+ * This method set or clear O_NONBLOCK flag for the file descriptor
+ * in <em>ios</em>.
+ *
+ * The behavior of most IO methods is not affected by this flag
+ * because they retry system calls to complete their task
+ * after EAGAIN and partial read/write.
+ * (An exception is IO#syswrite which doesn't retry.)
+ *
+ * This method can be used to clear non-blocking mode of standard I/O.
+ * Since nonblocking methods (read_nonblock, etc.) set non-blocking mode but
+ * they doesn't clear it, this method is usable as follows.
+ *
+ *   END { STDOUT.nonblock = false }
+ *   STDOUT.write_nonblock("foo")
+ *
+ * Since the flag is shared across processes and
+ * many non-Ruby commands doesn't expect standard I/O with non-blocking mode,
+ * it would be safe to clear the flag before Ruby program exits.
+ *
+ * For example following Ruby program leaves STDIN/STDOUT/STDER non-blocking mode.
+ * (STDIN, STDOUT and STDERR are connected to a terminal.
+ * So making one of them nonblocking-mode effects other two.)
+ * Thus cat command try to read from standard input and
+ * it causes "Resource temporarily unavailable" error (EAGAIN).
+ *
+ *   % ruby -e '
+ *   STDOUT.write_nonblock("foo\n")'; cat
+ *   foo
+ *   cat: -: Resource temporarily unavailable
+ *
+ * Clearing the flag makes the behavior of cat command normal.
+ * (cat command waits input from standard input.)
+ *
+ *   % ruby -rio/nonblock -e '
+ *   END { STDOUT.nonblock = false }
+ *   STDOUT.write_nonblock("foo")
+ *   '; cat
+ *   foo
+ *
+ */
+static VALUE
+rb_io_nonblock_set(VALUE self, VALUE value)
+{
+    if (RTEST(value)) {
+        rb_io_t *fptr;
+        GetOpenFile(self, fptr);
+        rb_io_set_nonblock(fptr);
+    }
+    else {
+        int descriptor = rb_io_descriptor(self);
+        io_nonblock_set(descriptor, get_fcntl_flags(descriptor), RTEST(value));
+    }
+
+    return self;
+}
+
+#endif /* RUBY_IO_NONBLOCK_METHODS */
+
+static VALUE
+io_nonblock_restore(VALUE arg)
+{
+    int *restore = (int *)arg;
+    set_fcntl_flags(restore[0], restore[1]);
+    return Qnil;
+}
+
+/*
+ * call-seq:
+ *   io.nonblock {|io| } -> object
+ *   io.nonblock(boolean) {|io| } -> object
+ *
+ * Yields +self+ in non-blocking mode.
+ *
+ * When +false+ is given as an argument, +self+ is yielded in blocking mode.
+ * The original mode is restored after the block is executed.
+ */
+static VALUE
+rb_io_nonblock_block(int argc, VALUE *argv, VALUE self)
+{
+    int nb = 1;
+
+    int descriptor = rb_io_descriptor(self);
+
+    if (argc > 0) {
+        VALUE v;
+        rb_scan_args(argc, argv, "01", &v);
+        nb = RTEST(v);
+    }
+
+    int current_flags = get_fcntl_flags(descriptor);
+    int restore[2] = {descriptor, current_flags};
+
+    if (!io_nonblock_set(descriptor, current_flags, nb))
+        return rb_yield(self);
+
+    return rb_ensure(rb_yield, self, io_nonblock_restore, (VALUE)restore);
+}
+#else
+#define rb_io_nonblock_set rb_f_notimplement
+#define rb_io_nonblock_block rb_f_notimplement
+#endif
+
+void
+Init_nonblock(void)
+{
+#ifdef HAVE_RB_EXT_RACTOR_SAFE
+    rb_ext_ractor_safe(true);
+#endif
+
+#ifndef RUBY_IO_NONBLOCK_METHODS
+    rb_define_method(rb_cIO, "nonblock?", rb_io_nonblock_p, 0);
+    rb_define_method(rb_cIO, "nonblock=", rb_io_nonblock_set, 1);
+#endif
+
+    rb_define_method(rb_cIO, "nonblock", rb_io_nonblock_block, -1);
+}