* io.c (io_read_nonblock): support non-blocking reads without raising

  exceptions. As in: `io.read_nonblock(size, exception: false)`
  [ruby-core:38666] [Feature #5138]
* ext/openssl/ossl_ssl.c (ossl_ssl_read_internal): ditto
* ext/stringio/stringio.c (strio_sysread): ditto
* io.c (rb_io_write_nonblock): support non-blocking writes without
  raising an exception.
* ext/openssl/ossl_ssl.c (ossl_ssl_write_internal): ditto
* test/openssl/test_pair.rb (class OpenSSL): tests
* test/ruby/test_io.rb (class TestIO): ditto
* test/socket/test_nonblock.rb (class TestSocketNonblock): ditto
* test/stringio/test_stringio.rb (class TestStringIO): ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42695 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 89 insertions, 15 deletions

diff --git a/ext/openssl/lib/openssl/buffering.rb b/ext/openssl/lib/openssl/buffering.rb
index 51bc968e3a..e40dfee667 100644
--- a/ext/openssl/lib/openssl/buffering.rb
+++ b/ext/openssl/lib/openssl/buffering.rb
@@ -161,7 +161,7 @@ module OpenSSL::Buffering
   # when the peer requests a new TLS/SSL handshake.  See openssl the FAQ for
   # more details.  http://www.openssl.org/support/faq.html
 
-  def read_nonblock(maxlen, buf=nil)
+  def read_nonblock(maxlen, buf=nil, exception: true)
     if maxlen == 0
       if buf
         buf.clear
@@ -171,7 +171,7 @@ module OpenSSL::Buffering
       end
     end
     if @rbuffer.empty?
-      return sysread_nonblock(maxlen, buf)
+      return sysread_nonblock(maxlen, buf, exception: exception)
     end
     ret = consume_rbuff(maxlen)
     if buf
@@ -370,9 +370,9 @@ module OpenSSL::Buffering
   # is when the peer requests a new TLS/SSL handshake.  See the openssl FAQ
   # for more details.  http://www.openssl.org/support/faq.html
 
-  def write_nonblock(s)
+  def write_nonblock(s, exception: true)
     flush
-    syswrite_nonblock(s)
+    syswrite_nonblock(s, exception: exception)
   end
 
   ##
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index fde5ac4fe5..ccbb793cd6 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -103,6 +103,8 @@ static const char *ossl_ssl_attrs[] = {
 
 ID ID_callback_state;
 
+static VALUE sym_exception;
+
 /*
  * SSLContext class
  */
@@ -1373,10 +1375,16 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
 {
     SSL *ssl;
     int ilen, nread = 0;
+    int no_exception = 0;
     VALUE len, str;
     rb_io_t *fptr;
+    VALUE opts = Qnil;
+
+    rb_scan_args(argc, argv, "11:", &len, &str, &opts);
+
+    if (!NIL_P(opts) && Qfalse == rb_hash_aref(opts, sym_exception))
+	no_exception = 1;
 
-    rb_scan_args(argc, argv, "11", &len, &str);
     ilen = NUM2INT(len);
     if(NIL_P(str)) str = rb_str_new(0, ilen);
     else{
@@ -1397,17 +1405,23 @@ ossl_ssl_read_internal(int argc, VALUE *argv, VALUE self, int nonblock)
 	    case SSL_ERROR_NONE:
 		goto end;
 	    case SSL_ERROR_ZERO_RETURN:
+		if (no_exception) { return Qnil; }
 		rb_eof_error();
 	    case SSL_ERROR_WANT_WRITE:
+		if (no_exception) { return ID2SYM(rb_intern("wait_writable")); }
                 write_would_block(nonblock);
                 rb_io_wait_writable(FPTR_TO_FD(fptr));
                 continue;
 	    case SSL_ERROR_WANT_READ:
+		if (no_exception) { return ID2SYM(rb_intern("wait_readable")); }
                 read_would_block(nonblock);
                 rb_io_wait_readable(FPTR_TO_FD(fptr));
 		continue;
 	    case SSL_ERROR_SYSCALL:
-		if(ERR_peek_error() == 0 && nread == 0) rb_eof_error();
+		if(ERR_peek_error() == 0 && nread == 0) {
+		    if (no_exception) { return Qnil; }
+		    rb_eof_error();
+		}
 		rb_sys_fail(0);
 	    default:
 		ossl_raise(eSSLError, "SSL_read");
@@ -1445,9 +1459,11 @@ ossl_ssl_read(int argc, VALUE *argv, VALUE self)
  * call-seq:
  *    ssl.sysread_nonblock(length) => string
  *    ssl.sysread_nonblock(length, buffer) => buffer
+ *    ssl.sysread_nonblock(length[, buffer [, opts]) => buffer
  *
  * A non-blocking version of #sysread.  Raises an SSLError if reading would
- * block.
+ * block.  If "exception: false" is passed, this method returns a symbol of
+ * :wait_writable, :wait_writable, or nil, rather than raising an exception.
  *
  * Reads +length+ bytes from the SSL connection.  If a pre-allocated +buffer+
  * is provided the data will be written into it.
@@ -1459,7 +1475,7 @@ ossl_ssl_read_nonblock(int argc, VALUE *argv, VALUE self)
 }
 
 static VALUE
-ossl_ssl_write_internal(VALUE self, VALUE str, int nonblock)
+ossl_ssl_write_internal(VALUE self, VALUE str, int nonblock, int no_exception)
 {
     SSL *ssl;
     int nwrite = 0;
@@ -1476,10 +1492,12 @@ ossl_ssl_write_internal(VALUE self, VALUE str, int nonblock)
 	    case SSL_ERROR_NONE:
 		goto end;
 	    case SSL_ERROR_WANT_WRITE:
+		if (no_exception) { return ID2SYM(rb_intern("wait_writable")); }
                 write_would_block(nonblock);
                 rb_io_wait_writable(FPTR_TO_FD(fptr));
                 continue;
 	    case SSL_ERROR_WANT_READ:
+		if (no_exception) { return ID2SYM(rb_intern("wait_readable")); }
                 read_would_block(nonblock);
                 rb_io_wait_readable(FPTR_TO_FD(fptr));
                 continue;
@@ -1509,7 +1527,7 @@ ossl_ssl_write_internal(VALUE self, VALUE str, int nonblock)
 static VALUE
 ossl_ssl_write(VALUE self, VALUE str)
 {
-    return ossl_ssl_write_internal(self, str, 0);
+    return ossl_ssl_write_internal(self, str, 0, 0);
 }
 
 /*
@@ -1520,9 +1538,18 @@ ossl_ssl_write(VALUE self, VALUE str)
  * SSLError if writing would block.
  */
 static VALUE
-ossl_ssl_write_nonblock(VALUE self, VALUE str)
+ossl_ssl_write_nonblock(int argc, VALUE *argv, VALUE self)
 {
-    return ossl_ssl_write_internal(self, str, 1);
+    VALUE str;
+    VALUE opts = Qnil;
+    int no_exception = 0;
+
+    rb_scan_args(argc, argv, "1:", &str, &opts);
+
+    if (!NIL_P(opts) && Qfalse == rb_hash_aref(opts, sym_exception))
+	no_exception = 1;
+
+    return ossl_ssl_write_internal(self, str, 1, no_exception);
 }
 
 /*
@@ -2168,7 +2195,7 @@ Init_ossl_ssl()
     rb_define_method(cSSLSocket, "sysread",    ossl_ssl_read, -1);
     rb_define_private_method(cSSLSocket, "sysread_nonblock",    ossl_ssl_read_nonblock, -1);
     rb_define_method(cSSLSocket, "syswrite",   ossl_ssl_write, 1);
-    rb_define_private_method(cSSLSocket, "syswrite_nonblock",    ossl_ssl_write_nonblock, 1);
+    rb_define_private_method(cSSLSocket, "syswrite_nonblock",    ossl_ssl_write_nonblock, -1);
     rb_define_method(cSSLSocket, "sysclose",   ossl_ssl_close, 0);
     rb_define_method(cSSLSocket, "cert",       ossl_ssl_get_cert, 0);
     rb_define_method(cSSLSocket, "peer_cert",  ossl_ssl_get_peer_cert, 0);
@@ -2239,4 +2266,6 @@ Init_ossl_ssl()
     ossl_ssl_def_const(OP_PKCS1_CHECK_2);
     ossl_ssl_def_const(OP_NETSCAPE_CA_DN_BUG);
     ossl_ssl_def_const(OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG);
+
+    sym_exception = ID2SYM(rb_intern("exception"));
 }
diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index ef3df832b8..5c2c64ca03 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -119,6 +119,8 @@ typedef char strio_flags_check[(STRIO_READABLE/FMODE_READABLE == STRIO_WRITABLE/
 #define READABLE(strio) STRIO_MODE_SET_P(strio, READABLE)
 #define WRITABLE(strio) STRIO_MODE_SET_P(strio, WRITABLE)
 
+static VALUE sym_exception;
+
 static struct StringIO*
 readable(VALUE strio)
 {
@@ -1327,7 +1329,6 @@ strio_read(int argc, VALUE *argv, VALUE self)
  * call-seq:
  *   strio.sysread(integer[, outbuf])    -> string
  *   strio.readpartial(integer[, outbuf])    -> string
- *   strio.read_nonblock(integer[, outbuf])    -> string
  *
  * Similar to #read, but raises +EOFError+ at end of string instead of
  * returning +nil+, as well as IO#sysread does.
@@ -1342,8 +1343,50 @@ strio_sysread(int argc, VALUE *argv, VALUE self)
     return val;
 }
 
+/*
+ * call-seq:
+ *   strio.read_nonblock(integer[, outbuf [, opts]])    -> string
+ *
+ * Similar to #read, but raises +EOFError+ at end of string unless the
+ * +exception: false+ option is passed in.
+ */
+static VALUE
+strio_read_nonblock(int argc, VALUE *argv, VALUE self)
+{
+    VALUE opts = Qnil;
+    int no_exception = 0;
+
+    rb_scan_args(argc, argv, "11:", NULL, NULL, &opts);
+
+    if (!NIL_P(opts)) {
+	argc--;
+
+	if (Qfalse == rb_hash_aref(opts, sym_exception))
+	    no_exception = 1;
+    }
+
+    VALUE val = strio_read(argc, argv, self);
+    if (NIL_P(val)) {
+	if (no_exception)
+	    return Qnil;
+	else
+	    rb_eof_error();
+    }
+
+    return val;
+}
+
 #define strio_syswrite rb_io_write
 
+static VALUE
+strio_syswrite_nonblock(int argc, VALUE *argv, VALUE self)
+{
+    VALUE str;
+
+    rb_scan_args(argc, argv, "10:", &str, NULL);
+    return strio_syswrite(self, str);
+}
+
 #define strio_isatty strio_false
 
 #define strio_pid strio_nil
@@ -1542,7 +1585,7 @@ Init_stringio()
 	rb_define_method(mReadable, "readline", strio_readline, -1);
 	rb_define_method(mReadable, "sysread", strio_sysread, -1);
 	rb_define_method(mReadable, "readpartial", strio_sysread, -1);
-	rb_define_method(mReadable, "read_nonblock", strio_sysread, -1);
+	rb_define_method(mReadable, "read_nonblock", strio_read_nonblock, -1);
 	rb_include_module(StringIO, mReadable);
     }
     {
@@ -1552,7 +1595,9 @@ Init_stringio()
 	rb_define_method(mWritable, "printf", strio_printf, -1);
 	rb_define_method(mWritable, "puts", strio_puts, -1);
 	rb_define_method(mWritable, "syswrite", strio_syswrite, 1);
-	rb_define_method(mWritable, "write_nonblock", strio_syswrite, 1);
+	rb_define_method(mWritable, "write_nonblock", strio_syswrite_nonblock, -1);
 	rb_include_module(StringIO, mWritable);
     }
+
+    sym_exception = ID2SYM(rb_intern("exception"));
 }