Merge pull request #111 from jhawthorn/close_to_shutdown

Replace trilogy_sock_discard and shutdown with close

contrib/ruby/test/client_test.rb

@@ -998,6 +998,18 @@ def test_close_terminate_parent_connection
     end
   end
 
+  def test_discard_closes_connection
+    client = new_tcp_client
+
+    assert_equal [1], client.query("SELECT 1").to_a.first
+
+    client.discard!
+
+    assert_raises Trilogy::ConnectionClosed do
+      client.query("SELECT 1")
+    end
+  end
+
   def test_discard_doesnt_terminate_parent_connection
     skip("Fork isn't supported on this platform") unless Process.respond_to?(:fork)
 

inc/trilogy/socket.h

@@ -110,6 +110,5 @@ static inline int trilogy_sock_fd(trilogy_sock_t *sock) { return sock->fd_cb(soc
 trilogy_sock_t *trilogy_sock_new(const trilogy_sockopt_t *opts);
 int trilogy_sock_resolve(trilogy_sock_t *raw);
 int trilogy_sock_upgrade_ssl(trilogy_sock_t *raw);
-int trilogy_sock_discard(trilogy_sock_t *sock);
 
 #endif

src/client.c

@@ -770,7 +770,7 @@ void trilogy_free(trilogy_conn_t *conn)
 
 int trilogy_discard(trilogy_conn_t *conn)
 {
-    int rc = trilogy_sock_discard(conn->socket);
+    int rc = trilogy_sock_shutdown(conn->socket);
     if (rc == TRILOGY_OK) {
         trilogy_free(conn);
     }

src/socket.c

@@ -110,7 +110,53 @@ static int _cb_raw_close(trilogy_sock_t *_sock)
     return rc;
 }
 
-static int _cb_raw_shutdown(trilogy_sock_t *_sock) { return shutdown(trilogy_sock_fd(_sock), SHUT_RDWR); }
+static int _cb_shutdown_connect(trilogy_sock_t *_sock) {
+    (void)_sock;
+    return TRILOGY_CLOSED_CONNECTION;
+}
+static ssize_t _cb_shutdown_write(trilogy_sock_t *_sock, const void *buf, size_t nwrite) {
+    (void)_sock;
+    (void)buf;
+    (void)nwrite;
+    return TRILOGY_CLOSED_CONNECTION;
+}
+static ssize_t _cb_shutdown_read(trilogy_sock_t *_sock, void *buf, size_t nread) {
+    (void)_sock;
+    (void)buf;
+    (void)nread;
+    return TRILOGY_CLOSED_CONNECTION;
+}
+static int _cb_shutdown_wait(trilogy_sock_t *_sock, trilogy_wait_t wait) {
+    (void)_sock;
+    (void)wait;
+    return TRILOGY_OK;
+}
+static int _cb_shutdown_shutdown(trilogy_sock_t *_sock) {
+    (void)_sock;
+    return TRILOGY_OK;
+}
+
+// Shutdown will close the underlying socket fd and replace all I/O operations with stubs which perform no action.
+static int _cb_raw_shutdown(trilogy_sock_t *_sock) {
+    struct trilogy_sock *sock = (struct trilogy_sock *)_sock;
+
+    // Replace all operations with stubs which return immediately
+    sock->base.connect_cb = _cb_shutdown_connect;
+    sock->base.read_cb = _cb_shutdown_read;
+    sock->base.write_cb = _cb_shutdown_write;
+    sock->base.wait_cb = _cb_shutdown_wait;
+    sock->base.shutdown_cb = _cb_shutdown_shutdown;
+
+    // These "raw" callbacks won't attempt further operations on the socket and work correctly with fd set to -1
+    sock->base.close_cb = _cb_raw_close;
+    sock->base.fd_cb = _cb_raw_fd;
+
+    if (sock->fd != -1)
+        close(sock->fd);
+    sock->fd = -1;
+
+    return TRILOGY_OK;
+}
 
 static int set_nonblocking_fd(int sock)
 {
@@ -341,15 +387,9 @@ static int _cb_ssl_shutdown(trilogy_sock_t *_sock)
     // we need to close it. The OpenSSL explicitly states
     // not to call SSL_shutdown on a broken SSL socket.
     SSL_free(sock->ssl);
-    // Reset the handlers since we tore down SSL, so we
-    // fall back to the regular methods for detecting
-    // we have a closed connection and for the cleanup.
-    sock->base.read_cb = _cb_raw_read;
-    sock->base.write_cb = _cb_raw_write;
-    sock->base.shutdown_cb = _cb_raw_shutdown;
-    sock->base.close_cb = _cb_raw_close;
     sock->ssl = NULL;
 
+    // This will rewrite the handlers
     return _cb_raw_shutdown(_sock);
 }
 
@@ -624,28 +664,3 @@ int trilogy_sock_upgrade_ssl(trilogy_sock_t *_sock)
     sock->ssl = NULL;
     return TRILOGY_OPENSSL_ERR;
 }
-
-int trilogy_sock_discard(trilogy_sock_t *_sock)
-{
-    struct trilogy_sock *sock = (struct trilogy_sock *)_sock;
-
-    if (sock->fd < 0) {
-        return TRILOGY_OK;
-    }
-
-    int null_fd = open("/dev/null", O_RDWR | O_CLOEXEC);
-    if (null_fd < 0) {
-        return TRILOGY_SYSERR;
-    }
-
-    if (dup2(null_fd, sock->fd) < 0) {
-        close(null_fd);
-        return TRILOGY_SYSERR;
-    }
-
-    if (close(null_fd) < 0) {
-        return TRILOGY_SYSERR;
-    }
-
-    return TRILOGY_OK;
-}