Kernel: Make DoubleBuffer::try() return KResultOr

This tidies up error propagation in a number of places.

4 files changed, 12 insertions, 21 deletions

diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index 0a2ad95a26..88cdf95cc3 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -35,23 +35,21 @@ MutexProtected<IPv4Socket::List>& IPv4Socket::all_sockets()
     return *s_all_sockets;
 }
 
-OwnPtr<DoubleBuffer> IPv4Socket::create_receive_buffer()
+KResultOr<NonnullOwnPtr<DoubleBuffer>> IPv4Socket::try_create_receive_buffer()
 {
     return DoubleBuffer::try_create(256 * KiB);
 }
 
 KResultOr<NonnullRefPtr<Socket>> IPv4Socket::create(int type, int protocol)
 {
-    auto receive_buffer = IPv4Socket::create_receive_buffer();
-    if (!receive_buffer)
-        return ENOMEM;
+    auto receive_buffer = TRY(IPv4Socket::try_create_receive_buffer());
 
     if (type == SOCK_STREAM)
-        return TRY(TCPSocket::try_create(protocol, receive_buffer.release_nonnull()));
+        return TRY(TCPSocket::try_create(protocol, move(receive_buffer)));
     if (type == SOCK_DGRAM)
-        return TRY(UDPSocket::try_create(protocol, receive_buffer.release_nonnull()));
+        return TRY(UDPSocket::try_create(protocol, move(receive_buffer)));
     if (type == SOCK_RAW) {
-        auto raw_socket = adopt_ref_if_nonnull(new (nothrow) IPv4Socket(type, protocol, receive_buffer.release_nonnull(), {}));
+        auto raw_socket = adopt_ref_if_nonnull(new (nothrow) IPv4Socket(type, protocol, move(receive_buffer), {}));
         if (raw_socket)
             return raw_socket.release_nonnull();
         return ENOMEM;
diff --git a/Kernel/Net/IPv4Socket.h b/Kernel/Net/IPv4Socket.h
index 4d6cbcc35b..3ec3521acc 100644
--- a/Kernel/Net/IPv4Socket.h
+++ b/Kernel/Net/IPv4Socket.h
@@ -90,7 +90,7 @@ protected:
     void set_local_address(IPv4Address address) { m_local_address = address; }
     void set_peer_address(IPv4Address address) { m_peer_address = address; }
 
-    static OwnPtr<DoubleBuffer> create_receive_buffer();
+    static KResultOr<NonnullOwnPtr<DoubleBuffer>> try_create_receive_buffer();
 
 private:
     virtual bool is_ipv4() const override { return true; }
diff --git a/Kernel/Net/LocalSocket.cpp b/Kernel/Net/LocalSocket.cpp
index 43c59e0a46..9deaa786d2 100644
--- a/Kernel/Net/LocalSocket.cpp
+++ b/Kernel/Net/LocalSocket.cpp
@@ -36,16 +36,9 @@ void LocalSocket::for_each(Function<void(const LocalSocket&)> callback)
 
 KResultOr<NonnullRefPtr<LocalSocket>> LocalSocket::try_create(int type)
 {
-    auto client_buffer = DoubleBuffer::try_create();
-    if (!client_buffer)
-        return ENOMEM;
-    auto server_buffer = DoubleBuffer::try_create();
-    if (!server_buffer)
-        return ENOMEM;
-    auto socket = adopt_ref_if_nonnull(new (nothrow) LocalSocket(type, client_buffer.release_nonnull(), server_buffer.release_nonnull()));
-    if (socket)
-        return socket.release_nonnull();
-    return ENOMEM;
+    auto client_buffer = TRY(DoubleBuffer::try_create());
+    auto server_buffer = TRY(DoubleBuffer::try_create());
+    return adopt_nonnull_ref_or_enomem(new (nothrow) LocalSocket(type, move(client_buffer), move(server_buffer)));
 }
 
 KResultOr<SocketPair> LocalSocket::try_create_connected_pair(int type)
diff --git a/Kernel/Net/TCPSocket.cpp b/Kernel/Net/TCPSocket.cpp
index a3b8dd7ac0..22905a61c8 100644
--- a/Kernel/Net/TCPSocket.cpp
+++ b/Kernel/Net/TCPSocket.cpp
@@ -97,10 +97,10 @@ RefPtr<TCPSocket> TCPSocket::create_client(const IPv4Address& new_local_address,
         if (table.contains(tuple))
             return {};
 
-        auto receive_buffer = create_receive_buffer();
-        if (!receive_buffer)
+        auto receive_buffer = try_create_receive_buffer();
+        if (receive_buffer.is_error())
             return {};
-        auto client_or_error = TCPSocket::try_create(protocol(), receive_buffer.release_nonnull());
+        auto client_or_error = TCPSocket::try_create(protocol(), receive_buffer.release_value());
         if (client_or_error.is_error())
             return {};