From f5cb4c20422a35b51bfba3391744f8bcb54f7581 Mon Sep 17 00:00:00 2001 From: Eliza Weisman Date: Mon, 16 Nov 2020 12:29:03 -0800 Subject: net: Add send/recv buf size methods to `TcpSocket` (#3145) This commit adds `set_{send, recv}_buffer_size` methods to `TcpSocket` for setting the size of the TCP send and receive buffers, and `{send, recv}_buffer_size` methods for returning the current value. These just call into similar methods on `mio`'s `TcpSocket` type, which were added in tokio-rs/mio#1384. Refs: #3082 Signed-off-by: Eliza Weisman --- tokio/Cargo.toml | 2 +- tokio/src/net/tcp/socket.rs | 68 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+), 1 deletion(-) diff --git a/tokio/Cargo.toml b/tokio/Cargo.toml index 1c454b9a..1af88fe0 100644 --- a/tokio/Cargo.toml +++ b/tokio/Cargo.toml @@ -98,7 +98,7 @@ bytes = { version = "0.6.0", optional = true } futures-core = { version = "0.3.0", optional = true } lazy_static = { version = "1.4.0", optional = true } memchr = { version = "2.2", optional = true } -mio = { version = "0.7.5", optional = true } +mio = { version = "0.7.6", optional = true } num_cpus = { version = "1.8.0", optional = true } parking_lot = { version = "0.11.0", optional = true } slab = { version = "0.4.1", optional = true } diff --git a/tokio/src/net/tcp/socket.rs b/tokio/src/net/tcp/socket.rs index 7aa1b063..b10898bf 100644 --- a/tokio/src/net/tcp/socket.rs +++ b/tokio/src/net/tcp/socket.rs @@ -280,6 +280,74 @@ impl TcpSocket { self.inner.get_reuseport() } + /// Sets the size of the TCP send buffer on this socket. + /// + /// On most operating systems, this sets the `SO_SNDBUF` socket option. + pub fn set_send_buffer_size(&self, size: u32) -> io::Result<()> { + self.inner.set_send_buffer_size(size) + } + + /// Returns the size of the TCP send buffer for this socket. + /// + /// On most operating systems, this is the value of the `SO_SNDBUF` socket + /// option. + /// + /// Note that if [`set_send_buffer_size`] has been called on this socket + /// previously, the value returned by this function may not be the same as + /// the argument provided to `set_send_buffer_size`. This is for the + /// following reasons: + /// + /// * Most operating systems have minimum and maximum allowed sizes for the + /// send buffer, and will clamp the provided value if it is below the + /// minimum or above the maximum. The minimum and maximum buffer sizes are + /// OS-dependent. + /// * Linux will double the buffer size to account for internal bookkeeping + /// data, and returns the doubled value from `getsockopt(2)`. As per `man + /// 7 socket`: + /// > Sets or gets the maximum socket send buffer in bytes. The + /// > kernel doubles this value (to allow space for bookkeeping + /// > overhead) when it is set using `setsockopt(2)`, and this doubled + /// > value is returned by `getsockopt(2)`. + /// + /// [`set_send_buffer_size`]: #method.set_send_buffer_size + pub fn send_buffer_size(&self) -> io::Result { + self.inner.get_send_buffer_size() + } + + /// Sets the size of the TCP receive buffer on this socket. + /// + /// On most operating systems, this sets the `SO_RCVBUF` socket option. + pub fn set_recv_buffer_size(&self, size: u32) -> io::Result<()> { + self.inner.set_recv_buffer_size(size) + } + + /// Returns the size of the TCP receive buffer for this socket. + /// + /// On most operating systems, this is the value of the `SO_RCVBUF` socket + /// option. + /// + /// Note that if [`set_recv_buffer_size`] has been called on this socket + /// previously, the value returned by this function may not be the same as + /// the argument provided to `set_send_buffer_size`. This is for the + /// following reasons: + /// + /// * Most operating systems have minimum and maximum allowed sizes for the + /// receive buffer, and will clamp the provided value if it is below the + /// minimum or above the maximum. The minimum and maximum buffer sizes are + /// OS-dependent. + /// * Linux will double the buffer size to account for internal bookkeeping + /// data, and returns the doubled value from `getsockopt(2)`. As per `man + /// 7 socket`: + /// > Sets or gets the maximum socket send buffer in bytes. The + /// > kernel doubles this value (to allow space for bookkeeping + /// > overhead) when it is set using `setsockopt(2)`, and this doubled + /// > value is returned by `getsockopt(2)`. + /// + /// [`set_recv_buffer_size`]: #method.set_recv_buffer_size + pub fn recv_buffer_size(&self) -> io::Result { + self.inner.get_recv_buffer_size() + } + /// Get the local address of this socket. /// /// Will fail on windows if called before `bind`. -- cgit v1.2.3