pub struct Builder { /* private fields */ }
Expand description
Builds Tokio Runtime with custom configuration values.
Methods can be chained in order to set the configuration values. The
Runtime is constructed by calling build
.
New instances of Builder
are obtained via Builder::new
.
See function level documentation for details on the various configuration settings.
Examples
extern crate tokio;
extern crate tokio_timer;
use std::time::Duration;
use tokio::runtime::Builder;
use tokio_timer::clock::Clock;
fn main() {
// build Runtime
let mut runtime = Builder::new()
.blocking_threads(4)
.clock(Clock::system())
.core_threads(4)
.keep_alive(Some(Duration::from_secs(60)))
.name_prefix("my-custom-name-")
.stack_size(3 * 1024 * 1024)
.build()
.unwrap();
// use runtime ...
}
Implementations§
source§impl Builder
impl Builder
sourcepub fn new() -> Builder
pub fn new() -> Builder
Returns a new runtime builder initialized with default configuration values.
Configuration methods can be chained on the return value.
sourcepub fn clock(&mut self, clock: Clock) -> &mut Self
pub fn clock(&mut self, clock: Clock) -> &mut Self
Set the Clock
instance that will be used by the runtime.
sourcepub fn core_threads(&mut self, val: usize) -> &mut Self
pub fn core_threads(&mut self, val: usize) -> &mut Self
Set the maximum number of worker threads for the Runtime
’s thread pool.
This must be a number between 1 and 32,768 though it is advised to keep this value on the smaller side.
The default value is the number of cores available to the system.
Examples
let mut rt = runtime::Builder::new()
.core_threads(4)
.build()
.unwrap();
sourcepub fn blocking_threads(&mut self, val: usize) -> &mut Self
pub fn blocking_threads(&mut self, val: usize) -> &mut Self
Set the maximum number of concurrent blocking sections in the Runtime
’s
thread pool.
When the maximum concurrent blocking
calls is reached, any further
calls to blocking
will return NotReady
and the task is notified once
previously in-flight calls to blocking
return.
This must be a number between 1 and 32,768 though it is advised to keep this value on the smaller side.
The default value is 100.
Examples
let mut rt = runtime::Builder::new()
.blocking_threads(200)
.build();
sourcepub fn keep_alive(&mut self, val: Option<Duration>) -> &mut Self
pub fn keep_alive(&mut self, val: Option<Duration>) -> &mut Self
Set the worker thread keep alive duration for threads in the Runtime
’s
thread pool.
If set, a worker thread will wait for up to the specified duration for work, at which point the thread will shutdown. When work becomes available, a new thread will eventually be spawned to replace the one that shut down.
When the value is None
, the thread will wait for work forever.
The default value is None
.
Examples
use std::time::Duration;
let mut rt = runtime::Builder::new()
.keep_alive(Some(Duration::from_secs(30)))
.build();
sourcepub fn name_prefix<S: Into<String>>(&mut self, val: S) -> &mut Self
pub fn name_prefix<S: Into<String>>(&mut self, val: S) -> &mut Self
Set name prefix of threads spawned by the Runtime
’s thread pool.
Thread name prefix is used for generating thread names. For example, if
prefix is my-pool-
, then threads in the pool will get names like
my-pool-1
etc.
The default prefix is “tokio-runtime-worker-”.
Examples
let mut rt = runtime::Builder::new()
.name_prefix("my-pool-")
.build();
sourcepub fn stack_size(&mut self, val: usize) -> &mut Self
pub fn stack_size(&mut self, val: usize) -> &mut Self
Set the stack size (in bytes) for worker threads.
The actual stack size may be greater than this value if the platform specifies minimal stack size.
The default stack size for spawned threads is 2 MiB, though this particular stack size is subject to change in the future.
Examples
let mut rt = runtime::Builder::new()
.stack_size(32 * 1024)
.build();
sourcepub fn after_start<F>(&mut self, f: F) -> &mut Selfwhere
F: Fn() + Send + Sync + 'static,
pub fn after_start<F>(&mut self, f: F) -> &mut Selfwhere
F: Fn() + Send + Sync + 'static,
Execute function f
after each thread is started but before it starts
doing work.
This is intended for bookkeeping and monitoring use cases.
Examples
let thread_pool = runtime::Builder::new()
.after_start(|| {
println!("thread started");
})
.build();
sourcepub fn before_stop<F>(&mut self, f: F) -> &mut Selfwhere
F: Fn() + Send + Sync + 'static,
pub fn before_stop<F>(&mut self, f: F) -> &mut Selfwhere
F: Fn() + Send + Sync + 'static,
Execute function f
before each thread stops.
This is intended for bookkeeping and monitoring use cases.
Examples
let thread_pool = runtime::Builder::new()
.before_stop(|| {
println!("thread stopping");
})
.build();