package context

Import Path
	golang.org/x/net/context (on go.dev)

Dependency Relation
	imports 2 packages, and imported by one package


Involved Source Files

	
		Package context defines the Context type, which carries deadlines,
		cancelation signals, and other request-scoped values across API boundaries
		and between processes.
		As of Go 1.7 this package is available in the standard library under the
		name context.  https://golang.org/pkg/context.

		Incoming requests to a server should create a Context, and outgoing calls to
		servers should accept a Context. The chain of function calls between must
		propagate the Context, optionally replacing it with a modified copy created
		using WithDeadline, WithTimeout, WithCancel, or WithValue.

		Programs that use Contexts should follow these rules to keep interfaces
		consistent across packages and enable static analysis tools to check context
		propagation:

		Do not store Contexts inside a struct type; instead, pass a Context
		explicitly to each function that needs it. The Context should be the first
		parameter, typically named ctx:

			func DoSomething(ctx context.Context, arg Arg) error {
				// ... use ctx ...
			}

		Do not pass a nil Context, even if a function permits it. Pass context.TODO
		if you are unsure about which Context to use.

		Use context Values only for request-scoped data that transits processes and
		APIs, not for passing optional parameters to functions.

		The same Context may be passed to functions running in different goroutines;
		Contexts are safe for simultaneous use by multiple goroutines.

		See http://blog.golang.org/context for example code for a server that uses
		Contexts.

	      go17.go
	      go19.go


Package-Level Type Names (total 2, both are exported)


	/* sort exporteds by:  |  */
	
		A CancelFunc tells an operation to abandon its work.
		A CancelFunc does not wait for the work to stop.
		After the first call, subsequent calls to a CancelFunc do nothing.



	
		A Context carries a deadline, a cancelation signal, and other values across
		API boundaries.

		Context's methods may be called by multiple goroutines simultaneously.





Package-Level Functions (total 6, all are exported)


	
		Background returns a non-nil, empty Context. It is never canceled, has no
		values, and has no deadline. It is typically used by the main function,
		initialization, and tests, and as the top-level Context for incoming
		requests.


	
		TODO returns a non-nil, empty Context. Code should use context.TODO when
		it's unclear which Context to use or it is not yet available (because the
		surrounding function has not yet been extended to accept a Context
		parameter).  TODO is recognized by static analysis tools that determine
		whether Contexts are propagated correctly in a program.


	
		WithCancel returns a copy of parent with a new Done channel. The returned
		context's Done channel is closed when the returned cancel function is called
		or when the parent context's Done channel is closed, whichever happens first.

		Canceling this context releases resources associated with it, so code should
		call cancel as soon as the operations running in this Context complete.


	
		WithDeadline returns a copy of the parent context with the deadline adjusted
		to be no later than d. If the parent's deadline is already earlier than d,
		WithDeadline(parent, d) is semantically equivalent to parent. The returned
		context's Done channel is closed when the deadline expires, when the returned
		cancel function is called, or when the parent context's Done channel is
		closed, whichever happens first.

		Canceling this context releases resources associated with it, so code should
		call cancel as soon as the operations running in this Context complete.


	
		WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)).

		Canceling this context releases resources associated with it, so code should
		call cancel as soon as the operations running in this Context complete:

			func slowOperationWithTimeout(ctx context.Context) (Result, error) {
				ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
				defer cancel()  // releases resources if slowOperation completes before timeout elapses
				return slowOperation(ctx)
			}


	
		WithValue returns a copy of parent in which the value associated with key is
		val.

		Use context Values only for request-scoped data that transits processes and
		APIs, not for passing optional parameters to functions.




Package-Level Variables (total 4, in which 2 are exported)


	
		Canceled is the error returned by Context.Err when the context is canceled.


	
		DeadlineExceeded is the error returned by Context.Err when the context's
		deadline passes.