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ReadableStreamDefaultReader: releaseLock() method

The releaseLock() method of the ReadableStreamDefaultReader interface releases the reader's lock on the stream.

If the associated stream is errored when the lock is released, the reader will appear errored in that same way subsequently; otherwise, the reader will appear closed.

If the reader's lock is released while it still has pending read requests then the promises returned by the reader's ReadableStreamDefaultReader.read() method are immediately rejected with a TypeError. Unread chunks remain in the stream's internal queue and can be read later by acquiring a new reader.

Syntax

releaseLock()

Parameters

None.

Return value

None (undefined).

Exceptions

TypeError: Thrown if the source object is not a ReadableStreamDefaultReader.

Examples

function fetchStream() {
  const reader = stream.getReader();

  // ...

  reader.releaseLock();

  // ...
}

Specifications

Specification
Streams Standard # ref-for-default-reader-release-lock②

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
`releaseLock`	78	79	65	No	65	≤13.1	78	78	65	56	≤13.4	12.0
`reject_pending_read_request`	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	102	No	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	No	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	102	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).	No	No `releaseLock()` throws if there are pending read requests (rather than pending read requests being rejected).