Control.Concurrent.STM.TBQueue
| Copyright | (c) The University of Glasgow 2012 |
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) |
| Maintainer | [email protected] |
| Stability | experimental |
| Portability | non-portable (requires STM) |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Contents
Description
TBQueue is a bounded version of TQueue. The queue has a maximum capacity set when it is created. If the queue already contains the maximum number of elements, then writeTBQueue blocks until an element is removed from the queue.
The implementation is based on the traditional purely-functional queue representation that uses two lists to obtain amortised O(1) enqueue and dequeue operations.
Since: stm-2.4
TBQueue
TBQueue is an abstract type representing a bounded FIFO channel.
Since: stm-2.4
Instances
Builds and returns a new instance of TBQueue.
newTBQueueIO :: Natural -> IO (TBQueue a) Source
IO version of newTBQueue. This is useful for creating top-level TBQueues using unsafePerformIO, because using atomically inside unsafePerformIO isn't possible.
readTBQueue :: TBQueue a -> STM a Source
Read the next value from the TBQueue.
tryReadTBQueue :: TBQueue a -> STM (Maybe a) Source
A version of readTBQueue which does not retry. Instead it returns Nothing if no value is available.
flushTBQueue :: TBQueue a -> STM [a] Source
Efficiently read the entire contents of a TBQueue into a list. This function never retries.
Since: stm-2.4.5
peekTBQueue :: TBQueue a -> STM a Source
Get the next value from the TBQueue without removing it, retrying if the channel is empty.
tryPeekTBQueue :: TBQueue a -> STM (Maybe a) Source
A version of peekTBQueue which does not retry. Instead it returns Nothing if no value is available.
writeTBQueue :: TBQueue a -> a -> STM () Source
Write a value to a TBQueue; blocks if the queue is full.
unGetTBQueue :: TBQueue a -> a -> STM () Source
Put a data item back onto a channel, where it will be the next item read. Blocks if the queue is full.
lengthTBQueue :: TBQueue a -> STM Natural Source
Return the length of a TBQueue.
Since: stm-2.5.0.0
isEmptyTBQueue :: TBQueue a -> STM Bool Source
Returns True if the supplied TBQueue is empty.
isFullTBQueue :: TBQueue a -> STM Bool Source
Returns True if the supplied TBQueue is full.
Since: stm-2.4.3
© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/8.10.2/docs/html/libraries/stm-2.5.0.0/Control-Concurrent-STM-TBQueue.html