Chan package:base

Unbounded channels. The channels are implemented with MVars and therefore inherit all the caveats that apply to MVars (possibility of races, deadlocks etc). The stm (software transactional memory) library has a more robust implementation of channels called TChans.

Chan is an abstract type representing an unbounded FIFO channel.

Duplicate a Chan: the duplicate channel begins empty, but data written to either channel from then on will be available from both. Hence this creates a kind of broadcast channel, where data written by anyone is seen by everyone else. (Note that a duplicated channel is not equal to its original. So: fmap (c /=) $ dupChan c returns True for all c.)

Return a lazy list representing the contents of the supplied Chan, much like hGetContents.

Build and return a new instance of Chan.

Read the next value from the Chan. Blocks when the channel is empty. Since the read end of a channel is an MVar, this operation inherits fairness guarantees of MVars (e.g. threads blocked in this operation are woken up in FIFO order). Throws BlockedIndefinitelyOnMVar when the channel is empty and no other thread holds a reference to the channel.

Write a value to a Chan.

Write an entire list of items to a Chan.

How to collect a backtrace when an exception is thrown.

Will the given BacktraceMechanism be used when collecting backtraces?

Set whether the given BacktraceMechanism will be used when collecting backtraces?

The atomic exchange operation. Atomically exchanges the value at the first address with the Addr# given as second argument. Implies a read barrier. Warning: this can fail with an unchecked exception.

The atomic exchange operation. Atomically exchanges the value at the address with the given value. Returns the old value. Implies a read barrier. Warning: this can fail with an unchecked exception.

Given an array, and offset in machine words, and a value to AND, atomically AND the value into the element. Returns the value of the element before the operation. Implies a full memory barrier. Warning: this can fail with an unchecked exception.

Given an address, and a value to AND, atomically AND the value into the element. Returns the value of the element before the operation. Implies a full memory barrier. Warning: this can fail with an unchecked exception.

Catch any Exception type in the IO monad. Note that this function is strict in the action. That is, catchAny undefined b == _|_. See for details. If you rethrow an exception, you should reuse the supplied ExceptionContext.