diff options
Diffstat (limited to 'Channels/README.md')
| -rw-r--r-- | Channels/README.md | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/Channels/README.md b/Channels/README.md index 7d19f2b..639b8ff 100644 --- a/Channels/README.md +++ b/Channels/README.md @@ -8,12 +8,59 @@ Further reading on CSP: http://www.usingcsp.com/cspbook.pdf ## Source +### chans.b:33,36 +This statement shows three channels being made. -## Demo +`done` is an unbuffered channel which transports integer values. + +`msgChan` is an unbuffered channel, instantiated using buffered channel syntax, which transports strings. + +`numChan` is a buffered channel which transports a tuple representing an integer pair. + +### chans.b:38 + +The `spawn` statement is used to create a new process running a given function, in this case `summer()`. + +### chans.b:40,45 + +This section loads number pairs from the variable `i` and the number 2 from 0 to 14, covering 15 total iterations. After the iterative statement completes, a (later discarded) value is passed to the channel `done`. The first (and only) value in `msgChan` is then read out and printed. + +Note: Writing to a channel whose buffer (or lack thereof) is currently full is a blocking operation. Similarly, reading from a channel whose buffer (or lack thereof) is currently empty is a blocking operation. +### chans.b:13,28 + +The function `summer()` operates an infinite loop which operates a single `alt` statement which is similar to a switch-case statement which operates on the presence of values within a channel. + +The three channels are used to coordinate operation between the two processes. + +`num` is checked first and a tuple of values is pulled out: a value and a power to raise said value to. The `n^p` operation is shown as `n**p` in Limbo, with the result being added to sum's current value. + +`done` is checked after `num` has no more values in its buffer. If a value is found, the sum is stringified and passed down `msg` and the looping condition is unset. + +The default value, indicated by `*=>`, is used when no channels have a value, so we sleep the current process for 5ms to de-schedule ourselves in case some form of scheduling is holding up our communications. + +## Demo + ; limbo chans.b + ; chans + Sum: 0 + Sum: 1 + Sum: 5 + Sum: 14 + Sum: 30 + Sum: 55 + Sum: 91 + Sum: 140 + Sum: 204 + Sum: 285 + Sum: 385 + Sum: 506 + Sum: 650 + Final sum: 650 + ; ## Exercises -- +- Can you pass an ADT over a channel? +- What happens if you pass a `ref` type over a channel? |