Channel constructor requires an explicit size. Also implements 0-sized channels by amitmurthy · Pull Request #18832 · JuliaLang/julia

amitmurthy · 2016-10-07T14:05:35Z

As discussed in #17698 (comment), the default channel size of 32 has been removed. The size needs to be specified explicitly. Channel(Inf) is an unlimited channel, a shorter way of writing Channel(typemax(UInt))

Channel tests have been moved into its own file.

Added support for 0-sized channels (as mentioned in #17699). This provides the same behavior as produce/ consume which can be deprecated in a separate PR.

tkelman · 2016-10-08T11:08:09Z

base/channels.jl

+    put!(c,v,Val{c.sz_max==0})
+end
+
+function put!(c::Channel, v, ::Type{Val{false}})


add some comments about what this new Val argument is differentiating?

tkelman · 2016-10-08T11:11:30Z

base/docs/helpdb/Base.jl

 a full channel block till an object is removed with `take!`.

+`Channel(0)` constructs a Channel without a backing store. Consequently a `put!` on a
+0-sized channel will block till another task calls a `take!` on it. And vice-versa.


"block until"

tkelman · 2016-10-08T11:12:36Z

base/docs/helpdb/Base.jl

+`Channel(0)` constructs a Channel without a backing store. Consequently a `put!` on a
+0-sized channel will block till another task calls a `take!` on it. And vice-versa.
+
+`isready` on a 0-sized channel returns true if there are any tasks blocked on a `put!`


should be separated with either a period or another line between this and the following statement

amitmurthy · 2016-10-09T12:58:07Z

@tkelman thanks for the feedback. Have pushed a commit that makes the arguments self-explanatory and also updated the docs.

tkelman · 2016-10-09T15:49:39Z

several more cases of "block till" would be better as "block until" I think

amitmurthy · 2016-10-11T12:06:51Z

@StefanKarpinski your thoughts?

fetch on an unbuffered channel is not supported. put!, take and wait work as expected.

StefanKarpinski · 2016-10-11T19:45:44Z

Yes, in general this is good. A couple of high-level things.

It feels like Int might be a better type for the buffer size. We don't really need the high bit for this – real buffer sizes are going to be much smaller than this and we generally use Int for all sizes of things and indices into them. The constructor can still check that the size isn't negative.

Is all the Val stuff for buffered versus unbuffered really necessary? It seems like it's for performance but since it's not captured in the type of the channel objects, dispatch seems like it will end up being dynamic anyway, in which case some if/elses are going to be faster anyway. And this is for operations that seem like they'll swamp the cost of some if/elses anyway.

amitmurthy · 2016-10-12T01:55:35Z

In this case, the dispatch on values was mainly for style and readability. Will capture it in the type or replace with if/else.

amitmurthy · 2016-10-16T07:40:19Z

Updated.

amitmurthy · 2016-10-18T07:55:21Z

Deprecated Channel() instead of throwing an error.

Will squash and merge in a couple of days if there are no more comments.

tkelman · 2016-10-18T08:22:47Z

base/channels.jl

+
+    # deprecated empty constructor
+    function Channel()
+        depwarn(string("The empty constructor Channel() is deprecated. ",


why isn't this in deprecated.jl ?

The Channel{T}() constructor needs to be inside the type definition, while Channel() which is equivalent of Channel{Any}() can be outside. Thus added both in channels.jl itself.

why can't it be an outer constructor? especially with two different signatures in different places that should be removed, those comments are going to be easy to miss

How?

Channel() = Channel{Any}(32) is fine.
Channel{T}() = Channel{T}(32) is not callable.

julia> type Foo{T} foo::T end julia> Foo{T}() = Foo{T}(1) WARNING: static parameter T does not occur in signature for Type at REPL[2]:1. The method will not be callable. Foo{T}

Move channel tests into its own file. Implement 0-sized channels.

amitmurthy · 2016-10-20T13:12:01Z

@tkelman AV error is unrelated and OSX build is not starting up at all. Should I restart the build?

…).

)

) (cherry picked from commit a72aad4)

amitmurthy mentioned this pull request Oct 7, 2016

RFC: change default max channel size to typemax(Int) #17698

Closed

kshyatt added parallelism Parallel or distributed computation io Involving the I/O subsystem: libuv, read, write, etc. labels Oct 7, 2016

amitmurthy force-pushed the amitm/channel0 branch from 7a24ca1 to 6d7b960 Compare October 8, 2016 03:32

tkelman reviewed Oct 8, 2016

View reviewed changes

amitmurthy force-pushed the amitm/channel0 branch from d2f385f to 6d5d12e Compare October 9, 2016 12:56

amitmurthy force-pushed the amitm/channel0 branch from 8b450d9 to 903c464 Compare October 18, 2016 07:53

tkelman reviewed Oct 18, 2016

View reviewed changes

Channel constructor requires an explict size.

e23f4e2

Move channel tests into its own file. Implement 0-sized channels.

amitmurthy force-pushed the amitm/channel0 branch from 903c464 to e23f4e2 Compare October 20, 2016 05:16

amitmurthy merged commit f3b40bf into master Oct 21, 2016

yuyichao deleted the amitm/channel0 branch October 21, 2016 03:46

Sacha0 added a commit to Sacha0/julia that referenced this pull request May 18, 2017

Add NEWS.md entry for zero-arg Channel constructor dep (JuliaLang#18832…

cba0c69

…).

Sacha0 added deprecation This change introduces or involves a deprecation needs news A NEWS entry is required for this change labels May 18, 2017

ararslan pushed a commit that referenced this pull request May 19, 2017

Add NEWS.md entry for zero-arg Channel constructor dep (#18832). (#21932

a72aad4

)

Sacha0 removed the needs news A NEWS entry is required for this change label May 19, 2017

tkelman pushed a commit that referenced this pull request Jun 3, 2017

Add NEWS.md entry for zero-arg Channel constructor dep (#18832). (#21932

effa3bb

) (cherry picked from commit a72aad4)

fredrikekre mentioned this pull request Oct 10, 2017

Missing Channel constructor? #14570

Closed

Uh oh!

Conversation

amitmurthy commented Oct 7, 2016

Uh oh!

tkelman Oct 8, 2016

Choose a reason for hiding this comment

Uh oh!

tkelman Oct 8, 2016

Choose a reason for hiding this comment

Uh oh!

tkelman Oct 8, 2016

Choose a reason for hiding this comment

Uh oh!

amitmurthy commented Oct 9, 2016

Uh oh!

tkelman commented Oct 9, 2016

Uh oh!

amitmurthy commented Oct 11, 2016

Uh oh!

StefanKarpinski commented Oct 11, 2016

Uh oh!

amitmurthy commented Oct 12, 2016

Uh oh!

amitmurthy commented Oct 16, 2016

Uh oh!

amitmurthy commented Oct 18, 2016

Uh oh!

tkelman Oct 18, 2016 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

amitmurthy Oct 18, 2016

Choose a reason for hiding this comment

Uh oh!

tkelman Oct 18, 2016

Choose a reason for hiding this comment

Uh oh!

amitmurthy Oct 18, 2016

Choose a reason for hiding this comment

Uh oh!

amitmurthy commented Oct 20, 2016

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

5 participants

tkelman Oct 18, 2016 •

edited

Loading