Add the rest of the damn presentation

This commit is contained in:
Vincent Ambo 2016-09-22 15:37:17 +02:00
parent 6c456a06c7
commit fac2474ac6
5 changed files with 164 additions and 6 deletions

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@ -114,16 +114,102 @@ hello(Name) ->
% ok % ok
``` ```
---
## [fit] Hello ~~world~~ Joe is boring!
## [fit] Lets do it with processes.
---
### Hello Server
```erlang
-module(hello_server).
-export([start_server/0]).
start_server() ->
spawn(fun() -> server() end).
server() ->
receive
{greet, Name} ->
io:format("Hello ~s!~n", [Name]),
server()
end.
```
--- ---
## Drag & Drop images ## [fit] Some issues with that ...
### Simply *drop an image onto the Deckset window* and the Markdown you need to display the image is automatically created and *copied to the clipboard.* - What about unused messages?
- What if the server crashes?
--- ---
* This works with both local files and web images ## [fit] Part 2: Open Telecom Platform
* You dont _need_ to drag the file, you can also type the Markdown yourself if you know how
![left,filtered](http://deckset-assets.s3-website-us-east-1.amazonaws.com/colnago1.jpg) ### **It's called Erlang/OTP for a reason.**
---
# OTP: An Application Framework
- Supervision - keep processes alive!
- OTP Behaviours - common process patterns
- Extensive standard library
- Error handling, debuggers, testing, ...
- Lots more!
^ Standard library includes lots of things from simple network libraries over testing frameworks to cryptography, complete LDAP clients etc.
---
# Supervision
![inline](http://erlang.org/doc/design_principles/sup6.gif)
^ Supervision keeps processes alive, different restart behaviours, everything should be supervised to avoid "process" (and therefore memory) leaks
---
# OTP Behaviours
* `gen_server`
* `gen_statem`
* `gen_event`
* `supervisor`
^ gen = generic. explain server, explain statem, event = event handling with registered handlers, supervisor ...
---
`gen_server`
---
## [fit] Part 3: BEAM
### Bogdan/Bjørn Erlang Abstract machine
---
## A VM for Erlang
* Many were written, BEAM survived
* Concurrent garbage-collection
* Lower-level bytecode than JVM
* Very open to new languages
(Elixir, LFE, Joxa, ...)
---
## What next?
* Ole's talk, obviously!
* Learn You Some Erlang!
www.learnyousomeerlang.com
* Watch out for the Oslo BEAM meetup group

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@ -2,7 +2,7 @@
-export([hello/1]). -export([hello/1]).
hello(Name) -> hello(Name) ->
io:format("Hello ~s!~n", [Name]). io:format("Hey ~s!~n", [Name]).
% 3> c(hello2). % 3> c(hello2).
% {ok,hello2} % {ok,hello2}

12
src/hello_server.erl Normal file
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@ -0,0 +1,12 @@
-module(hello_server).
-export([start_server/0, server/0]).
start_server() ->
spawn(fun() -> server() end).
server() ->
receive
{greet, Name} ->
io:format("Hello ~s!~n", [Name]),
hello_server:server()
end.

36
src/hello_server2.erl Normal file
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@ -0,0 +1,36 @@
-module(hello_server2).
-behaviour(gen_server).
-compile(export_all).
%%% Start callback for supervisor
start_link() ->
gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
%%% gen_server callbacks
init([]) ->
{ok, sets:new()}.
handle_call({greet, Name}, _From, State) ->
io:format("Hello ~s!~n", [Name]),
NewState = sets:add_element(Name, State),
{reply, ok, NewState};
handle_call({bye, Name}, _From, State) ->
io:format("Goodbye ~s!~n", [Name]),
NewState = sets:del_element(Name, State),
{reply, ok, NewState}.
terminate(normal, State) ->
[io:format("Goodbye ~s!~n", [Name]) || Name <- State],
ok.
%%% Unused gen_server callbacks
code_change(_OldVsn, State, _Extra) ->
{ok, State}.
handle_info(_Info, State) ->
{noreply, State}.
handle_cast(_Request, State) ->
{noreply, State}.

24
src/hello_sup.erl Normal file
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@ -0,0 +1,24 @@
-module(hello_sup).
-behaviour(supervisor).
-export([start_link/0, init/1]).
%%% Module API
start_link() ->
supervisor:start_link({local, ?MODULE}, ?MODULE, []).
%%% Supervisor callbacks
init([]) ->
Children = [hello_spec()],
{ok, { {one_for_one, 5, 10}, Children}}.
%%% Private
hello_spec() ->
#{id => hello_server2,
start => {hello_server2, start_link, []},
restart => permanent,
shutdown => 5000,
type => worker,
module => [hello_server2]}.