From faf881913e2c20fa27e5ba44541bd4e210f8e3f2 Mon Sep 17 00:00:00 2001
From: "Ivan I. Ovchinnikov" <mail@iovchinnikov.ru>
Date: Mon, 13 Mar 2023 11:58:28 +0300
Subject: [PATCH] lab 2 done

---
 src/proc_sieve.erl | 66 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 src/proc_sieve.erl

diff --git a/src/proc_sieve.erl b/src/proc_sieve.erl
new file mode 100644
index 0000000..44330ec
--- /dev/null
+++ b/src/proc_sieve.erl
@@ -0,0 +1,66 @@
+-module(proc_sieve).
+
+-export([generate/1]).
+-export([proc_sieve_func/2]).
+-export([gen_print/1]).
+
+proc_sieve_func(0, InvalidPid) ->
+    receive 
+        N -> proc_sieve_func(N, InvalidPid)
+    after 1000 ->
+        io:format("time out in N=0~n")
+    end; 
+
+proc_sieve_func(N, Pid) when is_pid(Pid)-> % 6. all others to get prime
+receive
+    {done, Return} ->         % 6.2. when done
+        Pid ! {done, self()}, % 6.2. send done down and wait
+        receive               % 6.3. as received a list 
+            ResultsList ->    % 6.3. concatenate it with our number and send up
+                Return ! [N] ++ ResultsList
+        end;
+    Num when Num rem N == 0 ->    % 6.1. as we get non-prine number 
+        proc_sieve_func(N, Pid);  % 6.1. just go check other numbers
+    Num when Num rem N /= 0 ->    % 6.1. otherwise
+        Pid ! Num,                % 6.1. send our prime number to an upper
+        proc_sieve_func(N, Pid)   % 6.1. anyway go check other numbers
+
+end;
+proc_sieve_func(N, Anything) -> % 2.3. first one to get a prime (anything in pid)
+receive
+    {done, ReqPid} ->             % 5. as we get done-flag
+        ReqPid ! [N];             % 5.1 just send our number as a list
+    Num when Num rem N == 0 ->    % 3. as we get non-prine number 
+        proc_sieve_func(N, Anything);  % 3. just go check other numbers
+    Num when Num rem N /= 0 ->    % 3.1. otherwise start a new process
+        Pid = spawn(proc_sieve, proc_sieve_func, [0, anything]),
+        Pid ! Num,                % 3.1. and send that prime number to it
+        proc_sieve_func(N, Pid)   % 3.2. anyway go check other numbers
+after 5000 ->
+        io:format("time out N = ~p~n", [N]),
+        {fail, timeout}
+end.
+
+sieve() -> % 1.2. spawn a new process with function, 0 and no pid
+    spawn(proc_sieve, proc_sieve_func, [0, anything]).
+
+generate(MaxN) when MaxN > 1 -> % 1. exception if MaxN < 2
+    Pid = sieve(),              % 1.1. start a new process with no parameters
+    nextNumber(2, MaxN, Pid).   % 1.3. let's send numbers, starting from 2
+
+nextNumber(Stopword, Stopword, To) -> % 4. when we get to the stopword
+    To ! {done, self()},              % 4.1. send a done-flag and initial pid
+    receive                           % 4.2. wait for message with result 
+        Result -> Result              % 4.3. and do nothing (should be printed)
+    end;
+
+nextNumber(N, Stopword, To) ->       % 2. 
+    To ! N,                          % 2.1. Send the passed number to process
+    nextNumber(N + 1, Stopword, To). % 2.2. Send the next number to process
+
+gen_print(MaxN) ->
+    List = generate(MaxN),
+    lists:foreach(fun(T) -> 
+                         io:format("~w, ", [T]) 
+                  end,
+                  List).