[tarantool-patches] [PATCH] test: fix flaky socket test

[Ilya Kosarev <i.kosarev@tarantool.org>]

socket.test had a number of problems:
- racing condition on closing socket around line 640
- racing condition on waiting around line 42
- racing conditions on "receiving_socket:recv" around line 777
Now they are solved.

Closes #4451, #4426
---
Branch: https://github.com/tarantool/tarantool/tree/i.kosarev/gh-4426-4451-fix-socket-test
Issues: https://github.com/tarantool/tarantool/issues/4426 https://github.com/tarantool/tarantool/issues/4451

 test/app/socket.result   | 43 +++++++++++++++++++++++++++++++++-------
 test/app/socket.test.lua | 22 ++++++++++++++++----
 2 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/test/app/socket.result b/test/app/socket.result
index fd299424c..811f6b4e9 100644
--- a/test/app/socket.result
+++ b/test/app/socket.result
@@ -107,11 +107,11 @@ s:nonblock(true)
 ---
 - true
 ...
-s:readable(.1)
+s:readable(.5)
 ---
 - true
 ...
-s:wait(.1)
+s:wait(.5)
 ---
 - RW
 ...
@@ -1822,8 +1822,14 @@ test_run:cmd("setopt delimiter ';'")
 ---
 - true
 ...
+socket_opened = true
 cfiber = fiber.create(function(sc, rch, wch)
-    while sc:send(wch:get()) and rch:put(sc:receive("*l")) do end
+    while socket_opened do
+        sc:send(wch:get())
+        local data = sc:receive("*l")
+        if not socket_opened then sc:close() end
+        rch:put(data)
+    end
 end, sc, rch, wch);
 ---
 ...
@@ -1936,6 +1942,9 @@ c:receive("*l")
 ---
 - 
 ...
+socket_opened = false
+---
+...
 wch:put("Fu")
 ---
 - true
@@ -1944,10 +1953,6 @@ c:send("354 Please type your message\n")
 ---
 - 29
 ...
-sc:close()
----
-- 1
-...
 c:receive("*l", "Line: ")
 ---
 - null
@@ -2292,6 +2297,9 @@ sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
 ---
 - 0
 ...
+fiber.yield()
+---
+...
 received_message = receiving_socket:recv()
 ---
 ...
@@ -2315,6 +2323,9 @@ sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
 ---
 - 0
 ...
+fiber.yield()
+---
+...
 received_message, from = receiving_socket:recvfrom()
 ---
 ...
@@ -2392,6 +2403,9 @@ sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
 ---
 - 0
 ...
+fiber.yield()
+---
+...
 received_message = receiving_socket:recv(512)
 ---
 ...
@@ -2415,6 +2429,9 @@ sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
 ---
 - 0
 ...
+fiber.yield()
+---
+...
 received_message, from = receiving_socket:recvfrom(512)
 ---
 ...
@@ -2452,6 +2469,9 @@ sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
 ---
 - 1025
 ...
+fiber.yield()
+---
+...
 received_message = receiving_socket:recv()
 ---
 ...
@@ -2484,6 +2504,9 @@ sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
 ---
 - 1025
 ...
+fiber.yield()
+---
+...
 received_message, from = receiving_socket:recvfrom()
 ---
 ...
@@ -2523,6 +2546,9 @@ sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
 ---
 - 1025
 ...
+fiber.yield()
+---
+...
 received_message = receiving_socket:recv(512)
 ---
 ...
@@ -2566,6 +2592,9 @@ sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
 ---
 - 1025
 ...
+fiber.yield()
+---
+...
 received_message, from = receiving_socket:recvfrom(512)
 ---
 ...
diff --git a/test/app/socket.test.lua b/test/app/socket.test.lua
index c72d41763..8cb693735 100644
--- a/test/app/socket.test.lua
+++ b/test/app/socket.test.lua
@@ -39,8 +39,8 @@ s:nonblock(false)
 s:nonblock()
 s:nonblock(true)
 
-s:readable(.1)
-s:wait(.1)
+s:readable(.5)
+s:wait(.5)
 socket.iowait(s:fd(), 'RW')
 socket.iowait(s:fd(), 3)
 socket.iowait(s:fd(), 'R')
@@ -619,8 +619,14 @@ s:settimeout(100500)
 rch, wch = fiber.channel(1), fiber.channel(1)
 sc = socket.connect(host, port)
 test_run:cmd("setopt delimiter ';'")
+socket_opened = true
 cfiber = fiber.create(function(sc, rch, wch)
-    while sc:send(wch:get()) and rch:put(sc:receive("*l")) do end
+    while socket_opened do
+        sc:send(wch:get())
+        local data = sc:receive("*l")
+        if not socket_opened then sc:close() end
+        rch:put(data)
+    end
 end, sc, rch, wch);
 test_run:cmd("setopt delimiter ''");
 
@@ -651,9 +657,9 @@ rch:get()
 wch:put("DATA\n")
 c:receive(4)
 c:receive("*l")
+socket_opened = false
 wch:put("Fu")
 c:send("354 Please type your message\n")
-sc:close()
 c:receive("*l", "Line: ")
 c:receive()
 c:receive(10)
@@ -778,6 +784,7 @@ e == errno.EAGAIN -- expected true
 
 -- case: recv, zero datagram
 sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
+fiber.yield()
 received_message = receiving_socket:recv()
 e = receiving_socket:errno()
 received_message == '' -- expected true
@@ -786,6 +793,7 @@ e == 0 -- expected true
 
 -- case: recvfrom, zero datagram
 sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
+fiber.yield()
 received_message, from = receiving_socket:recvfrom()
 e = receiving_socket:errno()
 received_message == '' -- expected true
@@ -812,6 +820,7 @@ e == errno.EAGAIN -- expected true
 
 -- case: recv, zero datagram, explicit size
 sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
+fiber.yield()
 received_message = receiving_socket:recv(512)
 e = receiving_socket:errno()
 received_message == '' -- expected true
@@ -820,6 +829,7 @@ e == 0 -- expected true
 
 -- case: recvfrom, zero datagram, explicit size
 sendto_zero(sending_socket, '127.0.0.1', receiving_socket_port)
+fiber.yield()
 received_message, from = receiving_socket:recvfrom(512)
 e = receiving_socket:errno()
 received_message == '' -- expected true
@@ -833,6 +843,7 @@ message = string.rep('x', message_len)
 
 -- case: recv, non-zero length datagram, the buffer size should be evaluated
 sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
+fiber.yield()
 received_message = receiving_socket:recv()
 e = receiving_socket:errno()
 received_message == message -- expected true
@@ -844,6 +855,7 @@ e
 -- case: recvfrom, non-zero length datagram, the buffer size should be
 -- evaluated
 sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
+fiber.yield()
 received_message, from = receiving_socket:recvfrom()
 e = receiving_socket:errno()
 received_message == message -- expected true
@@ -856,6 +868,7 @@ e
 
 -- case: recv truncates a datagram larger then the buffer of an explicit size
 sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
+fiber.yield()
 received_message = receiving_socket:recv(512)
 e = receiving_socket:errno()
 received_message == message:sub(1, 512) -- expected true
@@ -872,6 +885,7 @@ message = string.rep('y', message_len)
 
 -- case: recvfrom truncates a datagram larger then the buffer of an explicit size
 sending_socket:sendto('127.0.0.1', receiving_socket_port, message)
+fiber.yield()
 received_message, from = receiving_socket:recvfrom(512)
 e = receiving_socket:errno()
 received_message == message:sub(1, 512) -- expected true
-- 
2.17.1