[Tarantool-patches] [PATCHv4 2/3] test: add separated module for proccess operations with timeout

[Artem Starshov]

Functions with timeout transferred to module test/app-tap/lua/process_timeout.lua
for further using in other tests.
(from test/app-tap/gh-4983-tnt-e-assert-false-hangs.test.lua)

Follows up #4983
---
 test/app-tap/lua/process_timeout.lua | 59 ++++++++++++++++++++++++++++
 test/app-tap/suite.ini               |  2 +-
 2 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 test/app-tap/lua/process_timeout.lua

diff --git a/test/app-tap/lua/process_timeout.lua b/test/app-tap/lua/process_timeout.lua
new file mode 100644
index 000000000..1ca3636b9
--- /dev/null
+++ b/test/app-tap/lua/process_timeout.lua
@@ -0,0 +1,59 @@
+local fiber = require('fiber')
+local clock = require('clock')
+local ffi = require('ffi')
+local fio = require('fio')
+local errno = require('errno')
+
+-- For process_is_alive.
+ffi.cdef([[
+    int kill(pid_t pid, int sig);
+]])
+
+--- Verify whether a process is alive.
+local function process_is_alive(pid)
+    local rc = ffi.C.kill(pid, 0)
+    return rc == 0 or errno() ~= errno.ESRCH
+end
+
+--- Returns true if process completed before timeout, false otherwise.
+local function wait_process_completion(pid, timeout)
+    local start_time = clock.monotonic()
+    local process_completed = false
+    while clock.monotonic() - start_time < timeout do
+        if not process_is_alive(pid) then
+            process_completed = true
+            break
+        end
+        fiber.sleep(0.01)
+    end
+    return process_completed
+end
+
+--- Open file on reading with timeout.
+local function open_with_timeout(filename, timeout)
+    local fh
+    local start_time = clock.monotonic()
+    while not fh and clock.monotonic() - start_time < timeout do
+        fh = fio.open(filename, {'O_RDONLY'})
+        fiber.sleep(0.01)
+    end
+    return fh
+end
+
+--- Try to read from file with timeout with interval.
+local function read_with_timeout(fh, timeout, interval)
+    local data = ''
+    local start_time = clock.monotonic()
+    while #data == 0 and clock.monotonic() - start_time < timeout do
+        data = fh:read()
+        if #data == 0 then fiber.sleep(interval) end
+    end
+    return data
+end
+
+return {
+    process_is_alive = process_is_alive,
+    wait_process_completion = wait_process_completion,
+    open_with_timeout = open_with_timeout,
+    read_with_timeout = read_with_timeout
+}
diff --git a/test/app-tap/suite.ini b/test/app-tap/suite.ini
index 2f16128f9..6e27f88d6 100644
--- a/test/app-tap/suite.ini
+++ b/test/app-tap/suite.ini
@@ -1,7 +1,7 @@
 [default]
 core = app
 description = application server tests (TAP)
-lua_libs = lua/require_mod.lua lua/serializer_test.lua
+lua_libs = lua/require_mod.lua lua/serializer_test.lua lua/process_timeout.lua
 is_parallel = True
 pretest_clean = True
 use_unix_sockets_iproto = True
-- 
2.28.0