From 89484f5df095a4fb05afe40ce0328e33cf79e9aa Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Thu, 14 Nov 2024 17:13:58 +0100
Subject: [PATCH] Always close profiler output file.

Reported by Guilherme Batalheiro.

(cherry picked from commit fca66335d131669cf017420af6963a7565babb58)
---
 src/jit/p.lua                                 |  4 +--
 ...close-profile-dump-with-0-samples.test.lua | 25 +++++++++++++++++++
 .../script.lua                                | 14 +++++++++++
 test/tarantool-tests/utils/tools.lua          |  4 +++
 4 files changed, 44 insertions(+), 3 deletions(-)
 create mode 100644 test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples.test.lua
 create mode 100644 test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples/script.lua

diff --git a/src/jit/p.lua b/src/jit/p.lua
index 4569d69e9b..89b49584c4 100644
--- a/src/jit/p.lua
+++ b/src/jit/p.lua
@@ -228,9 +228,7 @@ local function prof_finish()
     local samples = prof_samples
     if samples == 0 then
       if prof_raw ~= true then out:write("[No samples collected]\n") end
-      return
-    end
-    if prof_ann then
+    elseif prof_ann then
       prof_annotate(prof_count1, samples)
     else
       prof_top(prof_count1, prof_count2, samples, "")
diff --git a/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples.test.lua b/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples.test.lua
new file mode 100644
index 0000000000..bdee9f2647
--- /dev/null
+++ b/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples.test.lua
@@ -0,0 +1,25 @@
+local tap = require('tap')
+local test = tap.test('lj-1304-close-profile-dump-with-0-samples'):skipcond({
+  ['Test requires /proc filesystem'] = jit.os == 'OSX',
+})
+local utils = require('utils')
+
+test:plan(1)
+
+local p_filename = '/tmp/profile'
+
+-- <makecmd> runs %testname%/script.lua by <LUAJIT_TEST_BINARY>
+-- with the given environment, launch options and CLI arguments.
+local script = utils.exec.makecmd(arg)
+-- Execute a Lua script with start and stop LuaJIT profiler,
+-- it is expected no samples found by profiler. The script's
+-- output is suppressed, it is not interested.
+local _ = script(p_filename)
+
+local p_content = io.open(p_filename):read('a*')
+test:is(utils.tools.trim(p_content), '[No samples collected]', 'profile dump has no samples')
+
+-- Teardown.
+os.remove(p_filename)
+
+test:done(true)
diff --git a/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples/script.lua b/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples/script.lua
new file mode 100644
index 0000000000..77335a0864
--- /dev/null
+++ b/test/tarantool-tests/lj-1304-close-profile-dump-with-0-samples/script.lua
@@ -0,0 +1,14 @@
+local p_options = 'ri1'
+local p_filename = assert(arg[1], 'filename argument is missing')
+
+require('jit.p').start(p_options, p_filename)
+
+-- No code to generate profiling samples.
+
+-- Stop profiler to execute `jit/p.lua:prof_fmt()`. With zero
+-- samples it triggers early return without closing the file.
+require('jit.p').stop()
+
+-- Make sure LuaJIT profiler is close a file handle.
+local ls_output = io.popen('ls -l /proc/$$/fd'):read('a*')
+assert(ls_output:find(p_filename) == nil, 'file is open')
diff --git a/test/tarantool-tests/utils/tools.lua b/test/tarantool-tests/utils/tools.lua
index 33fcae7899..9cb65daf18 100644
--- a/test/tarantool-tests/utils/tools.lua
+++ b/test/tarantool-tests/utils/tools.lua
@@ -21,4 +21,8 @@ function M.read_file(path)
   return content
 end
 
+function M.trim(str)
+  return (str:gsub('^%s*(.-)%s*$', '%1'))
+end
+
 return M