1 files changed, 289 insertions, 0 deletions
diff --git a/test/-ext-/thread/test_instrumentation_api.rb b/test/-ext-/thread/test_instrumentation_api.rb
new file mode 100644
index 0000000000..663e41be53
--- /dev/null
+++ b/test/-ext-/thread/test_instrumentation_api.rb
@@ -0,0 +1,289 @@
+# frozen_string_literal: false
+require 'envutil'
+require_relative "helper"
+
+class TestThreadInstrumentation < Test::Unit::TestCase
+  include ThreadInstrumentation::TestHelper
+
+  def setup
+    pend("No windows support") if /mswin|mingw|bccwin/ =~ RUBY_PLATFORM
+
+    require '-test-/thread/instrumentation'
+
+    cleanup_threads
+  end
+
+  def teardown
+    return if /mswin|mingw|bccwin/ =~ RUBY_PLATFORM
+    Bug::ThreadInstrumentation.unregister_callback
+    cleanup_threads
+  end
+
+  THREADS_COUNT = 3
+
+  def test_single_thread_timeline
+    thread = nil
+    full_timeline = record do
+      thread = Thread.new { 1 + 1 }
+      thread.join
+    end
+    assert_equal %i(started ready resumed suspended exited), timeline_for(thread, full_timeline)
+  ensure
+    thread&.kill
+  end
+
+  def test_thread_pass_single_thread
+    full_timeline = record do
+      Thread.pass
+    end
+    assert_equal [], timeline_for(Thread.current, full_timeline)
+  end
+
+  def test_thread_pass_multi_thread
+    thread = Thread.new do
+      cpu_bound_work(0.5)
+    end
+
+    full_timeline = record do
+      Thread.pass
+    end
+
+    assert_equal %i(suspended ready resumed), timeline_for(Thread.current, full_timeline)
+  ensure
+    thread&.kill
+    thread&.join
+  end
+
+  def test_multi_thread_timeline
+    threads = nil
+    full_timeline = record do
+      threads = threaded_cpu_bound_work(1.0)
+      results = threads.map(&:value)
+      results.each do |r|
+        refute_equal false, r
+      end
+      assert_equal [false] * THREADS_COUNT, threads.map(&:status)
+    end
+
+    threads.each do |thread|
+      timeline = timeline_for(thread, full_timeline)
+      assert_consistent_timeline(timeline)
+      assert_operator timeline.count(:suspended), :>=, 1, "Expected threads to yield suspended at least once: #{timeline.inspect}"
+    end
+
+    timeline = timeline_for(Thread.current, full_timeline)
+    assert_consistent_timeline(timeline)
+  ensure
+    threads&.each(&:kill)
+  end
+
+  def test_join_suspends # Bug #18900
+    thread = other_thread = nil
+    full_timeline = record do
+      other_thread = Thread.new { sleep 0.3 }
+      thread = Thread.new { other_thread.join }
+      thread.join
+    end
+
+    timeline = timeline_for(thread, full_timeline)
+    assert_consistent_timeline(timeline)
+    assert_equal %i(started ready resumed suspended ready resumed suspended exited), timeline
+  ensure
+    other_thread&.kill
+    thread&.kill
+  end
+
+  def test_io_release_gvl
+    r, w = IO.pipe
+    thread = nil
+    full_timeline = record do
+      thread = Thread.new do
+        w.write("Hello\n")
+      end
+      thread.join
+    end
+
+    timeline = timeline_for(thread, full_timeline)
+    assert_consistent_timeline(timeline)
+    assert_equal %i(started ready resumed suspended ready resumed suspended exited), timeline
+  ensure
+    r&.close
+    w&.close
+  end
+
+  def test_queue_releases_gvl
+    queue1 = Queue.new
+    queue2 = Queue.new
+
+    thread = nil
+
+    full_timeline = record do
+      thread = Thread.new do
+        queue1 << true
+        queue2.pop
+      end
+
+      queue1.pop
+      queue2 << true
+      thread.join
+    end
+
+    timeline = timeline_for(thread, full_timeline)
+    assert_consistent_timeline(timeline)
+    assert_equal %i(started ready resumed suspended ready resumed suspended exited), timeline
+  end
+
+  def test_blocking_on_ractor
+    assert_ractor(<<-"RUBY", require_relative: "helper", require: "-test-/thread/instrumentation")
+      include ThreadInstrumentation::TestHelper
+
+      ractor = Ractor.new {
+        Ractor.receive # wait until woke
+        Thread.current
+      }
+
+      # Wait for the main thread to block, then wake the ractor
+      Thread.new do
+        while Thread.main.status != "sleep"
+          Thread.pass
+        end
+        ractor.send true
+      end
+
+      full_timeline = record do
+        ractor.take
+      end
+
+      timeline = timeline_for(Thread.current, full_timeline)
+      assert_consistent_timeline(timeline)
+      assert_equal %i(suspended ready resumed), timeline
+    RUBY
+  end
+
+  def test_sleeping_inside_ractor
+    assert_ractor(<<-"RUBY", require_relative: "helper", require: "-test-/thread/instrumentation")
+      include ThreadInstrumentation::TestHelper
+
+      thread = nil
+
+      full_timeline = record do
+        thread = Ractor.new{
+          sleep 0.1
+          Thread.current
+        }.take
+        sleep 0.1
+      end
+
+      timeline = timeline_for(thread, full_timeline)
+      assert_consistent_timeline(timeline)
+      assert_equal %i(started ready resumed suspended ready resumed suspended exited), timeline
+    RUBY
+  end
+
+  def test_thread_blocked_forever_on_mutex
+    mutex = Mutex.new
+    mutex.lock
+    thread = nil
+
+    full_timeline = record do
+      thread = Thread.new do
+        mutex.lock
+      end
+      10.times { Thread.pass }
+      sleep 0.1
+    end
+
+    mutex.unlock
+    thread.join
+
+    timeline = timeline_for(thread, full_timeline)
+    assert_consistent_timeline(timeline)
+    assert_equal %i(started ready resumed suspended), timeline
+  end
+
+  def test_thread_blocked_temporarily_on_mutex
+    mutex = Mutex.new
+    mutex.lock
+    thread = nil
+
+    full_timeline = record do
+      thread = Thread.new do
+        mutex.lock
+      end
+      10.times { Thread.pass }
+      sleep 0.1
+      mutex.unlock
+      10.times { Thread.pass }
+      sleep 0.1
+    end
+
+    thread.join
+
+    timeline = timeline_for(thread, full_timeline)
+    assert_consistent_timeline(timeline)
+    assert_equal %i(started ready resumed suspended ready resumed suspended exited), timeline
+  end
+
+  def test_thread_instrumentation_fork_safe
+    skip "No fork()" unless Process.respond_to?(:fork)
+
+    thread_statuses = full_timeline = nil
+    IO.popen("-") do |read_pipe|
+      if read_pipe
+        thread_statuses = Marshal.load(read_pipe)
+        full_timeline = Marshal.load(read_pipe)
+      else
+        threads = threaded_cpu_bound_work.each(&:join)
+        Marshal.dump(threads.map(&:status), STDOUT)
+        full_timeline = Bug::ThreadInstrumentation.unregister_callback.map { |t, e| [t.to_s, e ] }
+        Marshal.dump(full_timeline, STDOUT)
+      end
+    end
+    assert_predicate $?, :success?
+
+    assert_equal [false] * THREADS_COUNT, thread_statuses
+    thread_names = full_timeline.map(&:first).uniq
+    thread_names.each do |thread_name|
+      assert_consistent_timeline(timeline_for(thread_name, full_timeline))
+    end
+  end
+
+  def test_thread_instrumentation_unregister
+    assert Bug::ThreadInstrumentation::register_and_unregister_callbacks
+  end
+
+  private
+
+  def fib(n = 30)
+    return n if n <= 1
+    fib(n-1) + fib(n-2)
+  end
+
+  def cpu_bound_work(duration)
+    deadline = Process.clock_gettime(Process::CLOCK_MONOTONIC) + duration
+    i = 0
+    while deadline > Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      fib(25)
+      i += 1
+    end
+    i > 0 ? i : false
+  end
+
+  def threaded_cpu_bound_work(duration = 0.5)
+    THREADS_COUNT.times.map do
+      Thread.new do
+        cpu_bound_work(duration)
+      end
+    end
+  end
+
+  def cleanup_threads
+    Thread.list.each do |thread|
+      if thread != Thread.current
+        thread.kill
+        thread.join rescue nil
+      end
+    end
+    assert_equal [Thread.current], Thread.list
+  end
+end