YJIT: Disable code GC (#8865)

Co-authored-by: Alan Wu <alansi.xingwu@shopify.com>
Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>

1 files changed, 27 insertions, 4 deletions

diff --git a/test/ruby/test_yjit.rb b/test/ruby/test_yjit.rb
index 8adf50e271..132bb14a49 100644
--- a/test/ruby/test_yjit.rb
+++ b/test/ruby/test_yjit.rb
@@ -1058,8 +1058,30 @@ class TestYJIT < Test::Unit::TestCase
     RUBY
   end
 
+  def test_disable_code_gc_with_many_iseqs
+    assert_compiles(code_gc_helpers + <<~'RUBY', exits: :any, result: :ok, mem_size: 1, code_gc: false)
+      fiber = Fiber.new {
+        # Loop to call the same basic block again after Fiber.yield
+        while true
+          Fiber.yield(nil.to_i)
+        end
+      }
+
+      return :not_paged1 unless add_pages(250) # use some pages
+      return :broken_resume1 if fiber.resume != 0 # leave an on-stack code as well
+
+      add_pages(2000) # use a whole lot of pages to run out of 1MiB
+      return :broken_resume2 if fiber.resume != 0 # on-stack code should be callable
+
+      code_gc_count = RubyVM::YJIT.runtime_stats[:code_gc_count]
+      return :"code_gc_#{code_gc_count}" if code_gc_count != 0
+
+      :ok
+    RUBY
+  end
+
   def test_code_gc_with_many_iseqs
-    assert_compiles(code_gc_helpers + <<~'RUBY', exits: :any, result: :ok, mem_size: 1)
+    assert_compiles(code_gc_helpers + <<~'RUBY', exits: :any, result: :ok, mem_size: 1, code_gc: true)
       fiber = Fiber.new {
         # Loop to call the same basic block again after Fiber.yield
         while true
@@ -1425,7 +1447,7 @@ class TestYJIT < Test::Unit::TestCase
   end
 
   ANY = Object.new
-  def assert_compiles(test_script, insns: [], call_threshold: 1, stdout: nil, exits: {}, result: ANY, frozen_string_literal: nil, mem_size: nil)
+  def assert_compiles(test_script, insns: [], call_threshold: 1, stdout: nil, exits: {}, result: ANY, frozen_string_literal: nil, mem_size: nil, code_gc: false)
     reset_stats = <<~RUBY
       RubyVM::YJIT.runtime_stats
       RubyVM::YJIT.reset_stats!
@@ -1459,7 +1481,7 @@ class TestYJIT < Test::Unit::TestCase
       #{write_results}
     RUBY
 
-    status, out, err, stats = eval_with_jit(script, call_threshold:, mem_size:)
+    status, out, err, stats = eval_with_jit(script, call_threshold:, mem_size:, code_gc:)
 
     assert status.success?, "exited with status #{status.to_i}, stderr:\n#{err}"
 
@@ -1520,13 +1542,14 @@ class TestYJIT < Test::Unit::TestCase
     s.chars.map { |c| c.ascii_only? ? c : "\\u%x" % c.codepoints[0] }.join
   end
 
-  def eval_with_jit(script, call_threshold: 1, timeout: 1000, mem_size: nil)
+  def eval_with_jit(script, call_threshold: 1, timeout: 1000, mem_size: nil, code_gc: false)
     args = [
       "--disable-gems",
       "--yjit-call-threshold=#{call_threshold}",
       "--yjit-stats=quiet"
     ]
     args << "--yjit-exec-mem-size=#{mem_size}" if mem_size
+    args << "--yjit-code-gc" if code_gc
     args << "-e" << script_shell_encode(script)
     stats_r, stats_w = IO.pipe
     # Separate thread so we don't deadlock when