Add number of call frame check

Author: kateinoigakukun

benchmarks/vm_deep_call.rb

@@ -0,0 +1,55 @@
+# This script checks the max number of call frames under WebAssembly restriction
+#
+# Example runs
+# $ ruby vm_deep_call.rb
+# $ RUBY_EXE="wasmtime run --mapdir /::/ head-wasm32-unknown-wasi-minimal/usr/local/bin/ruby --" ruby vm_deep_call.rb
+# $ RUBY_EXE="wasmtime run --env RUBY_FIBER_MACHINE_STACK_SIZE=20971520 --mapdir /::/ head-wasm32-unknown-wasi-minimal/usr/local/bin/ruby --" ruby vm_deep_call.rb
+
+def vm_rec n
+  vm_rec n - 1 if n > 0
+end
+
+def vm_c_rec n
+  1.times do
+    vm_c_rec n - 1 if n > 0
+  end
+end
+
+def vm_rec_fiber n
+  Fiber.new { vm_rec n }.resume
+end
+
+def vm_c_rec_fiber n
+  Fiber.new { vm_c_rec n }.resume
+end
+
+def check(ruby_exe, target, n)
+  cmd = %Q(#{ruby_exe} -r #{File.expand_path(__FILE__)} -e "#{target}(#{n})")
+  Kernel.system(cmd, err: File::NULL)
+end
+
+def bisect(ruby_exe, target)
+  min = 0
+  max = 15000
+  while min < max
+    mid = (min + max) / 2
+    ok = check(ruby_exe, target, mid)
+    if ok
+      min = mid + 1
+    else
+      max = mid
+    end
+  end
+  min
+end
+
+def main
+  ruby_exe = ENV['RUBY_EXE'] || 'ruby'
+  puts "How deep the call stack can be"
+  puts "  with only VM calls:           " + bisect(ruby_exe, "vm_rec").to_s
+  puts "  with only VM calls in Fiber:  " + bisect(ruby_exe, "vm_rec_fiber").to_s
+  puts "  with VM and C calls:          " + bisect(ruby_exe, "vm_c_rec").to_s
+  puts "  with VM and C calls in Fiber: " + bisect(ruby_exe, "vm_c_rec_fiber").to_s
+end
+
+main if $0 == __FILE__