Luajit 2.1 corountine vs function call comparision

luajit_coroutine_vs_func.lua

-- Testing coroutine overhead in LuaJIT 2.1 with NPL runtime
--[[ 
Starting function test...
memory(KB):	0.35546875
Functions:	500000
Elapsed time:	0	 s
Starting coroutine test...
memory(KB):	13781.81640625
Coroutines:	500000
Elapsed time:	0.191	 s
Starting single coroutine test...
memory(KB):	0.4453125
Coroutines:	500000
Elapsed time:	0.02800000000002

conclusions:
1. memory overhead: 0.26KB per coroutine
2. yield/resume pair overhead: 0.0004 ms

if you have 1000 objects each is calling yield/resume at 60FPS, then the time overhead is 0.2*1000/500000*60*1000 = 24ms
and if you do not reuse coroutine, then memory overhead is 1000*60*0.26 = 15.6MB/sec
]]

local total = 500000
local start, stop
function loopy(n)
  n = n + 1 
  return n
end

print "Starting function test..."
collectgarbage("collect");collectgarbage("collect");collectgarbage("collect");
local beforeCount =collectgarbage("count")
start = os.clock()
for i = 1, total do
  loopy(i)
end
stop = os.clock()
print("memory(KB):", collectgarbage("count") - beforeCount)
print("Functions:", total)
print("Elapsed time:", stop-start, " s")

print "Starting coroutine test..."
collectgarbage("collect");collectgarbage("collect");collectgarbage("collect");
local beforeCount =collectgarbage("count")
start = os.clock()
for i = 1, total do
  co = coroutine.create(loopy)
  coroutine.resume(co, i)
end
stop = os.clock()
print("memory(KB):", collectgarbage("count") - beforeCount)
print("Coroutines:", total)
print("Elapsed time:", stop-start, " s")


print "Starting single coroutine test..."
collectgarbage("collect");collectgarbage("collect");collectgarbage("collect");
local beforeCount =collectgarbage("count")
start = os.clock()
co = coroutine.create(function()
    for i = 1, total do
      loopy(i)
      coroutine.yield();
    end
end)

for i = 1, total do
  coroutine.resume(co, i)
end

stop = os.clock()
print("memory(KB):", collectgarbage("count") - beforeCount)
print("Coroutines:", total)
print("Elapsed time:", stop-start, " s")