Fix benchmark code and add C level result (#243)

tests/ffi/README.md

@@ -64,6 +64,11 @@ Command: `cargo run --profile=release run tests/ffi/benchmark/external_call`
 
   > Commit: ddf0c4c
 
+**C**
+
+- Device1-Linux-PVE: 0.001949 (sec)
+  > gcc (GCC) 14.2.1 20240910
+
 **LuaJit ffi**
 
 Command: `luajit tests/ffi/benchmark/external_call/luajit.lua`

tests/ffi/benchmark/external_call/init.luau

@@ -1,11 +1,11 @@
 local ffi = require("@lune/ffi")
-local lib = require("../../utility/compile")("./tests/ffi/benchmark/external_call/lib.c")
+local lib = require("../../utils/compile")("./tests/ffi/benchmark/external_call/lib.c")
 local process = require("@lune/process")
 local c = ffi.c
 local BENCH_SCALE: number = tonumber(process.env.BENCH_SCALE) or 1000000
 
 -- Get clock provider
-local procClock = require("../../utility/proc_clock")
+local procClock = require("../../utils/proc_clock")
 local before, after = procClock.newBox()
 local getClock = procClock.getClock
 
@@ -22,6 +22,10 @@ for i = 1, BENCH_SCALE do
 end
 getClock(after)
 
-print(procClock.getOffset(before, after))
+print("lune-std-ffi: " .. procClock.getOffset(before, after))
 local result = c.int:readData(a)
 assert(result == BENCH_SCALE, `bench_add failed. result expected {BENCH_SCALE}, got {result}`)
+
+local cSideTime = ffi.box(ffi.f64.size)
+c.fn({}, ffi.f64):callable(lib:find("c_test"))(cSideTime)
+print("C level: " .. ffi.f64:readData(cSideTime))

tests/ffi/benchmark/external_call/lib.c

@@ -1,4 +1,18 @@
+#include <time.h>
 
 int add(int a, int b) {
     return a + b;
 }
+
+double c_test() {
+    clock_t before = clock();
+
+    int a = 0;
+    for (int i=0; i<1000000; i++) {
+        a = add(a, 1);
+    }
+
+    clock_t after = clock();
+
+    return (double)(after - before) / CLOCKS_PER_SEC;
+}