ladybird/Userland/Utilities/allocate.cpp
2021-11-27 11:14:16 +01:00

105 lines
2.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Optional.h>
#include <AK/String.h>
#include <LibCore/ElapsedTimer.h>
#include <LibMain/Main.h>
#include <unistd.h>
static void usage()
{
warnln("usage: allocate [number [unit (B/KiB/MiB)]]");
exit(1);
}
enum class Unit {
Bytes,
KiB,
MiB,
};
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
int count = 50;
auto unit = Unit::MiB;
if (arguments.argc >= 2) {
auto number = arguments.strings[1].to_uint();
if (!number.has_value()) {
usage();
}
count = number.value();
}
if (arguments.argc >= 3) {
if (arguments.strings[2] == "B")
unit = Unit::Bytes;
else if (arguments.strings[2] == "KiB")
unit = Unit::KiB;
else if (arguments.strings[2] == "MiB")
unit = Unit::MiB;
else
usage();
}
switch (unit) {
case Unit::Bytes:
break;
case Unit::KiB:
count *= KiB;
break;
case Unit::MiB:
count *= MiB;
break;
}
outln("allocating memory ({} bytes)...", count);
auto timer = Core::ElapsedTimer::start_new();
char* ptr = (char*)malloc(count);
if (!ptr) {
outln("failed.");
return 1;
}
outln("done in {}ms", timer.elapsed());
auto pages = count / PAGE_SIZE;
auto step = pages / 10;
outln("writing one byte to each page of allocated memory...");
timer.start();
auto timer2 = Core::ElapsedTimer::start_new();
for (int i = 0; i < pages; ++i) {
ptr[i * PAGE_SIZE] = 1;
if (i != 0 && (i % step) == 0) {
auto ms = timer2.elapsed();
if (ms == 0)
ms = 1;
auto bps = double(step * PAGE_SIZE) / (double(ms) / 1000);
outln("step took {}ms ({}MiB/s)", ms, bps / MiB);
timer2.start();
}
}
outln("done in {}ms", timer.elapsed());
outln("sleeping for ten seconds...");
for (int i = 0; i < 10; i++) {
outln("{}", i);
sleep(1);
}
outln("done.");
outln("freeing memory...");
timer.start();
free(ptr);
outln("done in {}ms", timer.elapsed());
return 0;
}