//! Stage 19: mremap, by running `remaptest` (a musl static PIE): growing in
//! place, shrinking, moving (MREMAP_MAYMOVE, MREMAP_FIXED), the errors, a
//! file mapping, copy-on-write after a move in a forked child, and musl's
//! realloc of big blocks.
#![no_std]
#![no_main]
#![feature(custom_test_frameworks)]
#![test_runner(rustbelt::test_runner)]
#![reexport_test_harness_main = "test_main"]

extern crate alloc;

use alloc::string::String;
use alloc::sync::Arc;
use alloc::vec::Vec;
use bootloader::{BootInfo, entry_point};
use core::panic::PanicInfo;
use rustbelt::fs::file::File;
use rustbelt::process::{self, ExitStatus, SpawnArgs};
use rustbelt::{fs, memory, thread};

entry_point!(main);

fn main(boot_info: &'static BootInfo) -> ! {
    rustbelt::init();
    rustbelt::init_memory(boot_info);
    rustbelt::init_smp(); // moves must shoot down other CPUs' TLB entries
    fs::init();
    rustbelt::init_storage();
    test_main();
    rustbelt::hlt_loop();
}

/// Run /mnt/disk0/bin/`name` with `args`; its exit status and stdout.
fn run(name: &str, args: &[&str]) -> (ExitStatus, String) {
    let (reader, writer) = fs::pipe::new();
    let mut spawn = SpawnArgs::kernel(name);
    spawn.args.extend(args.iter().map(|a| String::from(*a)));
    spawn.stdio[1] = Arc::new(writer);
    let p = process::spawn_path(&alloc::format!("/mnt/disk0/bin/{}", name), spawn).expect("spawn failed");
    let mut out = Vec::new();
    let mut buf = [0u8; 256];
    loop {
        match reader.read(&mut buf).unwrap() {
            0 => break,
            n => out.extend_from_slice(&buf[..n]),
        }
    }
    (process::wait(&p), String::from_utf8_lossy(&out).into_owned())
}

fn counts() -> (usize, usize, usize) {
    thread::sleep_ticks(3);
    (thread::thread_count(), process::count(), memory::frames_in_use())
}

/// remaptest passes, twice, and the second run leaves nothing behind.
#[test_case]
fn remaptest_passes() {
    let (status, out) = run("remaptest", &[]);
    assert_eq!(status, ExitStatus::Exited(0), "output: {}", out);
    let before = counts();
    let (status, out) = run("remaptest", &[]);
    assert_eq!(status, ExitStatus::Exited(0), "output: {}", out);
    assert!(out.contains("remaptest: all passed"), "output: {}", out);
    assert_eq!(counts(), before, "remaptest leaked something");
}

/// `--trace` knows the name.
#[test_case]
fn trace_name() {
    assert_eq!(rustbelt::syscall::trace_name(25), "mremap");
}

#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    rustbelt::test_panic_handler(info)
}