danos/system/services/process-test/process-test.zig

105 lines
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Zig

//! process-test — a test fixture for process management (bundled in the
//! initial-ramdisk, driven by the `supervision` test case). One binary, three
//! roles picked by argv, so the whole user-side surface is exercised end to end:
//!
//! - `process-test run` — the supervisor: spawns the two children below with an
//! exit-notification endpoint, sees them in `process_enumerate`, kills them,
//! receives both exit notifications, and confirms they are gone. Prints
//! "process-test: ok" for the kernel test to match, or a FAIL line naming the
//! step that broke.
//! - `process-test sleeper` — a child that blocks in `sleep` forever: its kill
//! exercises the immediate reap of a blocked task.
//! - `process-test spinner` — a child that spins in user mode making no system
//! calls: its kill exercises the deferred path (kill_pending, finished by the
//! timer tick).
//!
//! Spawned with no arguments (the initial-ramdisk sweep test starts every bundled
//! binary bare), it exits silently so it cannot derange other tests' output.
const std = @import("std");
const runtime = @import("runtime");
fn fail(step: []const u8) noreturn {
_ = runtime.system.write("process-test: FAIL ");
_ = runtime.system.write(step);
_ = runtime.system.write("\n");
runtime.system.exit(1);
}
/// Whether process `id` appears in a fresh `process_enumerate` snapshot, named
/// `name` (an id present under the wrong name is a table mix-up, not a pass).
fn listed(id: u32, name: []const u8) bool {
var table: [32]runtime.system.ProcessDescriptor = undefined;
const total = runtime.system.processes(&table);
for (table[0..@min(total, table.len)]) |descriptor| {
if (descriptor.id != id) continue;
return std.mem.eql(u8, descriptor.name[0..descriptor.name_length], name);
}
return false;
}
/// Block on the exit endpoint until a child-exit notification arrives; returns
/// the ended child's id. A wrong wake-up (there should be none — nothing else
/// knows this endpoint) fails the test rather than looping forever.
fn awaitChildExit(endpoint: runtime.ipc.Handle) u32 {
var scratch: [8]u8 = undefined;
const received = runtime.ipc.replyWait(endpoint, scratch[0..0], &scratch, null);
if (!received.isChildExit()) fail("expected a child-exit notification");
return received.childProcessId();
}
pub fn main(init: runtime.process.Init) void {
const role = init.arguments.get(1) orelse return; // spawned bare (ramdisk sweep): stay silent
if (std.mem.eql(u8, role, "sleeper")) {
while (true) runtime.system.sleep(500);
}
if (std.mem.eql(u8, role, "spinner")) {
var beat: u64 = 0;
const touch: *volatile u64 = &beat;
while (true) touch.* +%= 1; // user mode only — no system calls to die at
}
// The supervisor ("run").
const endpoint = runtime.ipc.createIpcEndpoint() orelse fail("create exit endpoint");
const sleeper = runtime.system.spawnSupervised("process-test", &.{"sleeper"}, endpoint) orelse fail("spawn sleeper");
const spinner = runtime.system.spawnSupervised("process-test", &.{"spinner"}, endpoint) orelse fail("spawn spinner");
runtime.system.sleep(100); // let the sleeper block and the spinner get a core
if (!listed(sleeper, "process-test")) fail("sleeper not in process_enumerate");
if (!listed(spinner, "process-test")) fail("spinner not in process_enumerate");
// Kills that must be refused: a kernel task (id 0), and an id that was never
// issued — both -ESRCH. (-EPERM needs a second supervisor; the kernel-level
// `process-kill` test covers it.)
if (runtime.system.kill(0)) fail("killing a kernel task was allowed");
if (runtime.system.kill(0xFFFF_FFF0)) fail("killing an unknown id was allowed");
// The blocked child: usually reaped on the spot (it sits in `sleep`). The
// notification is the fence — after it, the child is certainly gone, so the
// second kill must miss (its id is never reused).
if (!runtime.system.kill(sleeper)) fail("kill sleeper");
if (awaitChildExit(endpoint) != sleeper) fail("sleeper exit notification");
if (runtime.system.kill(sleeper)) fail("double kill was allowed");
// The running child: the deferred path — condemned now, dead by the next tick.
if (!runtime.system.kill(spinner)) fail("kill spinner");
if (awaitChildExit(endpoint) != spinner) fail("spinner exit notification");
if (listed(sleeper, "process-test")) fail("sleeper still listed after kill");
if (listed(spinner, "process-test")) fail("spinner still listed after kill");
// M17.2: both children were killed by us, and the reason says so — the whole
// restart-policy input, read through the runtime like a real supervisor would.
if ((runtime.process.exitReason(sleeper) orelse .exited) != .killed) fail("sleeper reason not killed");
if ((runtime.process.exitReason(spinner) orelse .exited) != .killed) fail("spinner reason not killed");
if (runtime.process.exitReason(0xFFFF_FFF0) != null) fail("unknown id had a reason");
_ = runtime.system.write("process-test: ok\n");
}
pub const panic = runtime.panic;
comptime {
_ = &runtime.start._start; // pull the runtime entry shim into the image
}