From 6d95fd5fb8097da33fa0a96c6a14e6199c64610a Mon Sep 17 00:00:00 2001
From: Jan-Erik Rediger <janerik@fnordig.de>
Date: Tue, 28 May 2024 12:49:26 +0200
Subject: [PATCH] pass data into thread

---
 backend/cmd/threads/main.ha                 |  7 ++++---
 backend/vendor/hare-thread/thread/thread.ha | 23 ++++++++++++++-------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/backend/cmd/threads/main.ha b/backend/cmd/threads/main.ha
index e73b8aa..02dbddf 100644
--- a/backend/cmd/threads/main.ha
+++ b/backend/cmd/threads/main.ha
@@ -2,13 +2,14 @@ use types::c;
 use fmt;
 use thread;
 
-fn thread_start() void = {
-	fmt::println("hello from another thread")!;
+fn thread_start(data: nullable *opaque) void = {
+	let arg = data: *u32;
+	fmt::printfln("hello from another thread. you sent: {}", *arg)!;
 };
 
 export fn main() void = {
 	fmt::println("starting a thread")!;
-	let tid = thread::spawn(&thread_start)!;
+	let tid = thread::spawn(&thread_start, &42)!;
 
 	fmt::println("joining")!;
 	thread::join(tid)!;
diff --git a/backend/vendor/hare-thread/thread/thread.ha b/backend/vendor/hare-thread/thread/thread.ha
index b0b51ad..3b94830 100644
--- a/backend/vendor/hare-thread/thread/thread.ha
+++ b/backend/vendor/hare-thread/thread/thread.ha
@@ -3,15 +3,21 @@ use types::c;
 export type pthread_t = [8]u8;
 type pthread_attr_t = opaque;
 type pthread_fn = fn(nullable *opaque) nullable *opaque;
-export type thread_fn = fn() void;
+export type thread_fn = fn(nullable *opaque) void;
 
 @symbol("pthread_create") fn pthread_create(thread: nullable *pthread_t, attr: nullable *pthread_attr_t, start_routine: *pthread_fn, arg: nullable *opaque) int;
 @symbol("pthread_join") fn pthread_join(thread: pthread_t, nullable *nullable *opaque) int;
 @symbol("pthread_detach") fn pthread_detach(thread: pthread_t) int;
 
-fn thread_spawn_wrapper(data: nullable *opaque) nullable *opaque = {
-	let f = data: *thread_fn;
-	f();
+type data_wrapper = struct {
+	f: *thread_fn,
+	data: nullable *opaque,
+};
+
+fn thread_spawn_wrapper(arg: nullable *opaque) nullable *opaque = {
+	let data = arg: *data_wrapper;
+	data.f(data.data);
+	free(data);
 	return null;
 };
 
@@ -23,11 +29,14 @@ export type join_handle = struct {
 // spawn a thread
 //
 // returns a handle or an error
-export fn spawn(f: *thread_fn) (join_handle | error) = {
-	let data = f: *opaque;
+export fn spawn(f: *thread_fn, data: nullable *opaque) (join_handle | error) = {
+	let data: *data_wrapper = alloc(data_wrapper {
+		f = f,
+		data = data,
+	});
 
 	let tid: pthread_t = [0...];
-	let ret = pthread_create(&tid, null, &thread_spawn_wrapper, f);
+	let ret = pthread_create(&tid, null, &thread_spawn_wrapper, data);
 	if (ret != 0) {
 		return error;
 	};