From 00d284215c7b268d42109d259a947da079c6f057 Mon Sep 17 00:00:00 2001
From: flysand7 <thebumboni@gmail.com>
Date: Wed, 6 Sep 2023 07:55:45 +1100
Subject: [PATCH] Make thread handle a pointer to TCB on linux

---
 include/cia/sync.h        | 1 +
 include/tinyrt.h          | 1 -
 os/linux/tinyrt-threads.c | 6 +++++-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/cia/sync.h b/include/cia/sync.h
index 4eb436a..330a2f9 100644
--- a/include/cia/sync.h
+++ b/include/cia/sync.h
@@ -15,3 +15,4 @@ struct Cia_Mutex {
 void cia_mutex_init(Cia_Mutex *mutex);
 void cia_mutex_lock(Cia_Mutex *mutex);
 void cia_mutex_unlock(Cia_Mutex *mutex);
+
diff --git a/include/tinyrt.h b/include/tinyrt.h
index 09d85eb..6212855 100644
--- a/include/tinyrt.h
+++ b/include/tinyrt.h
@@ -51,7 +51,6 @@ _Noreturn static void _rt_program_exit(int code);
 // Thread API
 struct _RT_Thread typedef _RT_Thread;
 struct _RT_Thread {
-    u64 tid;
     void *handle;
 };
 static _RT_Status _rt_thread_current(_RT_Thread *thread);
diff --git a/os/linux/tinyrt-threads.c b/os/linux/tinyrt-threads.c
index fc03e51..9e53b41 100644
--- a/os/linux/tinyrt-threads.c
+++ b/os/linux/tinyrt-threads.c
@@ -10,7 +10,8 @@ extern i64 _cia_start_thread(
 );
 
 static _RT_Status _rt_thread_current(_RT_Thread *thread) {
-    return _RT_ERROR_NOT_IMPLEMENTED;
+    thread->handle = (void *)((u64)__builtin_frame_address(0) & ~(cia_stack_size - 1));
+    return _RT_STATUS_OK;
 }
 
 static _RT_Status _rt_thread_create(_RT_Thread *thread, int (*thread_fn)(void *ctx), void *ctx) {
@@ -29,6 +30,9 @@ static _RT_Status _rt_thread_create(_RT_Thread *thread, int (*thread_fn)(void *c
     for(int i = 0; i < cia_tls_image_size; ++i) {
         tls_base[i] = ((u8 *)cia_tls_image_base)[i];
     }
+    // Initialize the _RT_Thread handle, which would point to
+    // the TCB
+    thread->handle = tcb;
     // Create the new thread
     u64 flags = 0;
     // flags |= CLONE_CHILD_CLEARTID;