Merge pull request #9 from Meziu/feature/pthread-threads

Add back threading support and implement extensions

Author: Meziu

Cargo.toml

@@ -8,4 +8,5 @@ edition = "2021"
 [dependencies]
 libc = "0.2.116"
 ctru-sys = { git = "https://github.com/Meziu/ctru-rs.git" }
-spin = { version = "0.9", default-features = false, features = ["rwlock", "std"] }
+spin = { version = "0.9", default-features = false, features = ["rwlock", "std"] }
+static_assertions = "1.0"

src/lib.rs

@@ -3,6 +3,8 @@
 #![allow(non_camel_case_types)]
 #![allow(clippy::missing_safety_doc)]
 
+use std::ptr;
+
 /// Call this somewhere to force Rust to link this module.
 /// The call doesn't need to execute, just exist.
 ///
@@ -13,48 +15,153 @@ pub fn init() {}
 
 #[no_mangle]
 pub unsafe extern "C" fn pthread_create(
-    _native: *mut libc::pthread_t,
-    _attr: *const libc::pthread_attr_t,
-    _f: extern "C" fn(_: *mut libc::c_void) -> *mut libc::c_void,
-    _value: *mut libc::c_void,
+    native: *mut libc::pthread_t,
+    attr: *const libc::pthread_attr_t,
+    entrypoint: extern "C" fn(_: *mut libc::c_void) -> *mut libc::c_void,
+    value: *mut libc::c_void,
 ) -> libc::c_int {
-    1
+    let attr = attr as *const PThreadAttr;
+
+    let stack_size = (*attr).stack_size.unwrap_or(libc::PTHREAD_STACK_MIN) as ctru_sys::size_t;
+
+    // If no priority value is specified, spawn with the same
+    // priority as the parent thread
+    let priority = (*attr).priority.unwrap_or_else(|| pthread_getpriority());
+
+    // If no affinity is specified, spawn on the default core (determined by
+    // the application's Exheader)
+    let affinity = (*attr).affinity.unwrap_or(-2);
+
+    extern "C" fn thread_start(main: *mut libc::c_void) {
+        unsafe {
+            Box::from_raw(main as *mut Box<dyn FnOnce() -> *mut libc::c_void>)();
+        }
+    }
+
+    // The closure needs a fat pointer (64 bits) to work since it captures a variable and is thus a
+    // trait object, but *mut void is only 32 bits. We need double indirection to pass along the
+    // full closure data.
+    // We make this closure in the first place because threadCreate expects a void return type, but
+    // entrypoint returns a pointer so the types are incompatible.
+    let main: *mut Box<dyn FnOnce() -> *mut libc::c_void> =
+        Box::into_raw(Box::new(Box::new(move || entrypoint(value))));
+
+    let handle = ctru_sys::threadCreate(
+        Some(thread_start),
+        main as *mut libc::c_void,
+        stack_size,
+        priority,
+        affinity,
+        false,
+    );
+
+    if handle.is_null() {
+        // There was some error, but libctru doesn't expose the result.
+        // We assume there was an incorrect parameter (such as too low of a priority).
+        // We also need to clean up the closure at this time.
+        drop(Box::from_raw(main));
+        return libc::EINVAL;
+    }
+
+    *native = handle as _;
+
+    0
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn pthread_join(
-    _native: libc::pthread_t,
+    native: libc::pthread_t,
     _value: *mut *mut libc::c_void,
 ) -> libc::c_int {
-    1
+    ctru_sys::threadJoin(native as ctru_sys::Thread, u64::MAX);
+    ctru_sys::threadFree(native as ctru_sys::Thread);
+
+    0
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn pthread_detach(_thread: libc::pthread_t) -> libc::c_int {
-    1
+pub unsafe extern "C" fn pthread_detach(thread: libc::pthread_t) -> libc::c_int {
+    ctru_sys::threadDetach(thread as ctru_sys::Thread);
+
+    0
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn pthread_attr_init(_attr: *mut libc::pthread_attr_t) -> libc::c_int {
-    1
+pub unsafe extern "C" fn pthread_getpriority() -> libc::c_int {
+    let mut priority = 0;
+    ctru_sys::svcGetThreadPriority(&mut priority, ctru_sys::CUR_THREAD_HANDLE);
+    priority
 }
 
+/// Internal struct for storing pthread attribute data
+/// Must be less than or equal to the size of `libc::pthread_attr_t`. We assert
+/// this below via static_assertions.
+struct PThreadAttr {
+    stack_size: Option<libc::size_t>,
+    priority: Option<libc::c_int>,
+    affinity: Option<libc::c_int>,
+}
+
+static_assertions::const_assert!(
+    std::mem::size_of::<PThreadAttr>() <= std::mem::size_of::<libc::pthread_attr_t>()
+);
+
 #[no_mangle]
-pub unsafe extern "C" fn pthread_attr_destroy(_attr: *mut libc::pthread_attr_t) -> libc::c_int {
-    1
+pub unsafe extern "C" fn pthread_attr_init(attr: *mut libc::pthread_attr_t) -> libc::c_int {
+    let attr = attr as *mut PThreadAttr;
+    *attr = PThreadAttr {
+        stack_size: None,
+        priority: None,
+        affinity: None,
+    };
+
+    0
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pthread_attr_destroy(attr: *mut libc::pthread_attr_t) -> libc::c_int {
+    ptr::drop_in_place(attr as *mut PThreadAttr);
+    0
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn pthread_attr_setstacksize(
-    _attr: *mut libc::pthread_attr_t,
-    _stack_size: libc::size_t,
+    attr: *mut libc::pthread_attr_t,
+    stack_size: libc::size_t,
+) -> libc::c_int {
+    let attr = attr as *mut PThreadAttr;
+    (*attr).stack_size = Some(stack_size);
+
+    0
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pthread_attr_setpriority(
+    attr: *mut libc::pthread_attr_t,
+    priority: libc::c_int,
 ) -> libc::c_int {
-    1
+    let attr = attr as *mut PThreadAttr;
+    (*attr).priority = Some(priority);
+
+    0
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn pthread_attr_setaffinity(
+    attr: *mut libc::pthread_attr_t,
+    affinity: libc::c_int,
+) -> libc::c_int {
+    let attr = attr as *mut PThreadAttr;
+    (*attr).affinity = Some(affinity);
+
+    0
 }
 
 #[no_mangle]
 pub unsafe extern "C" fn sched_yield() -> libc::c_int {
-    1
+    ctru_sys::svcSleepThread(0);
+
+    0
 }
 
 #[no_mangle]
@@ -407,7 +514,6 @@ pub unsafe extern "C" fn pthread_sigmask(
 
 use spin::rwlock::RwLock;
 use std::collections::BTreeMap;
-use std::ptr;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
 type Key = usize;