From bed08695a07ec915f21cd2f711518efe4a736730 Mon Sep 17 00:00:00 2001 From: Andrea Ciliberti Date: Sat, 15 Apr 2023 16:20:21 +0200 Subject: [PATCH] Refactor and suggestions --- src/lib.rs | 1 - src/misc.rs | 13 -- src/thread.rs | 345 --------------------------------------------- src/thread/attr.rs | 2 +- src/thread_keys.rs | 8 +- 5 files changed, 5 insertions(+), 364 deletions(-) delete mode 100644 src/misc.rs delete mode 100644 src/thread.rs diff --git a/src/lib.rs b/src/lib.rs index 653716a..8566726 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -2,6 +2,5 @@ #![allow(non_camel_case_types)] #![allow(clippy::missing_safety_doc)] -mod misc; mod thread; mod thread_keys; diff --git a/src/misc.rs b/src/misc.rs deleted file mode 100644 index 0ce81e4..0000000 --- a/src/misc.rs +++ /dev/null @@ -1,13 +0,0 @@ -//! Miscellaneous pthread functions - -// The implementation within `newlib` stubs this out *entirely*. It's not possible to use a "syscall". -/* -#[no_mangle] -pub unsafe extern "C" fn sched_yield() -> libc::c_int { - ctru_sys::svcSleepThread(0); - - 0 -} -*/ - -// `pthread_sigmask` and `pthread_atfork` are stubbed out by `newlib` \ No newline at end of file diff --git a/src/thread.rs b/src/thread.rs deleted file mode 100644 index c118fb9..0000000 --- a/src/thread.rs +++ /dev/null @@ -1,345 +0,0 @@ -//! PThread threads implemented using libctru. - -use spin::rwlock::RwLock; -use std::collections::BTreeMap; -use std::ptr; -use std::sync::atomic::{AtomicUsize, Ordering}; - -pub mod attr; - -/// The main thread's pthread ID -const MAIN_THREAD_ID: libc::pthread_t = 0; - -// We initialize to 1 since 0 is reserved for the main thread. -static NEXT_ID: AtomicUsize = AtomicUsize::new(1); - -// This is a spin-lock RwLock which yields the thread every loop. -static THREADS: RwLock, spin::Yield> = - RwLock::new(BTreeMap::new()); - -// Initialize to zero (main thread ID) since the main thread will have the -// default value in this thread local. -#[thread_local] -static mut THREAD_ID: libc::pthread_t = MAIN_THREAD_ID; - -#[derive(Copy, Clone)] -struct PThread { - thread: ShareablePtr, - os_thread_id: u32, - is_detached: bool, - is_finished: bool, - result: ShareablePtr, -} - -/// Pointers are not Send or Sync, though it's really just a lint. This struct -/// lets us ignore that "lint". -struct ShareablePtr(*mut T); -unsafe impl Send for ShareablePtr {} -unsafe impl Sync for ShareablePtr {} - -// We can't use the derives because they add an unnecessary T: Copy/Clone bound. -impl Copy for ShareablePtr {} -impl Clone for ShareablePtr { - fn clone(&self) -> Self { - *self - } -} - -#[no_mangle] -pub unsafe extern "C" fn __syscall_thread_create( - native: *mut libc::pthread_t, - entrypoint: extern "C" fn(_: *mut libc::c_void) -> *mut libc::c_void, - arg: *mut libc::c_void, - _stackaddr: *const libc::c_void, - stacksize: libc::size_t, -) -> libc::c_int { - let stack_size = stacksize; - // let priority = (*attr).schedparam.sched_priority; - let mut priority = 0; - let _ = ctru_sys::svcGetThreadPriority(&mut priority, ctru_sys::CUR_THREAD_HANDLE); - // let processor_id = (*attr).processor_id; - - let thread_id = NEXT_ID.fetch_add(1, Ordering::SeqCst) as libc::pthread_t; - - extern "C" fn thread_start(main: *mut libc::c_void) { - unsafe { - Box::from_raw(main as *mut Box)(); - } - } - - // 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 = Box::into_raw(Box::new(Box::new(move || { - THREAD_ID = thread_id; - - let result = entrypoint(arg); - - // Update the threads map with the result, and remove this thread if - // it's detached. - // We hold the lock the whole time so there isn't a race condition. - // (ex. we copy out the thread data, pthread_detach is called, we - // check is_detached and it's still false, so thread is never - // removed from the map) - let mut thread_map = THREADS.write(); - if let Some(mut pthread) = thread_map.get_mut(&thread_id) { - pthread.is_finished = true; - pthread.result.0 = result; - - if pthread.is_detached { - // libctru will call threadFree once this thread dies - thread_map.remove(&thread_id); - } - } - }))); - - let thread = ctru_sys::threadCreate( - Some(thread_start), - main as *mut libc::c_void, - stack_size as usize, - priority, - 0, // Normal CPU - false, - ); - - if thread.is_null() { - // There was some error, but libctru doesn't expose the result. - // We assume there was permissions issue (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::EPERM; - } - - // Get the OS thread ID - let os_handle = ctru_sys::threadGetHandle(thread); - let mut os_thread_id = 0; - let result = ctru_sys::svcGetThreadId(&mut os_thread_id, os_handle); - if ctru_sys::R_FAILED(result) { - // TODO: improve error handling? Different codes? - return libc::EPERM; - } - - // Insert the thread into our map - THREADS.write().insert( - thread_id, - PThread { - thread: ShareablePtr(thread), - os_thread_id, - is_detached: false, - is_finished: false, - result: ShareablePtr(ptr::null_mut()), - }, - ); - - *native = thread_id; - - 0 -} - -#[no_mangle] -pub unsafe extern "C" fn __syscall_thread_join( - thread_id: libc::pthread_t, -) -> *const libc::c_void { // The return value is returned as a pointer - if thread_id == MAIN_THREAD_ID { - // This is not a valid thread to join on - return std::ptr::null(); - } - - let thread_map = THREADS.read(); - let Some(&pthread) = thread_map.get(&thread_id) else { - // This is not a valid thread ID - return std::ptr::null(); - }; - // We need to drop our read guard so it doesn't stay locked while joining - // the thread. - drop(thread_map); - - if pthread.is_detached { - // Cannot join on a detached thread - return std::ptr::null(); - } - - let result = ctru_sys::threadJoin(pthread.thread.0, u64::MAX); - if ctru_sys::R_FAILED(result) { - // TODO: improve the error code by checking the result further? - return std::ptr::null(); - } - - ctru_sys::threadFree(pthread.thread.0); - let thread_data = THREADS.write().remove(&thread_id); - - // This should always be Some, but we use an if let just in case. - if let Some(thread_data) = thread_data { - return thread_data.result.0; - } - - std::ptr::null() -} - -#[no_mangle] -pub unsafe extern "C" fn __syscall_thread_detach(thread_id: libc::pthread_t) -> libc::c_int { - if thread_id == MAIN_THREAD_ID { - // This is not a valid thread to detach - return libc::EINVAL; - } - - let mut thread_map = THREADS.write(); - let Some(mut pthread) = thread_map.get_mut(&thread_id) else { - // This is not a valid thread ID - return libc::ESRCH - }; - - if pthread.is_detached { - // Cannot detach an already detached thread - return libc::EINVAL; - } - - pthread.is_detached = true; - ctru_sys::threadDetach(pthread.thread.0); - - if pthread.is_finished { - // threadFree was already called by threadDetach - thread_map.remove(&thread_id); - } - - 0 -} - -#[no_mangle] -pub unsafe extern "C" fn __syscall_thread_self() -> libc::pthread_t { - let thread_id = THREAD_ID; - - if thread_id == MAIN_THREAD_ID { - // Take this opportunity to populate the main thread's data in the map. - // They can only "legally" get the main thread's ID by calling this - // function, so this will run before they do anything that needs this. - - // We have to ignore the possible error from svcGetThreadId since - // pthread_self cannot fail... But there shouldn't be an error anyways. - let mut os_thread_id = 0; - let _ = ctru_sys::svcGetThreadId(&mut os_thread_id, ctru_sys::CUR_THREAD_HANDLE); - - THREADS.write().insert( - MAIN_THREAD_ID, - PThread { - // This null pointer is safe because we return before ever using - // it (in pthread_join and pthread_detach). - thread: ShareablePtr(ptr::null_mut()), - os_thread_id, - is_detached: true, - is_finished: false, - result: ShareablePtr(ptr::null_mut()), - }, - ); - } - - thread_id -} - -/// Closes a kernel handle on drop. -struct Handle(ctru_sys::Handle); - -impl TryFrom for Handle { - type Error = libc::c_int; - - fn try_from(thread_id: libc::pthread_t) -> Result { - let Some(&pthread) = THREADS.read().get(&thread_id) else { - // This is not a valid thread ID - return Err(libc::ESRCH) - }; - - if pthread.is_finished { - return Err(libc::ESRCH); - } - - let mut os_handle = 0; - let ret = unsafe { - ctru_sys::svcOpenThread( - &mut os_handle, - ctru_sys::CUR_PROCESS_HANDLE, - pthread.os_thread_id, - ) - }; - - if ctru_sys::R_FAILED(ret) || os_handle == u32::MAX { - // Either there was an error or the thread already finished - Err(libc::ESRCH) - } else { - Ok(Self(os_handle)) - } - } -} - -impl Drop for Handle { - fn drop(&mut self) { - unsafe { - // We ignore the error because we can't return it or panic. - let _ = ctru_sys::svcCloseHandle(self.0); - } - } -} - -#[no_mangle] -pub unsafe extern "C" fn pthread_getschedparam( - thread_id: libc::pthread_t, - policy: *mut libc::c_int, - param: *mut libc::sched_param, -) -> libc::c_int { - let handle = match Handle::try_from(thread_id) { - Ok(handle) => handle, - Err(code) => return code, - }; - - let mut priority = 0; - let result = ctru_sys::svcGetThreadPriority(&mut priority, handle.0); - if ctru_sys::R_FAILED(result) { - // Some error occurred. This is the only error defined for this - // function, so return it. Maybe the thread exited while this function - // was exiting? - return libc::ESRCH; - } - - (*param).sched_priority = priority; - - // SCHED_FIFO is closest to how the cooperative app core works, while - // SCHED_RR is closest to how the preemptive sys core works. - // However, we don't have an API to get the current processor ID of a chosen - // thread (only the current), so we just always return SCHED_FIFO. - (*policy) = libc::SCHED_FIFO; - - 0 -} - -#[no_mangle] -pub unsafe extern "C" fn pthread_setschedparam( - thread_id: libc::pthread_t, - policy: libc::c_int, - param: *const libc::sched_param, -) -> libc::c_int { - if policy != libc::SCHED_FIFO { - // We only accept SCHED_FIFO. See the note in pthread_getschedparam. - return libc::EINVAL; - } - - let handle = match Handle::try_from(thread_id) { - Ok(handle) => handle, - Err(code) => return code, - }; - - let result = ctru_sys::svcSetThreadPriority(handle.0, (*param).sched_priority); - if ctru_sys::R_FAILED(result) { - // Probably the priority is out of the permissible bounds - // TODO: improve the error code by checking the result further? - return libc::EPERM; - } - - 0 -} -/* -#[no_mangle] -pub unsafe extern "C" fn pthread_getprocessorid_np() -> libc::c_int { - ctru_sys::svcGetProcessorID() -} -*/ diff --git a/src/thread/attr.rs b/src/thread/attr.rs index cd05d9a..ce77055 100644 --- a/src/thread/attr.rs +++ b/src/thread/attr.rs @@ -28,4 +28,4 @@ pub unsafe extern "C" fn pthread_attr_setprocessorid_np( 0 } -*/ \ No newline at end of file +*/ diff --git a/src/thread_keys.rs b/src/thread_keys.rs index 006adbe..19ed1a1 100644 --- a/src/thread_keys.rs +++ b/src/thread_keys.rs @@ -20,7 +20,7 @@ fn is_valid_key(key: Key) -> bool { } #[no_mangle] -pub unsafe extern "C" fn __syscall_tls_create( +pub unsafe extern "C" fn __syscall_tls_create( key: *mut libc::pthread_key_t, destructor: Option, ) -> libc::c_int { @@ -33,7 +33,7 @@ pub unsafe extern "C" fn __syscall_tls_create( } #[no_mangle] -pub unsafe extern "C" fn __syscall_tls_delete(key: libc::pthread_key_t) -> libc::c_int { +pub unsafe extern "C" fn __syscall_tls_delete(key: libc::pthread_key_t) -> libc::c_int { match KEYS.write().remove(&(key as Key)) { // We had a entry, so it was a valid key. // It's officially undefined behavior if they use the key after this, @@ -46,7 +46,7 @@ pub unsafe extern "C" fn __syscall_tls_delete(key: libc::pthread_key_t) -> libc } #[no_mangle] -pub unsafe extern "C" fn __syscall_tls_get(key: libc::pthread_key_t) -> *mut libc::c_void { +pub unsafe extern "C" fn __syscall_tls_get(key: libc::pthread_key_t) -> *mut libc::c_void { if let Some(&value) = LOCALS.get(&(key as Key)) { value as _ } else { @@ -56,7 +56,7 @@ pub unsafe extern "C" fn __syscall_tls_get(key: libc::pthread_key_t) -> *mut li } #[no_mangle] -pub unsafe extern "C" fn __syscall_tls_set( +pub unsafe extern "C" fn __syscall_tls_set( key: libc::pthread_key_t, value: *const libc::c_void, ) -> libc::c_int {