split Process and Thread

docs/2_OSLab/g2/context.md

@@ -1,6 +1,6 @@
 # 上下文切换
 
-平台无关的代码位于 [kernel/src/process/context.rs](../../../kernel/src/process/context.rs) 中，而平台相关(aarch64)的代码位于 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs) 中。
+平台无关的代码位于 [kernel/src/process/context.rs](../../../kernel/src/process/structs.rs) 中，而平台相关(aarch64)的代码位于 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs) 中。
 
 ## 相关数据结构
 
@@ -56,7 +56,7 @@
     }
     ```
 
-    每个进程控制块 `Process` ([kernel/src/process/context.rs](../../../kernel/src/process/context.rs#L13)) 都会维护一个平台相关的 `Context` 对象，在 AArch64 中包含下列信息：
+    每个进程控制块 `Process` ([kernel/src/process/context.rs](../../../kernel/src/process/structs.rs#L13)) 都会维护一个平台相关的 `Context` 对象，在 AArch64 中包含下列信息：
 
     1. `stack_top`：内核栈顶地址
     2. `ttbr`：页表基址
@@ -64,7 +64,7 @@
 
 ## 切换流程
 
-在 [kernel/src/process/context.rs](../../../kernel/src/process/context.rs#L22) 里，`switch_to()` 是平台无关的切换函数，最终会调用 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs#L129) 里平台相关的切换函数 `Context::switch()`：
+在 [kernel/src/process/context.rs](../../../kernel/src/process/structs.rs#L22) 里，`switch_to()` 是平台无关的切换函数，最终会调用 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs#L129) 里平台相关的切换函数 `Context::switch()`：
 
 ```rust
 pub unsafe fn switch(&mut self, target: &mut Self) {
@@ -190,7 +190,7 @@ ret
 2. 创建新的**用户线程**：解析 ELF 文件。
 3. 从一个线程 **fork** 出一个新线程：通过 `fork` 系统调用。
 
-三种线程的平台无关创建流程实现在 [kernel/src/process/context.rs](../../../kernel/src/process/context.rs#L40) 里，最终会分别调用 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs#L146) 里的 `new_kernel_thread()`、`new_user_thread()` 和 `new_fork()` 这三个函数创建平台相关的 `Context` 结构。
+三种线程的平台无关创建流程实现在 [kernel/src/process/context.rs](../../../kernel/src/process/structs.rs#L40) 里，最终会分别调用 [kernel/src/arch/aarch64/interrupt/context.rs](../../../kernel/src/arch/aarch64/interrupt/context.rs#L146) 里的 `new_kernel_thread()`、`new_user_thread()` 和 `new_fork()` 这三个函数创建平台相关的 `Context` 结构。
 
 在这三个函数里，会构造 `ContextData` 与 `TrapFrame` 结构，构成一个 `InitStack`，并向新线程的内核栈压入 `InitStack` 结构，最后将新内核栈顶地址、页表基址等信息构成 `Context` 结构返回。这两个结构的构造方式如下：
 

kernel/src/process/mod.rs

@@ -1,11 +1,12 @@
-pub use self::context::Process;
+pub use self::structs::*;
 pub use rcore_thread::*;
 use crate::consts::{MAX_CPU_NUM, MAX_PROCESS_NUM};
 use crate::arch::cpu;
 use alloc::{boxed::Box, sync::Arc};
+use spin::MutexGuard;
 use log::*;
 
-pub mod context;
+pub mod structs;
 
 pub fn init() {
     // NOTE: max_time_slice <= 5 to ensure 'priority' test pass
@@ -14,7 +15,7 @@ pub fn init() {
 
     unsafe {
         for cpu_id in 0..MAX_CPU_NUM {
-            PROCESSORS[cpu_id].init(cpu_id, Process::new_init(), manager.clone());
+            PROCESSORS[cpu_id].init(cpu_id, Thread::new_init(), manager.clone());
         }
     }
 
@@ -25,7 +26,7 @@ pub fn init() {
     use core::str::FromStr;
     let cores = usize::from_str(env!("SMP")).unwrap();
     for i in 0..cores {
-        manager.add(Process::new_kernel(idle, i), 0);
+        manager.add(Thread::new_kernel(idle, i), 0);
     }
     crate::shell::run_user_shell();
 
@@ -34,12 +35,17 @@ pub fn init() {
 
 static PROCESSORS: [Processor; MAX_CPU_NUM] = [Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new()];
 
-/// Get current thread struct
+/// Get current process
+pub fn process() -> MutexGuard<'static, Process> {
+    current_thread().proc.lock()
+}
+
+/// Get current thread
 ///
 /// FIXME: It's obviously unsafe to get &mut !
-pub fn process() -> &'static mut Process {
+pub fn current_thread() -> &'static mut Thread {
     use core::mem::transmute;
-    let (process, _): (&mut Process, *const ()) = unsafe {
+    let (process, _): (&mut Thread, *const ()) = unsafe {
         transmute(processor().context())
     };
     process
@@ -55,5 +61,5 @@ pub fn processor() -> &'static Processor {
 
 #[no_mangle]
 pub fn new_kernel_context(entry: extern fn(usize) -> !, arg: usize) -> Box<Context> {
-    Process::new_kernel(entry, arg)
+    Thread::new_kernel(entry, arg)
 }

kernel/src/process/structs.rs

@@ -3,54 +3,64 @@ use alloc::{boxed::Box, collections::BTreeMap, string::String, sync::Arc, vec::V
 use log::*;
 use simple_filesystem::file::File;
 use spin::Mutex;
-use rcore_thread::Context;
 use xmas_elf::{ElfFile, header, program::{Flags, Type}};
 
-use crate::arch::interrupt::{Context as ArchContext, TrapFrame};
+use crate::arch::interrupt::{Context, TrapFrame};
 use crate::memory::{ByFrame, GlobalFrameAlloc, KernelStack, MemoryAttr, MemorySet};
 
 // TODO: avoid pub
+pub struct Thread {
+    pub context: Context,
+    pub kstack: KernelStack,
+    pub proc: Arc<Mutex<Process>>,
+}
+
 pub struct Process {
-    pub arch: ArchContext,
     pub memory_set: MemorySet,
-    pub kstack: KernelStack,
     pub files: BTreeMap<usize, Arc<Mutex<File>>>,
     pub cwd: String,
 }
 
-impl Context for Process {
-    unsafe fn switch_to(&mut self, target: &mut Context) {
+/// Let `rcore_thread` can switch between our `Thread`
+impl rcore_thread::Context for Thread {
+    unsafe fn switch_to(&mut self, target: &mut rcore_thread::Context) {
         use core::mem::transmute;
-        let (target, _): (&mut Process, *const ()) = transmute(target);
-        self.arch.switch(&mut target.arch);
+        let (target, _): (&mut Thread, *const ()) = transmute(target);
+        self.context.switch(&mut target.context);
     }
 }
 
-impl Process {
-    pub unsafe fn new_init() -> Box<Context> {
-        Box::new(Process {
-            arch: ArchContext::null(),
-            memory_set: MemorySet::new(),
+impl Thread {
+    /// Make a struct for the init thread
+    pub unsafe fn new_init() -> Box<Thread> {
+        Box::new(Thread {
+            context: Context::null(),
             kstack: KernelStack::new(),
+            proc: Arc::new(Mutex::new(Process {
+                memory_set: MemorySet::new(),
                 files: BTreeMap::default(),
                 cwd: String::new(),
+            })),
         })
     }
 
-    pub fn new_kernel(entry: extern fn(usize) -> !, arg: usize) -> Box<Context> {
+    /// Make a new kernel thread starting from `entry` with `arg`
+    pub fn new_kernel(entry: extern fn(usize) -> !, arg: usize) -> Box<Thread> {
         let memory_set = MemorySet::new();
         let kstack = KernelStack::new();
-        Box::new(Process {
-            arch: unsafe { ArchContext::new_kernel_thread(entry, arg, kstack.top(), memory_set.token()) },
-            memory_set,
+        Box::new(Thread {
+            context: unsafe { Context::new_kernel_thread(entry, arg, kstack.top(), memory_set.token()) },
             kstack,
+            proc: Arc::new(Mutex::new(Process {
+                memory_set,
                 files: BTreeMap::default(),
                 cwd: String::new(),
+            })),
         })
     }
 
-    /// Make a new user thread from ELF data
-    pub fn new_user<'a, Iter>(data: &[u8], args: Iter) -> Box<Process>
+    /// Make a new user process from ELF `data`
+    pub fn new_user<'a, Iter>(data: &[u8], args: Iter) -> Box<Thread>
         where Iter: Iterator<Item=&'a str>
     {
         // Parse elf
@@ -94,23 +104,25 @@ impl Process {
 
         let kstack = KernelStack::new();
 
-        Box::new(Process {
-            arch: unsafe {
-                ArchContext::new_user_thread(
+        Box::new(Thread {
+            context: unsafe {
+                Context::new_user_thread(
                     entry_addr, ustack_top, kstack.top(), is32, memory_set.token())
             },
-            memory_set,
             kstack,
+            proc: Arc::new(Mutex::new(Process {
+                memory_set,
                 files: BTreeMap::default(),
                 cwd: String::new(),
+            })),
         })
     }
 
-    /// Fork
-    pub fn fork(&self, tf: &TrapFrame) -> Box<Context> {
+    /// Fork a new process from current one
+    pub fn fork(&self, tf: &TrapFrame) -> Box<Thread> {
         info!("COME into fork!");
         // Clone memory set, make a new page table
-        let memory_set = self.memory_set.clone();
+        let memory_set = self.proc.lock().memory_set.clone();
         info!("finish mmset clone in fork!");
 
         // MMU:   copy data to the new space
@@ -126,12 +138,14 @@ impl Process {
         info!("temporary copy data!");
         let kstack = KernelStack::new();
 
-        Box::new(Process {
-            arch: unsafe { ArchContext::new_fork(tf, kstack.top(), memory_set.token()) },
-            memory_set,
+        Box::new(Thread {
+            context: unsafe { Context::new_fork(tf, kstack.top(), memory_set.token()) },
             kstack,
+            proc: Arc::new(Mutex::new(Process {
+                memory_set,
                 files: BTreeMap::default(),
                 cwd: String::new(),
+            })),
         })
     }
 }

kernel/src/shell.rs

@@ -10,9 +10,9 @@ pub fn run_user_shell() {
         println!("Going to user mode shell.");
         println!("Use 'ls' to list available programs.");
         let data = inode.read_as_vec().unwrap();
-        processor().manager().add(Process::new_user(data.as_slice(), "sh".split(' ')), 0);
+        processor().manager().add(Thread::new_user(data.as_slice(), "sh".split(' ')), 0);
     } else {
-        processor().manager().add(Process::new_kernel(shell, 0), 0);
+        processor().manager().add(Thread::new_kernel(shell, 0), 0);
     }
 }
 
@@ -29,7 +29,7 @@ pub extern fn shell(_arg: usize) -> ! {
         let name = cmd.split(' ').next().unwrap();
         if let Ok(file) = ROOT_INODE.lookup(name) {
             let data = file.read_as_vec().unwrap();
-            let pid = processor().manager().add(Process::new_user(data.as_slice(), cmd.split(' ')), thread::current().id());
+            let pid = processor().manager().add(Thread::new_user(data.as_slice(), cmd.split(' ')), thread::current().id());
             unsafe { thread::JoinHandle::<()>::_of(pid) }.join().unwrap();
         } else {
             println!("Program not exist");

kernel/src/syscall.rs

@@ -3,7 +3,7 @@
 use simple_filesystem::{INode, file::File, FileInfo, FileType, FsError};
 use core::{slice, str};
 use alloc::{sync::Arc, vec::Vec, string::String};
-use spin::Mutex;
+use spin::{Mutex, MutexGuard};
 use log::*;
 use bitflags::bitflags;
 use crate::arch::interrupt::TrapFrame;
@@ -61,7 +61,8 @@ fn sys_read(fd: usize, base: *mut u8, len: usize) -> SysResult {
     // TODO: check ptr
     info!("read: fd: {}, base: {:?}, len: {:#x}", fd, base, len);
     let slice = unsafe { slice::from_raw_parts_mut(base, len) };
-    let len = get_file(fd)?.lock().read(slice)?;
+    let proc = process();
+    let len = get_file(&proc, fd)?.lock().read(slice)?;
     Ok(len as isize)
 }
 
@@ -69,7 +70,8 @@ fn sys_write(fd: usize, base: *const u8, len: usize) -> SysResult {
     // TODO: check ptr
     info!("write: fd: {}, base: {:?}, len: {:#x}", fd, base, len);
     let slice = unsafe { slice::from_raw_parts(base, len) };
-    let len = get_file(fd)?.lock().write(slice)?;
+    let proc = process();
+    let len = get_file(&proc, fd)?.lock().write(slice)?;
     Ok(len as isize)
 }
 
@@ -103,7 +105,8 @@ fn sys_close(fd: usize) -> SysResult {
 fn sys_fstat(fd: usize, stat_ptr: *mut Stat) -> SysResult {
     // TODO: check ptr
     info!("fstat: {}", fd);
-    let file = get_file(fd)?;
+    let proc = process();
+    let file = get_file(&proc, fd)?;
     let stat = Stat::from(file.lock().info()?);
     unsafe { stat_ptr.write(stat); }
     Ok(0)
@@ -115,7 +118,8 @@ fn sys_fstat(fd: usize, stat_ptr: *mut Stat) -> SysResult {
 fn sys_getdirentry(fd: usize, dentry_ptr: *mut DirEntry) -> SysResult {
     // TODO: check ptr
     info!("getdirentry: {}", fd);
-    let file = get_file(fd)?;
+    let proc = process();
+    let file = get_file(&proc, fd)?;
     let dentry = unsafe { &mut *dentry_ptr };
     if !dentry.check() {
         return Err(SysError::Inval);
@@ -131,7 +135,8 @@ fn sys_getdirentry(fd: usize, dentry_ptr: *mut DirEntry) -> SysResult {
 
 fn sys_dup(fd1: usize, fd2: usize) -> SysResult {
     info!("dup: {} {}", fd1, fd2);
-    let file = get_file(fd1)?;
+    let proc = process();
+    let file = get_file(&proc, fd1)?;
     if process().files.contains_key(&fd2) {
         return Err(SysError::Inval);
     }
@@ -141,7 +146,7 @@ fn sys_dup(fd1: usize, fd2: usize) -> SysResult {
 
 /// Fork the current process. Return the child's PID.
 fn sys_fork(tf: &TrapFrame) -> SysResult {
-    let context = process().fork(tf);
+    let context = current_thread().fork(tf);
     let pid = processor().manager().add(context, thread::current().id());
     info!("fork: {} -> {}", thread::current().id(), pid);
     Ok(pid as isize)
@@ -207,19 +212,19 @@ fn sys_exec(name: *const u8, argc: usize, argv: *const *const u8, tf: &mut TrapF
     unsafe { buf.set_len(size); }
     inode.read_at(0, buf.as_mut_slice())?;
 
-    // Make new Context
+    // Make new Thread
     let iter = args.iter().map(|s| s.as_str());
-    let mut context = Process::new_user(buf.as_slice(), iter);
+    let mut thread = Thread::new_user(buf.as_slice(), iter);
 
     // Activate new page table
-    unsafe { context.memory_set.activate(); }
+    unsafe { thread.proc.lock().memory_set.activate(); }
 
     // Modify the TrapFrame
-    *tf = unsafe { context.arch.get_init_tf() };
+    *tf = unsafe { thread.context.get_init_tf() };
 
     // Swap Context but keep KStack
-    ::core::mem::swap(&mut process().kstack, &mut context.kstack);
-    ::core::mem::swap(process(), &mut *context);
+    ::core::mem::swap(&mut current_thread().kstack, &mut thread.kstack);
+    ::core::mem::swap(current_thread(), &mut *thread);
 
     Ok(0)
 }
@@ -278,8 +283,8 @@ fn sys_putc(c: char) -> SysResult {
     Ok(0)
 }
 
-fn get_file(fd: usize) -> Result<&'static Arc<Mutex<File>>, SysError> {
-    process().files.get(&fd).ok_or(SysError::Inval)
+fn get_file<'a>(proc: &'a MutexGuard<'static, Process>, fd: usize) -> Result<&'a Arc<Mutex<File>>, SysError> {
+    proc.files.get(&fd).ok_or(SysError::Inval)
 }
 
 pub type SysResult = Result<isize, SysError>;