Replace `AreaFrameAllocator` by `BitAllocator`. Set opt-level=1 to avoid stack overflow.

Cargo.toml

@@ -12,6 +12,10 @@ test = []
 qemu_auto_exit = []
 link_user_program = []
 
+[profile.dev]
+# enable RVO to avoid stack overflow
+opt-level = 1
+
 [profile.release]
 debug = true
 
@@ -31,6 +35,7 @@ arrayvec = { version = "0.4.7", default-features = false }
 log = "0.4"
 lazy_static = { version = "1.0.0", features = ["spin_no_std"] }
 simple-filesystem = { git = "https://github.com/wangrunji0408/SimpleFileSystem-Rust" }
+bit-allocator = { path = "crate/bit-allocator" }
 
 [build-dependencies]
 cc = "1.0"

crate/bit-allocator/src/lib.rs

@@ -10,6 +10,7 @@ pub trait BitAlloc: Default {
     const CAP: usize;
     fn alloc(&mut self) -> Option<usize>;
     fn dealloc(&mut self, key: usize);
+    fn insert(&mut self, range: Range<usize>);
     fn remove(&mut self, range: Range<usize>);
     fn any(&self) -> bool;
     fn test(&self, key: usize) -> bool;
@@ -22,20 +23,12 @@ pub type BitAlloc1M = BitAllocCascade16<BitAlloc64K>;
 pub type BitAlloc16M = BitAllocCascade16<BitAlloc1M>;
 pub type BitAlloc256M = BitAllocCascade16<BitAlloc16M>;
 
+#[derive(Default)]
 pub struct BitAllocCascade16<T: BitAlloc> {
     bitset: u16,
     sub: [T; 16],
 }
 
-impl<T: BitAlloc> Default for BitAllocCascade16<T> {
-    fn default() -> Self {
-        Self {
-            bitset: 0xffff,
-            sub: <[T; 16]>::default(),
-        }
-    }
-}
-
 impl<T: BitAlloc> BitAlloc for BitAllocCascade16<T> {
     const CAP: usize = T::CAP * 16;
 
@@ -54,15 +47,11 @@ impl<T: BitAlloc> BitAlloc for BitAllocCascade16<T> {
         self.sub[i].dealloc(key % T::CAP);
         self.bitset.set_bit(i, true);
     }
-    fn remove(&mut self, range: Range<usize>) {
-        let Range { start, end } = range;
-        assert!(end <= Self::CAP);
-        for i in start / T::CAP..=(end - 1) / T::CAP {
-            let begin = if start / T::CAP == i { start % T::CAP } else { 0 };
-            let end = if end / T::CAP == i { end % T::CAP } else { T::CAP };
-            self.sub[i].remove(begin..end);
-            self.bitset.set_bit(i, self.sub[i].any());
+    fn insert(&mut self, range: Range<usize>) {
+        self.for_range(range, |sub: &mut T, range| sub.insert(range));
     }
+    fn remove(&mut self, range: Range<usize>) {
+        self.for_range(range, |sub: &mut T, range| sub.remove(range));
     }
     fn any(&self) -> bool {
         self.bitset != 0
@@ -72,14 +61,22 @@ impl<T: BitAlloc> BitAlloc for BitAllocCascade16<T> {
     }
 }
 
-pub struct BitAlloc16(u16);
-
-impl Default for BitAlloc16 {
-    fn default() -> Self {
-        BitAlloc16(0xffff)
+impl<T: BitAlloc> BitAllocCascade16<T> {
+    fn for_range(&mut self, range: Range<usize>, f: impl Fn(&mut T, Range<usize>)) {
+        let Range { start, end } = range;
+        assert!(end <= Self::CAP);
+        for i in start / T::CAP..=(end - 1) / T::CAP {
+            let begin = if start / T::CAP == i { start % T::CAP } else { 0 };
+            let end = if end / T::CAP == i { end % T::CAP } else { T::CAP };
+            f(&mut self.sub[i], begin..end);
+            self.bitset.set_bit(i, self.sub[i].any());
+        }
     }
 }
 
+#[derive(Default)]
+pub struct BitAlloc16(u16);
+
 impl BitAlloc for BitAlloc16 {
     const CAP: usize = 16;
 
@@ -96,6 +93,9 @@ impl BitAlloc for BitAlloc16 {
         assert!(!self.test(key));
         self.0.set_bit(key, true);
     }
+    fn insert(&mut self, range: Range<usize>) {
+        self.0.set_bits(range.clone(), 0xffff.get_bits(range));
+    }
     fn remove(&mut self, range: Range<usize>) {
         self.0.set_bits(range, 0);
     }
@@ -141,6 +141,7 @@ mod tests {
     fn bitalloc16() {
         let mut ba = BitAlloc16::default();
         assert_eq!(BitAlloc16::CAP, 16);
+        ba.insert(0..16);
         for i in 0..16 {
             assert_eq!(ba.test(i), true);
         }
@@ -163,6 +164,7 @@ mod tests {
     fn bitalloc4k() {
         let mut ba = BitAlloc4K::default();
         assert_eq!(BitAlloc4K::CAP, 4096);
+        ba.insert(0..4096);
         for i in 0..4096 {
             assert_eq!(ba.test(i), true);
         }

src/lib.rs

@@ -37,6 +37,7 @@ extern crate arrayvec;
 #[macro_use]
 extern crate log;
 extern crate simple_filesystem;
+extern crate bit_allocator;
 
 #[macro_use]    // print!
 mod io;
@@ -107,13 +108,7 @@ pub extern "C" fn rust_main(multiboot_information_address: usize) -> ! {
 //        });
 //    }
 
-    loop{
-        println!("init ...");
-        let mut i = 0;
-        while i < 1 << 22 {
-            i += 1;
-        }
-    }
+    loop {}
 
     test_end!();
     unreachable!();

src/memory/area_frame_allocator.rs

@@ -1,122 +0,0 @@
-use memory::{Frame, FrameAllocator, PhysAddr};
-use multiboot2::{MemoryAreaIter, MemoryArea};
-use arrayvec::ArrayVec;
-
-pub struct AreaFrameAllocator {
-    next_free_frame: Frame,
-    current_area: Option<Area>,
-    areas: ArrayVec<[Area; 4]>,
-    kernel_start: Frame,
-    kernel_end: Frame,
-    multiboot_start: Frame,
-    multiboot_end: Frame,
-}
-
-// 必须写这句，否则不能放在Mutex中？？？
-unsafe impl Send for AreaFrameAllocator {}
-
-impl FrameAllocator for AreaFrameAllocator {
-    fn allocate_frame(&mut self) -> Option<Frame> {
-        if let Some(area) = self.current_area {
-            // "Clone" the frame to return it if it's free. Frame doesn't
-            // implement Clone, but we can construct an identical frame.
-            let frame = Frame{ number: self.next_free_frame.number };
-
-            // the last frame of the current area
-            let current_area_last_frame = {
-                let address = area.end_address() - 1;
-                Frame::of_addr(address as usize)
-            };
-
-            if frame > current_area_last_frame {
-                // all frames of current area are used, switch to next area
-                self.choose_next_area();
-            } else if frame >= self.kernel_start && frame <= self.kernel_end {
-                // `frame` is used by the kernel
-                self.next_free_frame = Frame {
-                    number: self.kernel_end.number + 1
-                };
-            } else if frame >= self.multiboot_start && frame <= self.multiboot_end {
-                // `frame` is used by the multiboot information structure
-                self.next_free_frame = Frame {
-                    number: self.multiboot_end.number + 1
-                };
-            } else {
-                // frame is unused, increment `next_free_frame` and return it
-                self.next_free_frame.number += 1;
-                return Some(frame);
-            }
-            // `frame` was not valid, try it again with the updated `next_free_frame`
-            self.allocate_frame()
-        } else {
-            None // no free frames left
-        }
-    }
-
-    fn deallocate_frame(&mut self, _frame: Frame) {
-        unimplemented!()
-    }
-}
-
-impl AreaFrameAllocator {
-    pub fn new(kernel_start: PhysAddr, kernel_end: PhysAddr,
-               multiboot_start: PhysAddr, multiboot_end: PhysAddr,
-               memory_areas: MemoryAreaIter) -> AreaFrameAllocator
-    {
-        let areas: ArrayVec<[Area; 4]> = memory_areas.map(|a| Area::from(a)).collect();
-
-        let mut allocator = AreaFrameAllocator {
-            next_free_frame: Frame::of_addr(0),
-            current_area: None,
-            areas,
-            kernel_start: Frame::of_addr(kernel_start.0 as usize),
-            kernel_end: Frame::of_addr(kernel_end.0 as usize),
-            multiboot_start: Frame::of_addr(multiboot_start.0 as usize),
-            multiboot_end: Frame::of_addr(multiboot_end.0 as usize),
-        };
-        allocator.choose_next_area();
-        allocator
-    }
-
-    fn choose_next_area(&mut self) {
-        self.current_area = self.areas.iter().filter(|area| {
-            let address = area.end_address() - 1;
-            Frame::of_addr(address as usize) >= self.next_free_frame
-        }).min_by_key(|area| area.start_address())
-            .map(|area| area.clone());
-
-        if let Some(area) = self.current_area {
-            let start_frame = Frame::of_addr(area.start_address());
-            if self.next_free_frame < start_frame {
-                self.next_free_frame = start_frame;
-            }
-        }
-    }
-}
-
-#[derive(Debug, Copy, Clone)]
-pub struct Area {
-    start: usize,
-    end: usize,
-}
-
-impl Area {
-    pub fn start_address(&self) -> usize {
-        self.start
-    }
-    pub fn end_address(&self) -> usize {
-        self.end
-    }
-    pub fn size(&self) -> usize {
-        self.end - self.start
-    }
-}
-
-impl<'a> From<&'a MemoryArea> for Area {
-    fn from(a: &'a MemoryArea) -> Self {
-        Area {
-            start: a.start_address(),
-            end: a.end_address(),
-        }
-    }
-}

src/memory/mod.rs

@@ -1,4 +1,3 @@
-pub use self::area_frame_allocator::AreaFrameAllocator;
 pub use arch::paging::*;
 pub use self::stack_allocator::*;
 pub use self::address::*;
@@ -12,18 +11,18 @@ use spin::{Mutex, MutexGuard};
 use super::HEAP_ALLOCATOR;
 
 mod memory_set;
-mod area_frame_allocator;
 pub mod heap_allocator;
 mod stack_allocator;
 mod address;
 mod frame;
 
-pub static FRAME_ALLOCATOR: Mutex<Option<AreaFrameAllocator>> = Mutex::new(None);
-pub static STACK_ALLOCATOR: Mutex<Option<StackAllocator>> = Mutex::new(None);
+lazy_static! {
+    static ref FRAME_ALLOCATOR: Mutex<BitAlloc64K> = Mutex::new(BitAlloc64K::default());
+}
+static STACK_ALLOCATOR: Mutex<Option<StackAllocator>> = Mutex::new(None);
 
 pub fn alloc_frame() -> Frame {
     FRAME_ALLOCATOR.lock()
-        .as_mut().expect("frame allocator is not initialized")
         .allocate_frame().expect("no more frame")
 }
 
@@ -69,25 +68,49 @@ pub fn init(boot_info: BootInformation) -> MemorySet {
     kernel_memory
 }
 
+use bit_allocator::{BitAlloc64K, BitAlloc};
+
+impl FrameAllocator for BitAlloc64K {
+    fn allocate_frame(&mut self) -> Option<Frame> {
+        self.alloc().map(|x| Frame { number: x })
+    }
+    fn deallocate_frame(&mut self, frame: Frame) {
+        self.dealloc(frame.number);
+    }
+}
+
 fn init_frame_allocator(boot_info: &BootInformation) {
-    let memory_map_tag = boot_info.memory_map_tag().expect(
-        "Memory map tag required");
-    let elf_sections_tag = boot_info.elf_sections_tag().expect(
-        "Elf sections tag required");
-
-    let kernel_start = PhysAddr(elf_sections_tag.sections()
-        .filter(|s| s.is_allocated()).map(|s| s.start_address()).min().unwrap());
-    let kernel_end = PhysAddr::from_kernel_virtual(elf_sections_tag.sections()
-        .filter(|s| s.is_allocated()).map(|s| s.end_address()).max().unwrap() as usize);
-
-    let boot_info_start = PhysAddr(boot_info.start_address() as u64);
-    let boot_info_end = PhysAddr(boot_info.end_address() as u64);
-
-    *FRAME_ALLOCATOR.lock() = Some(AreaFrameAllocator::new(
-        kernel_start, kernel_end,
-        boot_info_start, boot_info_end,
-        memory_map_tag.memory_areas(),
-    ));
+    let memory_areas = boot_info.memory_map_tag().expect("Memory map tag required")
+        .memory_areas();
+    let elf_sections = boot_info.elf_sections_tag().expect("Elf sections tag required")
+        .sections().filter(|s| s.is_allocated());
+
+    let mut ba = FRAME_ALLOCATOR.lock();
+    for area in memory_areas {
+        ba.insert(to_range(area.start_address(), area.end_address()));
+    }
+    for section in elf_sections {
+        ba.remove(to_range(section.start_address() as usize, section.end_address() as usize));
+    }
+    ba.remove(to_range(boot_info.start_address(), boot_info.end_address()));
+
+    use core::ops::Range;
+    fn to_range(mut start_addr: usize, mut end_addr: usize) -> Range<usize> {
+        use consts::KERNEL_OFFSET;
+        if start_addr >= KERNEL_OFFSET {
+            start_addr -= KERNEL_OFFSET;
+        }
+        if end_addr >= KERNEL_OFFSET {
+            end_addr -= KERNEL_OFFSET;
+        }
+        let page_start = start_addr / PAGE_SIZE;
+        let mut page_end = (end_addr - 1) / PAGE_SIZE + 1;
+        if page_end >= BitAlloc64K::CAP {
+            warn!("page num {:#x} out of range {:#x}", page_end, BitAlloc64K::CAP);
+            page_end = BitAlloc64K::CAP;
+        }
+        page_start..page_end
+    }
 }
 
 fn remap_the_kernel(boot_info: BootInformation) -> MemorySet {
@@ -96,7 +119,6 @@ fn remap_the_kernel(boot_info: BootInformation) -> MemorySet {
     use consts::{KERNEL_OFFSET, KERNEL_HEAP_OFFSET, KERNEL_HEAP_SIZE};
     memory_set.push(MemoryArea::new_kernel(KERNEL_OFFSET + 0xb8000, KERNEL_OFFSET + 0xb9000, MemoryAttr::default(), "VGA"));
     memory_set.push(MemoryArea::new(KERNEL_HEAP_OFFSET, KERNEL_HEAP_OFFSET + KERNEL_HEAP_SIZE, MemoryAttr::default(), "kernel_heap"));
-
     debug!("{:#x?}", memory_set);
 
     memory_set.switch();

src/process/mod.rs

@@ -27,13 +27,7 @@ pub fn init(mut ms: MemorySet) {
 pub static PROCESSOR: Once<SpinNoIrqLock<Processor>> = Once::new();
 
 extern fn idle_thread(arg: usize) -> ! {
-    loop {
-        println!("idle ...");
-        let mut i = 0;
-        while i < 1 << 22 {
-            i += 1;
-        }
-    }
+    loop {}
 }
 
 pub fn add_user_process(name: impl AsRef<str>, data: &[u8]) {