Create a new MemoryAllocator (and initialize it)

src/memory/mod.rs

@@ -9,6 +9,7 @@
 
 pub use self::area_frame_allocator::AreaFrameAllocator;
 pub use self::paging::remap_the_kernel;
+pub use self::stack_allocator::Stack;
 use self::paging::PhysicalAddress;
 use multiboot2::BootInformation;
 
@@ -18,7 +19,7 @@ mod stack_allocator;
 
 pub const PAGE_SIZE: usize = 4096;
 
-pub fn init(boot_info: &BootInformation) {
+pub fn init(boot_info: &BootInformation) -> MemoryController {
     assert_has_not_been_called!("memory::init must be called only once");
 
     let memory_map_tag = boot_info.memory_map_tag().expect("Memory map tag required");
@@ -59,6 +60,34 @@ pub fn init(boot_info: &BootInformation) {
     for page in Page::range_inclusive(heap_start_page, heap_end_page) {
         active_table.map(page, paging::WRITABLE, &mut frame_allocator);
     }
+
+    let stack_allocator = {
+        let stack_alloc_start = heap_end_page + 1;
+        let stack_alloc_end = stack_alloc_start + 100;
+        let stack_alloc_range = Page::range_inclusive(stack_alloc_start, stack_alloc_end);
+        stack_allocator::StackAllocator::new(stack_alloc_range)
+    };
+
+    MemoryController {
+        active_table: active_table,
+        frame_allocator: frame_allocator,
+        stack_allocator: stack_allocator,
+    }
+}
+
+pub struct MemoryController {
+    active_table: paging::ActivePageTable,
+    frame_allocator: AreaFrameAllocator,
+    stack_allocator: stack_allocator::StackAllocator,
+}
+
+impl MemoryController {
+    pub fn alloc_stack(&mut self, size_in_pages: usize) -> Option<Stack> {
+        let &mut MemoryController { ref mut active_table,
+                                    ref mut frame_allocator,
+                                    ref mut stack_allocator } = self;
+        stack_allocator.alloc_stack(active_table, frame_allocator, size_in_pages)
+    }
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]

src/memory/paging/mod.rs

@@ -11,7 +11,7 @@ pub use self::entry::*;
 use memory::{PAGE_SIZE, Frame, FrameAllocator};
 use self::temporary_page::TemporaryPage;
 pub use self::mapper::Mapper;
-use core::ops::{Deref, DerefMut};
+use core::ops::{Add, Deref, DerefMut};
 use multiboot2::BootInformation;
 
 mod entry;
@@ -62,6 +62,14 @@ impl Page {
     }
 }
 
+impl Add<usize> for Page {
+    type Output = Page;
+
+    fn add(self, rhs: usize) -> Page {
+        Page { number: self.number + rhs }
+    }
+}
+
 #[derive(Clone)]
 pub struct PageIter {
     start: Page,