From 6da814be6a35ea9d3d6fcaeb302848ee557ebb3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Leonard=20K=C3=B6nig?= <leonard.koenig@fu-berlin.de>
Date: Tue, 30 Jun 2020 13:28:09 +0200
Subject: [PATCH] apply debug allocations
---
src/allocator.rs | 73 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 69 insertions(+), 4 deletions(-)
diff --git a/src/allocator.rs b/src/allocator.rs
index 05e9669..bd8ebbe 100644
--- a/src/allocator.rs
+++ b/src/allocator.rs
@@ -4,24 +4,89 @@ use core::ptr;
use core::ptr::NonNull;
use linked_list_allocator::Heap;
+#[cfg(feature = "debug_allocations")]
+use core::fmt::Write;
+#[cfg(feature = "debug_allocations")]
+use core::sync::atomic;
+#[cfg(feature = "debug_allocations")]
+use core::sync::atomic::AtomicUsize;
+
+
pub static mut HEAP: Heap = Heap::empty();
-struct TockAllocator;
+// With the "debug_allocations" feature, we use `AtomicUsize` to store the
+// statistics because:
+// - it is `Sync`, so we can use it in a static object (the allocator),
+// - it implements interior mutability, so we can use it in the allocator
+// methods (that take an immutable `&self` reference).
+struct TockAllocator {
+ #[cfg(feature = "debug_allocations")]
+ count: AtomicUsize,
+ #[cfg(feature = "debug_allocations")]
+ size: AtomicUsize,
+}
+
+impl TockAllocator {
+ const fn new() -> TockAllocator {
+ TockAllocator {
+ #[cfg(feature = "debug_allocations")]
+ count: AtomicUsize::new(0),
+ #[cfg(feature = "debug_allocations")]
+ size: AtomicUsize::new(0),
+ }
+ }
+}
+
unsafe impl GlobalAlloc for TockAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
- HEAP.allocate_first_fit(layout)
+ let ptr = HEAP
+ .allocate_first_fit(layout)
.ok()
- .map_or(ptr::null_mut(), NonNull::as_ptr)
+ .map_or(ptr::null_mut(), NonNull::as_ptr);
+
+ #[cfg(feature = "debug_allocations")]
+ {
+ self.count.fetch_add(1, atomic::Ordering::SeqCst);
+ self.size.fetch_add(layout.size(), atomic::Ordering::SeqCst);
+ writeln!(
+ crate::console::Console::new(),
+ "alloc[{}, {}] = {:?} ({} ptrs, {} bytes)",
+ layout.size(),
+ layout.align(),
+ ptr,
+ self.count.load(atomic::Ordering::SeqCst),
+ self.size.load(atomic::Ordering::SeqCst)
+ )
+ .unwrap();
+ }
+ ptr
}
+
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+ #[cfg(feature = "debug_allocations")]
+ {
+ self.count.fetch_sub(1, atomic::Ordering::SeqCst);
+ self.size.fetch_sub(layout.size(), atomic::Ordering::SeqCst);
+ writeln!(
+ crate::console::Console::new(),
+ "dealloc[{}, {}] = {:?} ({} ptrs, {} bytes)",
+ layout.size(),
+ layout.align(),
+ ptr,
+ self.count.load(atomic::Ordering::SeqCst),
+ self.size.load(atomic::Ordering::SeqCst)
+ )
+ .unwrap();
+ }
+
HEAP.deallocate(NonNull::new_unchecked(ptr), layout)
}
}
#[global_allocator]
-static ALLOCATOR: TockAllocator = TockAllocator;
+static ALLOCATOR: TockAllocator = TockAllocator::new();
#[cfg(not(feature = "custom_alloc_error_handler"))]
#[alloc_error_handler]
--
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