Revert "BitmapView: Disable mutations of the underlying Bitmap"

This reverts commit f252091.

AK/Bitmap.h

@@ -30,6 +30,12 @@ class Bitmap {
  fill(default_value);
  }
 
+ Bitmap(u8* data, size_t size)
+ : m_data(data)
+ , m_size(size)
+ {
+ }
+
  BitmapView view() { return { m_data, m_size }; }
  const BitmapView view() const { return { m_data, m_size }; }
 
@@ -102,86 +108,11 @@ class Bitmap {
  }
  }
 
- template<bool VALUE, bool verify_that_all_bits_flip = false>
- void set_range(size_t start, size_t len)
- {
- VERIFY(start < m_size);
- VERIFY(start + len <= m_size);
- if (len == 0)
- return;
-
- static const u8 bitmask_first_byte[8] = { 0xFF, 0xFE, 0xFC, 0xF8, 0xF0, 0xE0, 0xC0, 0x80 };
- static const u8 bitmask_last_byte[8] = { 0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F };
-
- u8* first = &m_data[start / 8];
- u8* last = &m_data[(start + len) / 8];
- u8 byte_mask = bitmask_first_byte[start % 8];
- if (first == last) {
- byte_mask &= bitmask_last_byte[(start + len) % 8];
- if constexpr (verify_that_all_bits_flip) {
- if constexpr (VALUE) {
- VERIFY((*first & byte_mask) == 0);
- } else {
- VERIFY((*first & byte_mask) == byte_mask);
- }
- }
- if constexpr (VALUE)
- *first |= byte_mask;
- else
- *first &= ~byte_mask;
- } else {
- if constexpr (verify_that_all_bits_flip) {
- if constexpr (VALUE) {
- VERIFY((*first & byte_mask) == 0);
- } else {
- VERIFY((*first & byte_mask) == byte_mask);
- }
- }
- if constexpr (VALUE)
- *first |= byte_mask;
- else
- *first &= ~byte_mask;
- byte_mask = bitmask_last_byte[(start + len) % 8];
- if constexpr (verify_that_all_bits_flip) {
- if constexpr (VALUE) {
- VERIFY((*last & byte_mask) == 0);
- } else {
- VERIFY((*last & byte_mask) == byte_mask);
- }
- }
- if constexpr (VALUE)
- *last |= byte_mask;
- else
- *last &= ~byte_mask;
- if (++first < last) {
- if constexpr (VALUE)
- __builtin_memset(first, 0xFF, last - first);
- else
- __builtin_memset(first, 0x0, last - first);
- }
- }
- }
-
- void set_range(size_t start, size_t len, bool value)
- {
- if (value)
- set_range<true, false>(start, len);
- else
- set_range<false, false>(start, len);
- }
-
- void set_range_and_verify_that_all_bits_flip(size_t start, size_t len, bool value)
- {
- if (value)
- set_range<true, true>(start, len);
- else
- set_range<false, true>(start, len);
- }
+ template<bool VALUE>
+ void set_range(size_t start, size_t len) { return view().set_range<VALUE, false>(start, len); }
+ void set_range(size_t start, size_t len, bool value) { return view().set_range(start, len, value); }
 
- void fill(bool value)
- {
- __builtin_memset(m_data, value ? 0xff : 0x00, size_in_bytes());
- }
+ void fill(bool value) { view().fill(value); }
 
  Optional<size_t> find_one_anywhere_set(size_t hint = 0) const { return view().find_one_anywhere<true>(hint); }
  Optional<size_t> find_one_anywhere_unset(size_t hint = 0) const { return view().find_one_anywhere<false>(hint); }

AK/BitmapView.h

@@ -6,10 +6,12 @@
 
 #pragma once
 
+#include <AK/Noncopyable.h>
 #include <AK/Optional.h>
 #include <AK/Platform.h>
 #include <AK/StdLibExtras.h>
 #include <AK/Types.h>
+#include <AK/kmalloc.h>
 
 namespace AK {
 
@@ -93,8 +95,90 @@ class BitmapView {
 
  bool is_null() const { return !m_data; }
 
+ u8* data() { return m_data; }
  const u8* data() const { return m_data; }
 
+ template<bool VALUE, bool verify_that_all_bits_flip>
+ void set_range(size_t start, size_t len)
+ {
+ VERIFY(start < m_size);
+ VERIFY(start + len <= m_size);
+ if (len == 0)
+ return;
+
+ static const u8 bitmask_first_byte[8] = { 0xFF, 0xFE, 0xFC, 0xF8, 0xF0, 0xE0, 0xC0, 0x80 };
+ static const u8 bitmask_last_byte[8] = { 0x0, 0x1, 0x3, 0x7, 0xF, 0x1F, 0x3F, 0x7F };
+
+ u8* first = &m_data[start / 8];
+ u8* last = &m_data[(start + len) / 8];
+ u8 byte_mask = bitmask_first_byte[start % 8];
+ if (first == last) {
+ byte_mask &= bitmask_last_byte[(start + len) % 8];
+ if constexpr (verify_that_all_bits_flip) {
+ if constexpr (VALUE) {
+ VERIFY((*first & byte_mask) == 0);
+ } else {
+ VERIFY((*first & byte_mask) == byte_mask);
+ }
+ }
+ if constexpr (VALUE)
+ *first |= byte_mask;
+ else
+ *first &= ~byte_mask;
+ } else {
+ if constexpr (verify_that_all_bits_flip) {
+ if constexpr (VALUE) {
+ VERIFY((*first & byte_mask) == 0);
+ } else {
+ VERIFY((*first & byte_mask) == byte_mask);
+ }
+ }
+ if constexpr (VALUE)
+ *first |= byte_mask;
+ else
+ *first &= ~byte_mask;
+ byte_mask = bitmask_last_byte[(start + len) % 8];
+ if constexpr (verify_that_all_bits_flip) {
+ if constexpr (VALUE) {
+ VERIFY((*last & byte_mask) == 0);
+ } else {
+ VERIFY((*last & byte_mask) == byte_mask);
+ }
+ }
+ if constexpr (VALUE)
+ *last |= byte_mask;
+ else
+ *last &= ~byte_mask;
+ if (++first < last) {
+ if constexpr (VALUE)
+ __builtin_memset(first, 0xFF, last - first);
+ else
+ __builtin_memset(first, 0x0, last - first);
+ }
+ }
+ }
+
+ void set_range(size_t start, size_t len, bool value)
+ {
+ if (value)
+ set_range<true, false>(start, len);
+ else
+ set_range<false, false>(start, len);
+ }
+
+ void set_range_and_verify_that_all_bits_flip(size_t start, size_t len, bool value)
+ {
+ if (value)
+ set_range<true, true>(start, len);
+ else
+ set_range<false, true>(start, len);
+ }
+
+ void fill(bool value)
+ {
+ __builtin_memset(m_data, value ? 0xff : 0x00, size_in_bytes());
+ }
+
  template<bool VALUE>
  Optional<size_t> find_one_anywhere(size_t hint = 0) const
  {

Kernel/Heap/Heap.h

@@ -6,7 +6,7 @@
 
 #pragma once
 
-#include <AK/Bitmap.h>
+#include <AK/BitmapView.h>
 #include <AK/ScopeGuard.h>
 #include <AK/TemporaryChange.h>
 #include <AK/Vector.h>
@@ -32,7 +32,7 @@ class Heap {
  Heap(u8* memory, size_t memory_size)
  : m_total_chunks(calculate_chunks(memory_size))
  , m_chunks(memory)
- , m_bitmap(m_total_chunks, false)
+ , m_bitmap(memory + m_total_chunks * CHUNK_SIZE, m_total_chunks)
  {
  // To keep the alignment of the memory passed in, place the bitmap
  // at the end of the memory block.
@@ -153,7 +153,7 @@ class Heap {
  size_t m_total_chunks { 0 };
  size_t m_allocated_chunks { 0 };
  u8* m_chunks { nullptr };
- Bitmap m_bitmap;
+ BitmapView m_bitmap;
 };
 
 template<typename ExpandHeap>