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Author SHA1 Message Date
Drew Galbraith a16dcc2aa9 [Zion] Use a binary tree to store address space mappings. 2023-11-03 19:47:39 -07:00
Drew Galbraith 98f029ae23 [Glacier] Add a binary tree implementation.
Additionally add an optional class to return found values
in the tree. And a reference container (Ref) similar to
std::reference_wrapper to allow storing references in containers.
2023-11-03 19:46:30 -07:00
6 changed files with 255 additions and 20 deletions

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@ -0,0 +1,173 @@
#pragma once
#include "glacier/container/optional.h"
#include "glacier/container/pair.h"
#include "glacier/memory/move.h"
#include "glacier/memory/ref_counted.h"
#include "glacier/memory/ref_ptr.h"
#include "glacier/memory/reference.h"
#include "glacier/memory/unique_ptr.h"
namespace glcr {
template <typename K, typename V>
class BinaryTree {
public:
BinaryTree() = default;
BinaryTree(const BinaryTree&) = delete;
// FIXME: Implement move.
BinaryTree(BinaryTree&&) = delete;
void Insert(K key, V&& value);
void Delete(K key);
Optional<Ref<V>> Predecessor(K key);
Optional<Ref<V>> Successor(K key);
Optional<Ref<V>> Find(K key);
private:
// TODO: Consider adding a sharedptr type to
// avoid making this "RefCounted".
struct BinaryNode : public RefCounted<BinaryNode> {
K key;
V value;
RefPtr<BinaryNode> left;
RefPtr<BinaryNode> right;
RefPtr<BinaryNode> parent;
BinaryNode(K k, V v) : key(k), value(Move(v)) {}
};
RefPtr<BinaryNode> root_;
// If this node exists, return it. Otherwise, this
// will be the parent of where this node would be inserted.
RefPtr<BinaryNode> FindOrInsertionParent(K key);
};
template <typename K, typename V>
void BinaryTree<K, V>::Insert(K key, V&& value) {
auto parent = FindOrInsertionParent(key);
if (parent.empty()) {
root_ = AdoptPtr(new BinaryNode(key, Move(value)));
return;
}
if (parent->key > key) {
parent->left = AdoptPtr(new BinaryNode(key, Move(value)));
parent->left->parent = parent;
} else if (parent->key < key) {
parent->right = AdoptPtr(new BinaryNode(key, Move(value)));
parent->right->parent = parent;
} else {
parent->value = Move(value);
}
}
template <typename K, typename V>
void BinaryTree<K, V>::Delete(K key) {
// TODO: Implement Delete.
return;
}
template <typename K, typename V>
Optional<Ref<V>> BinaryTree<K, V>::Predecessor(K key) {
auto current = FindOrInsertionParent(key);
// The case where the current is the insertion parent and
// the predecessor is unique. If the key was going to be
// inserted as the left child, it shares its predecessor with the parent.
if (current->key < key) {
return Optional<Ref<V>>(current->value);
}
// Case where the predecessor is below us in the tree.
if (current->left) {
current = current->left;
while (current->right) {
current = current->right;
}
return {current->value};
}
// Case where the predecessor is above us in the tree.
auto parent = current->parent;
while (parent && (parent->left == current)) {
current = parent;
parent = current->parent;
}
if (parent) {
return {parent->value};
}
return {};
}
template <typename K, typename V>
Optional<Ref<V>> BinaryTree<K, V>::Successor(K key) {
auto current = FindOrInsertionParent(key);
// The case where the current is the insertion parent and
// the predecessor is unique. If the key was going to be
// inserted as the left child, it shares its predecessor with the parent.
if (current->key > key) {
return Optional<Ref<V>>(current->value);
}
// Case where the predecessor is below us in the tree.
if (current->right) {
current = current->right;
while (current->left) {
current = current->left;
}
return {current->value};
}
// Case where the predecessor is above us in the tree.
auto parent = current->parent;
while (parent && (parent->right == current)) {
current = parent;
parent = current->parent;
}
if (parent) {
return {parent->value};
}
return {};
}
template <typename K, typename V>
Optional<Ref<V>> BinaryTree<K, V>::Find(K key) {
auto current = FindOrInsertionParent(key);
if (current->key == key) {
return Optional<Ref<V>>(current->value);
}
return {};
}
template <typename K, typename V>
RefPtr<typename BinaryTree<K, V>::BinaryNode>
BinaryTree<K, V>::FindOrInsertionParent(K key) {
if (root_.empty()) {
return nullptr;
}
auto current = root_;
while (true) {
if (key == current->key) {
return current;
} else if (key < current->key) {
if (!current->left) {
return current;
}
current = current->left;
} else {
if (!current->right) {
return current;
}
current = current->right;
}
}
}
} // namespace glcr

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@ -0,0 +1,41 @@
#pragma once
#include "glacier/memory/move.h"
namespace glcr {
template <typename T>
class Optional {
public:
Optional() : empty_(nullptr), has_value_(false) {}
Optional(const T& value) : value_(value), has_value_(true) {}
Optional(T&& value) : value_(Move(value)), has_value_(true) {}
Optional(const Optional&) = default;
Optional(Optional&&) = default;
~Optional() {
if (has_value_) {
value_.~T();
}
}
bool empty() const { return !has_value_; }
explicit operator bool() { return has_value_; }
const T& value() const { return value_; }
T&& release_value() {
has_value_ = false;
return Move(value_);
}
T* operator->() { return &value_; }
T& operator*() { return value_; }
private:
union {
T value_;
void* empty_;
};
bool has_value_;
};
} // namespace glcr

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@ -51,6 +51,8 @@ class RefPtr {
T* get() const { return ptr_; };
T& operator*() const { return *ptr_; }
T* operator->() const { return ptr_; }
bool empty() const { return ptr_ == nullptr; }
operator bool() const { return ptr_ != nullptr; }
bool operator==(decltype(nullptr)) const { return (ptr_ == nullptr); }

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@ -0,0 +1,18 @@
#pragma once
namespace glcr {
template <typename T>
class Ref {
public:
Ref(T& ref) : ref_(ref) {}
Ref(const Ref& other) = default;
Ref(Ref&& other) = default;
operator T&() const { return ref_; }
private:
T& ref_;
};
} // namespace glcr

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@ -39,13 +39,13 @@ uint64_t AddressSpace::GetNextMemMapAddr(uint64_t size) {
void AddressSpace::MapInMemoryObject(
uint64_t vaddr, const glcr::RefPtr<MemoryObject>& mem_obj) {
memory_mappings_.PushBack({.vaddr = vaddr, .mem_obj = mem_obj});
memory_mappings_.Insert(vaddr, {.vaddr = vaddr, .mem_obj = mem_obj});
}
uint64_t AddressSpace::MapInMemoryObject(
const glcr::RefPtr<MemoryObject>& mem_obj) {
uint64_t vaddr = GetNextMemMapAddr(mem_obj->size());
memory_mappings_.PushBack({.vaddr = vaddr, .mem_obj = mem_obj});
memory_mappings_.Insert(vaddr, {.vaddr = vaddr, .mem_obj = mem_obj});
return vaddr;
}
@ -62,12 +62,13 @@ bool AddressSpace::HandlePageFault(uint64_t vaddr) {
return true;
}
MemoryMapping* mapping = GetMemoryMappingForAddr(vaddr);
if (mapping == nullptr) {
auto mapping_or = GetMemoryMappingForAddr(vaddr);
if (!mapping_or) {
return false;
}
uint64_t offset = vaddr - mapping->vaddr;
uint64_t physical_addr = mapping->mem_obj->PhysicalPageAtOffset(offset);
MemoryMapping& mapping = mapping_or.value();
uint64_t offset = vaddr - mapping.vaddr;
uint64_t physical_addr = mapping.mem_obj->PhysicalPageAtOffset(offset);
if (physical_addr == 0) {
dbgln("WARN: Memory object returned invalid physical addr.");
return false;
@ -79,16 +80,15 @@ bool AddressSpace::HandlePageFault(uint64_t vaddr) {
return true;
}
AddressSpace::MemoryMapping* AddressSpace::GetMemoryMappingForAddr(
uint64_t vaddr) {
auto iter = memory_mappings_.begin();
while (iter != memory_mappings_.end()) {
if ((vaddr >= (*iter).vaddr) &&
(vaddr < ((*iter).vaddr + (*iter).mem_obj->size()))) {
return &(*iter);
glcr::Optional<glcr::Ref<AddressSpace::MemoryMapping>>
AddressSpace::GetMemoryMappingForAddr(uint64_t vaddr) {
auto mapping_or = memory_mappings_.Predecessor(vaddr + 1);
if (!mapping_or) {
return mapping_or;
}
++iter;
MemoryMapping& mapping = mapping_or.value();
if (mapping.vaddr + mapping.mem_obj->size() <= vaddr) {
return {};
}
return 0;
return mapping_or;
}

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@ -1,6 +1,6 @@
#pragma once
#include <glacier/container/linked_list.h>
#include <glacier/container/binary_tree.h>
#include <glacier/memory/ref_ptr.h>
#include <stdint.h>
@ -92,7 +92,8 @@ class AddressSpace : public KernelObject {
uint64_t vaddr;
glcr::RefPtr<MemoryObject> mem_obj;
};
glcr::LinkedList<MemoryMapping> memory_mappings_;
glcr::BinaryTree<uint64_t, MemoryMapping> memory_mappings_;
MemoryMapping* GetMemoryMappingForAddr(uint64_t vaddr);
glcr::Optional<glcr::Ref<MemoryMapping>> GetMemoryMappingForAddr(
uint64_t vaddr);
};