[heap_tracker] Use ankerl map instead of rb tree (#249)

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/249
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

3 files changed, 87 insertions, 206 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index e9aed1d7af..cbe1d35fc5 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -262,13 +262,13 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 endif()
 
 if (BOOST_NO_HEADERS)
-    target_link_libraries(common PUBLIC Boost::algorithm Boost::icl Boost::pool)
+  target_link_libraries(common PUBLIC Boost::algorithm Boost::icl Boost::pool)
 else()
-    target_link_libraries(common PUBLIC Boost::headers)
+  target_link_libraries(common PUBLIC Boost::headers)
 endif()
 
 if (lz4_ADDED)
-    target_include_directories(common PRIVATE ${lz4_SOURCE_DIR}/lib)
+  target_include_directories(common PRIVATE ${lz4_SOURCE_DIR}/lib)
 endif()
 
 target_link_libraries(common PUBLIC fmt::fmt stb::headers Threads::Threads)
@@ -280,6 +280,11 @@ else()
   target_link_libraries(common PRIVATE zstd)
 endif()
 
+if (TARGET unordered_dense::unordered_dense)
+  # weird quirk of system installs
+  target_link_libraries(common PUBLIC unordered_dense::unordered_dense)
+endif()
+
 if(ANDROID)
   # For ASharedMemory_create
   target_link_libraries(common PRIVATE android)
diff --git a/src/common/heap_tracker.cpp b/src/common/heap_tracker.cpp
index 6832087959..d509f2644c 100644
--- a/src/common/heap_tracker.cpp
+++ b/src/common/heap_tracker.cpp
@@ -1,3 +1,5 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -34,68 +36,60 @@ HeapTracker::~HeapTracker() = default;
 
 void HeapTracker::Map(size_t virtual_offset, size_t host_offset, size_t length,
                       MemoryPermission perm, bool is_separate_heap) {
+    bool rebuild_required = false;
     // When mapping other memory, map pages immediately.
     if (!is_separate_heap) {
         m_buffer.Map(virtual_offset, host_offset, length, perm, false);
         return;
     }
-
     {
-        // We are mapping part of a separate heap.
+        // We are mapping part of a separate heap and insert into mappings.
         std::scoped_lock lk{m_lock};
-
-        auto* const map = new SeparateHeapMap{
-            .vaddr = virtual_offset,
+        m_map_count++;
+        const auto it = m_mappings.insert_or_assign(virtual_offset, SeparateHeapMap{
             .paddr = host_offset,
             .size = length,
             .tick = m_tick++,
             .perm = perm,
             .is_resident = false,
-        };
-
-        // Insert into mappings.
-        m_map_count++;
-        m_mappings.insert(*map);
+        });
+        // Update tick before possible rebuild.
+        it.first->second.tick = m_tick++;
+        // Check if we need to rebuild.
+        if (m_resident_map_count >= m_max_resident_map_count)
+            rebuild_required = true;
+        // Map the area.
+        m_buffer.Map(it.first->first, it.first->second.paddr, it.first->second.size, it.first->second.perm, false);
+        // This map is now resident.
+        it.first->second.is_resident = true;
+        m_resident_map_count++;
+        m_resident_mappings.insert(*it.first);
     }
-
-    // Finally, map.
-    this->DeferredMapSeparateHeap(virtual_offset);
+    // A rebuild was required, so perform it now.
+    if (rebuild_required)
+        this->RebuildSeparateHeapAddressSpace();
 }
 
 void HeapTracker::Unmap(size_t virtual_offset, size_t size, bool is_separate_heap) {
     // If this is a separate heap...
     if (is_separate_heap) {
         std::scoped_lock lk{m_lock};
-
-        const SeparateHeapMap key{
-            .vaddr = virtual_offset,
-        };
-
         // Split at the boundaries of the region we are removing.
         this->SplitHeapMapLocked(virtual_offset);
         this->SplitHeapMapLocked(virtual_offset + size);
-
         // Erase all mappings in range.
-        auto it = m_mappings.find(key);
-        while (it != m_mappings.end() && it->vaddr < virtual_offset + size) {
-            // Get underlying item.
-            auto* const item = std::addressof(*it);
-
+        auto it = m_mappings.find(virtual_offset);
+        while (it != m_mappings.end() && it->first < virtual_offset + size) {
             // If resident, erase from resident map.
-            if (item->is_resident) {
+            if (it->second.is_resident) {
                 ASSERT(--m_resident_map_count >= 0);
-                m_resident_mappings.erase(m_resident_mappings.iterator_to(*item));
+                m_resident_mappings.erase(m_resident_mappings.find(it->first));
             }
-
             // Erase from map.
             ASSERT(--m_map_count >= 0);
             it = m_mappings.erase(it);
-
-            // Free the item.
-            delete item;
         }
     }
-
     // Unmap pages.
     m_buffer.Unmap(virtual_offset, size, false);
 }
@@ -117,110 +111,51 @@ void HeapTracker::Protect(size_t virtual_offset, size_t size, MemoryPermission p
 
         {
             std::scoped_lock lk2{m_lock};
-
-            const SeparateHeapMap key{
-                .vaddr = next,
-            };
-
             // Try to get the next mapping corresponding to this address.
-            const auto it = m_mappings.nfind(key);
-
+            const auto it = m_mappings.find(next);
             if (it == m_mappings.end()) {
                 // There are no separate heap mappings remaining.
                 next = end;
                 should_protect = true;
-            } else if (it->vaddr == cur) {
+            } else if (it->first == cur) {
                 // We are in range.
                 // Update permission bits.
-                it->perm = perm;
+                it->second.perm = perm;
 
                 // Determine next address and whether we should protect.
-                next = cur + it->size;
-                should_protect = it->is_resident;
+                next = cur + it->second.size;
+                should_protect = it->second.is_resident;
             } else /* if (it->vaddr > cur) */ {
                 // We weren't in range, but there is a block coming up that will be.
-                next = it->vaddr;
+                next = it->first;
                 should_protect = true;
             }
         }
 
         // Clamp to end.
         next = std::min(next, end);
-
         // Reprotect, if we need to.
-        if (should_protect) {
+        if (should_protect)
             m_buffer.Protect(cur, next - cur, perm);
-        }
-
         // Advance.
         cur = next;
     }
 }
 
-bool HeapTracker::DeferredMapSeparateHeap(u8* fault_address) {
-    if (m_buffer.IsInVirtualRange(fault_address)) {
-        return this->DeferredMapSeparateHeap(fault_address - m_buffer.VirtualBasePointer());
-    }
-
-    return false;
-}
-
-bool HeapTracker::DeferredMapSeparateHeap(size_t virtual_offset) {
-    bool rebuild_required = false;
-
-    {
-        std::scoped_lock lk{m_lock};
-
-        // Check to ensure this was a non-resident separate heap mapping.
-        const auto it = this->GetNearestHeapMapLocked(virtual_offset);
-        if (it == m_mappings.end() || it->is_resident) {
-            return false;
-        }
-
-        // Update tick before possible rebuild.
-        it->tick = m_tick++;
-
-        // Check if we need to rebuild.
-        if (m_resident_map_count > m_max_resident_map_count) {
-            rebuild_required = true;
-        }
-
-        // Map the area.
-        m_buffer.Map(it->vaddr, it->paddr, it->size, it->perm, false);
-
-        // This map is now resident.
-        it->is_resident = true;
-        m_resident_map_count++;
-        m_resident_mappings.insert(*it);
-    }
-
-    if (rebuild_required) {
-        // A rebuild was required, so perform it now.
-        this->RebuildSeparateHeapAddressSpace();
-    }
-
-    return true;
-}
-
 void HeapTracker::RebuildSeparateHeapAddressSpace() {
     std::scoped_lock lk{m_rebuild_lock, m_lock};
-
     ASSERT(!m_resident_mappings.empty());
-
     // Dump half of the mappings.
-    //
     // Despite being worse in theory, this has proven to be better in practice than more
     // regularly dumping a smaller amount, because it significantly reduces average case
     // lock contention.
-    const size_t desired_count = std::min(m_resident_map_count, m_max_resident_map_count) / 2;
-    const size_t evict_count = m_resident_map_count - desired_count;
+    std::size_t const desired_count = std::min(m_resident_map_count, m_max_resident_map_count) / 2;
+    std::size_t const evict_count = m_resident_map_count - desired_count;
     auto it = m_resident_mappings.begin();
-
-    for (size_t i = 0; i < evict_count && it != m_resident_mappings.end(); i++) {
+    for (std::size_t i = 0; i < evict_count && it != m_resident_mappings.end(); i++) {
         // Unmark and unmap.
-        it->is_resident = false;
-        m_buffer.Unmap(it->vaddr, it->size, false);
-
+        it->second.is_resident = false;
+        m_buffer.Unmap(it->first, it->second.size, false);
         // Advance.
         ASSERT(--m_resident_map_count >= 0);
         it = m_resident_mappings.erase(it);
@@ -229,53 +164,32 @@ void HeapTracker::RebuildSeparateHeapAddressSpace() {
 
 void HeapTracker::SplitHeapMap(VAddr offset, size_t size) {
     std::scoped_lock lk{m_lock};
-
     this->SplitHeapMapLocked(offset);
     this->SplitHeapMapLocked(offset + size);
 }
 
 void HeapTracker::SplitHeapMapLocked(VAddr offset) {
-    const auto it = this->GetNearestHeapMapLocked(offset);
-    if (it == m_mappings.end() || it->vaddr == offset) {
-        // Not contained or no split required.
-        return;
-    }
-
-    // Cache the original values.
-    auto* const left = std::addressof(*it);
-    const size_t orig_size = left->size;
-
-    // Adjust the left map.
-    const size_t left_size = offset - left->vaddr;
-    left->size = left_size;
-
-    // Create the new right map.
-    auto* const right = new SeparateHeapMap{
-        .vaddr = left->vaddr + left_size,
-        .paddr = left->paddr + left_size,
-        .size = orig_size - left_size,
-        .tick = left->tick,
-        .perm = left->perm,
-        .is_resident = left->is_resident,
-    };
-
-    // Insert the new right map.
-    m_map_count++;
-    m_mappings.insert(*right);
-
-    // If resident, also insert into resident map.
-    if (right->is_resident) {
-        m_resident_map_count++;
-        m_resident_mappings.insert(*right);
+    auto it = this->GetNearestHeapMapLocked(offset);
+    if (it != m_mappings.end() && it->first != offset) {
+        // Adjust left iterator
+        auto const orig_size = it->second.size;
+        auto const left_size = offset - it->first;
+        it->second.size = left_size;
+        // Insert the new right map.
+        auto const right = SeparateHeapMap{
+            .paddr = it->second.paddr + left_size,
+            .size = orig_size - left_size,
+            .tick = it->second.tick,
+            .perm = it->second.perm,
+            .is_resident = it->second.is_resident,
+        };
+        m_map_count++;
+        auto rit = m_mappings.insert_or_assign(it->first + left_size, right);
+        if (rit.first->second.is_resident) {
+            m_resident_map_count++;
+            m_resident_mappings.insert(*rit.first);
+        }
     }
 }
 
-HeapTracker::AddrTree::iterator HeapTracker::GetNearestHeapMapLocked(VAddr offset) {
-    const SeparateHeapMap key{
-        .vaddr = offset,
-    };
-
-    return m_mappings.find(key);
-}
-
 } // namespace Common
diff --git a/src/common/heap_tracker.h b/src/common/heap_tracker.h
index ee5b0bf43a..14b5401c18 100644
--- a/src/common/heap_tracker.h
+++ b/src/common/heap_tracker.h
@@ -1,93 +1,55 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
-#include <atomic>
 #include <mutex>
-#include <set>
 #include <shared_mutex>
-
+#include <ankerl/unordered_dense.h>
 #include "common/host_memory.h"
-#include "common/intrusive_red_black_tree.h"
 
 namespace Common {
 
 struct SeparateHeapMap {
-    Common::IntrusiveRedBlackTreeNode addr_node{};
-    Common::IntrusiveRedBlackTreeNode tick_node{};
-    VAddr vaddr{};
-    PAddr paddr{};
-    size_t size{};
-    size_t tick{};
-    MemoryPermission perm{};
-    bool is_resident{};
-};
-
-struct SeparateHeapMapAddrComparator {
-    static constexpr int Compare(const SeparateHeapMap& lhs, const SeparateHeapMap& rhs) {
-        if (lhs.vaddr < rhs.vaddr) {
-            return -1;
-        } else if (lhs.vaddr <= (rhs.vaddr + rhs.size - 1)) {
-            return 0;
-        } else {
-            return 1;
-        }
-    }
-};
-
-struct SeparateHeapMapTickComparator {
-    static constexpr int Compare(const SeparateHeapMap& lhs, const SeparateHeapMap& rhs) {
-        if (lhs.tick < rhs.tick) {
-            return -1;
-        } else if (lhs.tick > rhs.tick) {
-            return 1;
-        } else {
-            return SeparateHeapMapAddrComparator::Compare(lhs, rhs);
-        }
-    }
+    PAddr paddr{}; //8
+    std::size_t size{}; //8 (16)
+    std::size_t tick{}; //8 (24)
+    // 4 bits needed, sync with host_memory.h if needed
+    MemoryPermission perm : 4 = MemoryPermission::Read;
+    bool is_resident : 1 = false;
 };
+static_assert(sizeof(SeparateHeapMap) == 32); //half a cache line! good for coherency
 
 class HeapTracker {
 public:
     explicit HeapTracker(Common::HostMemory& buffer);
     ~HeapTracker();
-
-    void Map(size_t virtual_offset, size_t host_offset, size_t length, MemoryPermission perm,
-             bool is_separate_heap);
+    void Map(size_t virtual_offset, size_t host_offset, size_t length, MemoryPermission perm, bool is_separate_heap);
     void Unmap(size_t virtual_offset, size_t size, bool is_separate_heap);
     void Protect(size_t virtual_offset, size_t length, MemoryPermission perm);
-    u8* VirtualBasePointer() {
+    inline u8* VirtualBasePointer() noexcept {
         return m_buffer.VirtualBasePointer();
     }
-
-    bool DeferredMapSeparateHeap(u8* fault_address);
-    bool DeferredMapSeparateHeap(size_t virtual_offset);
-
 private:
-    using AddrTreeTraits =
-        Common::IntrusiveRedBlackTreeMemberTraitsDeferredAssert<&SeparateHeapMap::addr_node>;
-    using AddrTree = AddrTreeTraits::TreeType<SeparateHeapMapAddrComparator>;
-
-    using TickTreeTraits =
-        Common::IntrusiveRedBlackTreeMemberTraitsDeferredAssert<&SeparateHeapMap::tick_node>;
-    using TickTree = TickTreeTraits::TreeType<SeparateHeapMapTickComparator>;
-
-    AddrTree m_mappings{};
-    TickTree m_resident_mappings{};
-
+    // TODO: You may want to "fake-map" the first 2GB of 64-bit address space
+    // and dedicate it entirely to a recursive PTE mapping :)
+    // However Ankerl is way better than using an RB tree, in all senses
+    using AddrTree = ankerl::unordered_dense::map<VAddr, SeparateHeapMap>;
+    AddrTree m_mappings;
+    using TicksTree = ankerl::unordered_dense::map<VAddr, SeparateHeapMap>;
+    TicksTree m_resident_mappings;
 private:
     void SplitHeapMap(VAddr offset, size_t size);
     void SplitHeapMapLocked(VAddr offset);
-
-    AddrTree::iterator GetNearestHeapMapLocked(VAddr offset);
-
     void RebuildSeparateHeapAddressSpace();
-
+    inline HeapTracker::AddrTree::iterator GetNearestHeapMapLocked(VAddr offset) noexcept {
+        return m_mappings.find(offset);
+    }
 private:
     Common::HostMemory& m_buffer;
     const s64 m_max_resident_map_count;
-
     std::shared_mutex m_rebuild_lock{};
     std::mutex m_lock{};
     s64 m_map_count{};