Implementing object table. Not complete, but better.

src/xenia/kernel/modules/xboxkrnl/kernel_state.cc

@@ -26,14 +26,12 @@ namespace {
 
 KernelState::KernelState(Runtime* runtime) :
     runtime_(runtime),
-    executable_module_(NULL),
-    next_handle_(0) {
+    executable_module_(NULL) {
   memory_     = runtime->memory();
   processor_  = runtime->processor();
   filesystem_ = runtime->filesystem();
 
-  objects_mutex_ = xe_mutex_alloc(0);
-  XEASSERTNOTNULL(objects_mutex_);
+  object_table_ = new ObjectTable();
 }
 
 KernelState::~KernelState() {
@@ -43,27 +41,7 @@ KernelState::~KernelState() {
   }
 
   // Delete all objects.
-  // We first copy the list to another list so that the deletion of the objects
-  // doesn't mess up iteration.
-  std::vector<XObject*> all_objects;
-  xe_mutex_lock(objects_mutex_);
-  for (std::tr1::unordered_map<X_HANDLE, XObject*>::iterator it =
-       objects_.begin(); it != objects_.end(); ++it) {
-    all_objects.push_back(it->second);
-  }
-  objects_.clear();
-  modules_.clear();
-  threads_.clear();
-  xe_mutex_unlock(objects_mutex_);
-  for (std::vector<XObject*>::iterator it = all_objects.begin();
-       it != all_objects.end(); ++it) {
-    // Perhaps call a special ForceRelease method or something?
-    XObject* obj = *it;
-    delete obj;
-  }
-
-  xe_mutex_free(objects_mutex_);
-  objects_mutex_ = NULL;
+  delete object_table_;
 
   filesystem_.reset();
   processor_.reset();
@@ -86,75 +64,31 @@ fs::FileSystem* KernelState::filesystem() {
   return filesystem_.get();
 }
 
-// TODO(benvanik): invesitgate better handle storage/structure.
-// A much better way of doing handles, if performance becomes an issue, would
-// be to try to make the pointers 32bit. Then we could round-trip them through
-// PPC code without needing to keep a map.
-// To achieve this we could try doing allocs in the 32-bit address space via
-// the OS alloc calls, or maybe create a section with a reserved size at load
-// time (65k handles * 4 is more than enough?).
-// We could then use a free list of handle IDs and allocate/release lock-free.
-
-XObject* KernelState::GetObject(X_HANDLE handle) {
-  xe_mutex_lock(objects_mutex_);
-  std::tr1::unordered_map<X_HANDLE, XObject*>::iterator it =
-      objects_.find(handle);
-  XObject* value = it != objects_.end() ? it->second : NULL;
-  if (value) {
-    value->Retain();
-  }
-  xe_mutex_unlock(objects_mutex_);
-  return value;
-}
-
-X_HANDLE KernelState::InsertObject(XObject* obj) {
-  xe_mutex_lock(objects_mutex_);
-  X_HANDLE handle = 0x00001000 + (++next_handle_);
-  objects_.insert(std::pair<X_HANDLE, XObject*>(handle, obj));
-  switch (obj->type()) {
-    case XObject::kTypeModule:
-      modules_.insert(std::pair<X_HANDLE, XModule*>(
-          handle, static_cast<XModule*>(obj)));
-      break;
-    case XObject::kTypeThread:
-      threads_.insert(std::pair<X_HANDLE, XThread*>(
-          handle, static_cast<XThread*>(obj)));
-      break;
-  }
-  xe_mutex_unlock(objects_mutex_);
-  return handle;
-}
-
-void KernelState::RemoveObject(XObject* obj) {
-  xe_mutex_lock(objects_mutex_);
-  objects_.erase(obj->handle());
-  xe_mutex_unlock(objects_mutex_);
+ObjectTable* KernelState::object_table() const {
+  return object_table_;
 }
 
 XModule* KernelState::GetModule(const char* name) {
-  XModule* found = NULL;
-  xe_mutex_lock(objects_mutex_);
-  for (std::tr1::unordered_map<X_HANDLE, XModule*>::iterator it =
-       modules_.begin(); it != modules_.end(); ++it) {
-    if (xestrcmpa(name, it->second->name()) == 0) {
-      found = it->second;
-      found->Retain();
-    }
-  }
-  xe_mutex_unlock(objects_mutex_);
-  return found;
-}
-
-XModule* KernelState::GetExecutableModule() {
-  if (executable_module_) {
-    executable_module_->Retain();
-    return executable_module_;
-  }
+  // TODO(benvanik): implement lookup. Most games seem to look for xam.xex/etc.
+  XEASSERTALWAYS();
   return NULL;
 }
 
+XModule* KernelState::GetExecutableModule() {
+  if (!executable_module_) {
+    return NULL;
+  }
+
+  executable_module_->Retain();
+  return executable_module_;
+}
+
 void KernelState::SetExecutableModule(XModule* module) {
-  if (executable_module_ && executable_module_ != module) {
+  if (module == executable_module_) {
+    return;
+  }
+
+  if (executable_module_) {
     executable_module_->Release();
   }
   executable_module_ = module;

src/xenia/kernel/modules/xboxkrnl/kernel_state.h

@@ -17,6 +17,7 @@
 #include <xenia/kernel/kernel_module.h>
 #include <xenia/kernel/xbox.h>
 #include <xenia/kernel/fs/filesystem.h>
+#include <xenia/kernel/modules/xboxkrnl/object_table.h>
 
 
 namespace xe {
@@ -24,9 +25,7 @@ namespace kernel {
 namespace xboxkrnl {
 
 
-class XObject;
 class XModule;
-class XThread;
 
 
 class KernelState {
@@ -39,7 +38,7 @@ public:
   cpu::Processor* processor();
   fs::FileSystem* filesystem();
 
-  XObject* GetObject(X_HANDLE handle);
+  ObjectTable* object_table() const;
 
   XModule* GetModule(const char* name);
   XModule* GetExecutableModule();
@@ -54,13 +53,9 @@ private:
   shared_ptr<cpu::Processor> processor_;
   shared_ptr<fs::FileSystem> filesystem_;
 
-  XModule*      executable_module_;
+  ObjectTable*  object_table_;
 
-  xe_mutex_t* objects_mutex_;
-  X_HANDLE next_handle_;
-  std::tr1::unordered_map<X_HANDLE, XObject*> objects_;
-  std::tr1::unordered_map<X_HANDLE, XModule*> modules_;
-  std::tr1::unordered_map<X_HANDLE, XThread*> threads_;
+  XModule*      executable_module_;
 
   friend class XObject;
 };

src/xenia/kernel/modules/xboxkrnl/object_table.cc

@@ -0,0 +1,178 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <xenia/kernel/modules/xboxkrnl/object_table.h>
+
+#include <xenia/kernel/modules/xboxkrnl/xobject.h>
+
+
+using namespace xe;
+using namespace xe::kernel;
+using namespace xe::kernel::xboxkrnl;
+
+
+ObjectTable::ObjectTable() :
+    table_capacity_(0),
+    table_(NULL),
+    last_free_entry_(0) {
+  table_mutex_ = xe_mutex_alloc(0);
+  XEASSERTNOTNULL(table_mutex_);
+}
+
+ObjectTable::~ObjectTable() {
+  xe_mutex_lock(table_mutex_);
+
+  // Release all objects.
+  for (uint32_t n = 0; n < table_capacity_; n++) {
+    ObjectTableEntry& entry = table_[n];
+    if (entry.object) {
+      entry.object->ReleaseHandle();
+    }
+  }
+
+  table_capacity_ = 0;
+  last_free_entry_ = 0;
+  xe_free(table_);
+  table_ = NULL;
+
+  xe_mutex_unlock(table_mutex_);
+
+  xe_mutex_free(table_mutex_);
+  table_mutex_ = NULL;
+}
+
+X_STATUS ObjectTable::FindFreeSlot(uint32_t* out_slot) {
+  // Find a free slot.
+  uint32_t slot = last_free_entry_;
+  uint32_t scan_count = 0;
+  while (scan_count < table_capacity_) {
+    ObjectTableEntry& entry = table_[slot];
+    if (!entry.object) {
+      *out_slot = slot;
+      return X_STATUS_SUCCESS;
+    }
+    scan_count++;
+    slot = (slot + 1) % table_capacity_;
+    if (slot == 0) {
+      // Never allow 0 handles.
+      scan_count++;
+      slot++;
+    }
+  }
+
+  // Table out of slots, expand.
+  uint32_t new_table_capacity = MAX(16 * 1024, table_capacity_ * 2);
+  ObjectTableEntry* new_table = (ObjectTableEntry*)xe_recalloc(
+      table_,
+      table_capacity_ * sizeof(ObjectTableEntry),
+      new_table_capacity * sizeof(ObjectTableEntry));
+  if (!new_table) {
+    return X_STATUS_NO_MEMORY;
+  }
+  last_free_entry_ = table_capacity_;
+  table_capacity_ = new_table_capacity;
+  table_ = new_table;
+
+  // Never allow 0 handles.
+  slot = ++last_free_entry_;
+  *out_slot = slot;
+
+  return X_STATUS_SUCCESS;
+}
+
+X_STATUS ObjectTable::AddHandle(XObject* object, X_HANDLE* out_handle) {
+  XEASSERTNOTNULL(out_handle);
+
+  X_STATUS result = X_STATUS_SUCCESS;
+
+  xe_mutex_lock(table_mutex_);
+
+  // Find a free slot.
+  uint32_t slot = 0;
+  result = FindFreeSlot(&slot);
+
+  // Stash.
+  if (XSUCCEEDED(result)) {
+    ObjectTableEntry& entry = table_[slot];
+    entry.object = object;
+
+    // Retain so long as the object is in the table.
+    object->RetainHandle();
+    object->Retain();
+  }
+
+  xe_mutex_unlock(table_mutex_);
+
+  if (XSUCCEEDED(result)) {
+    *out_handle = slot << 2;
+  }
+
+  return result;
+}
+
+X_STATUS ObjectTable::RemoveHandle(X_HANDLE handle) {
+  X_STATUS result = X_STATUS_SUCCESS;
+
+  xe_mutex_lock(table_mutex_);
+
+  // Lower 2 bits are ignored.
+  uint32_t slot = handle >> 2;
+
+  // Verify slot.
+  XObject* object = NULL;
+  if (slot > table_capacity_) {
+    result = X_STATUS_INVALID_HANDLE;
+  } else {
+    ObjectTableEntry& entry = table_[slot];
+    if (entry.object) {
+      object = entry.object;
+
+      // Release the object handle now that it is out of the table.
+      object->ReleaseHandle();
+      object->Release();
+    } else {
+      result = X_STATUS_INVALID_HANDLE;
+    }
+  }
+
+  xe_mutex_unlock(table_mutex_);
+
+  return result;
+}
+
+X_STATUS ObjectTable::GetObject(X_HANDLE handle, XObject** out_object) {
+  XEASSERTNOTNULL(out_object);
+
+  X_STATUS result = X_STATUS_SUCCESS;
+
+  xe_mutex_lock(table_mutex_);
+
+  // Lower 2 bits are ignored.
+  uint32_t slot = handle >> 2;
+
+  // Verify slot.
+  XObject* object = NULL;
+  if (slot > table_capacity_) {
+    result = X_STATUS_INVALID_HANDLE;
+  } else {
+    ObjectTableEntry& entry = table_[slot];
+    if (entry.object) {
+      object = entry.object;
+    } else {
+      result = X_STATUS_INVALID_HANDLE;
+    }
+  }
+
+  // Retain the object pointer.
+  object->Retain();
+
+  xe_mutex_unlock(table_mutex_);
+
+  return result;
+}

src/xenia/kernel/modules/xboxkrnl/object_table.h

@@ -0,0 +1,55 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_KERNEL_MODULES_XBOXKRNL_OBJECT_TABLE_H_
+#define XENIA_KERNEL_MODULES_XBOXKRNL_OBJECT_TABLE_H_
+
+#include <xenia/common.h>
+#include <xenia/core.h>
+
+#include <xenia/kernel/xbox.h>
+
+
+namespace xe {
+namespace kernel {
+namespace xboxkrnl {
+
+
+class XObject;
+
+
+class ObjectTable {
+public:
+  ObjectTable();
+  ~ObjectTable();
+
+  X_STATUS AddHandle(XObject* object, X_HANDLE* out_handle);
+  X_STATUS RemoveHandle(X_HANDLE handle);
+  X_STATUS GetObject(X_HANDLE handle, XObject** out_object);
+
+private:
+  X_STATUS FindFreeSlot(uint32_t* out_slot);
+
+  typedef struct {
+    XObject* object;
+  } ObjectTableEntry;
+
+  xe_mutex_t*       table_mutex_;
+  uint32_t          table_capacity_;
+  ObjectTableEntry* table_;
+  uint32_t          last_free_entry_;
+};
+
+
+}  // namespace xboxkrnl
+}  // namespace kernel
+}  // namespace xe
+
+
+#endif  // XENIA_KERNEL_MODULES_XBOXKRNL_OBJECT_TABLE_H_

src/xenia/kernel/modules/xboxkrnl/sources.gypi

@@ -5,6 +5,8 @@
     'kernel_state.h',
     'module.cc',
     'module.h',
+    'object_table.cc',
+    'object_table.h',
     'xboxkrnl_debug.cc',
     'xboxkrnl_debug.h',
     'xboxkrnl_hal.cc',

src/xenia/kernel/modules/xboxkrnl/xobject.cc

@@ -17,18 +17,15 @@ using namespace xe::kernel::xboxkrnl;
 
 XObject::XObject(KernelState* kernel_state, Type type) :
     kernel_state_(kernel_state),
-    ref_count_(1),
+    handle_ref_count_(0),
+    pointer_ref_count_(0),
     type_(type), handle_(X_INVALID_HANDLE_VALUE) {
-  handle_ = kernel_state->InsertObject(this);
+  kernel_state->object_table()->AddHandle(this, &handle_);
 }
 
 XObject::~XObject() {
-  XEASSERTZERO(ref_count_);
-
-  if (handle_ != X_INVALID_HANDLE_VALUE) {
-    // Remove from state table.
-    kernel_state_->RemoveObject(this);
-  }
+  XEASSERTZERO(handle_ref_count_);
+  XEASSERTZERO(pointer_ref_count_);
 }
 
 Runtime* XObject::runtime() {
@@ -47,16 +44,28 @@ XObject::Type XObject::type() {
   return type_;
 }
 
-X_HANDLE XObject::handle() {
+X_HANDLE XObject::handle() const {
   return handle_;
 }
 
+void XObject::RetainHandle() {
+  xe_atomic_inc_32(&handle_ref_count_);
+}
+
+bool XObject::ReleaseHandle() {
+  if (!xe_atomic_dec_32(&handle_ref_count_)) {
+    return true;
+  }
+  return false;
+}
+
 void XObject::Retain() {
-  xe_atomic_inc_32(&ref_count_);
+  xe_atomic_inc_32(&pointer_ref_count_);
 }
 
 void XObject::Release() {
-  if (!xe_atomic_dec_32(&ref_count_)) {
+  if (!xe_atomic_dec_32(&pointer_ref_count_)) {
+    XEASSERT(pointer_ref_count_ >= handle_ref_count_);
     delete this;
   }
 }

src/xenia/kernel/modules/xboxkrnl/xobject.h

@@ -40,8 +40,10 @@ public:
   KernelState* kernel_state();
 
   Type type();
-  X_HANDLE handle();
+  X_HANDLE handle() const;
 
+  void RetainHandle();
+  bool ReleaseHandle();
   void Retain();
   void Release();
 
@@ -52,7 +54,8 @@ protected:
 private:
   KernelState*  kernel_state_;
 
-  volatile int32_t ref_count_;
+  volatile int32_t handle_ref_count_;
+  volatile int32_t pointer_ref_count_;
 
   Type          type_;
   X_HANDLE      handle_;