Angelscript/add_on/weakref/weakref.cpp

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2021-04-12 18:25:02 +00:00
// The CScriptWeakRef class was originally implemented by vroad in March 2013
#include "weakref.h"
#include <new>
#include <assert.h>
#include <string.h> // strstr()
BEGIN_AS_NAMESPACE
static void ScriptWeakRefConstruct(asITypeInfo *type, void *mem)
{
new(mem) CScriptWeakRef(type);
}
static void ScriptWeakRefConstruct2(asITypeInfo *type, void *ref, void *mem)
{
new(mem) CScriptWeakRef(ref, type);
// It's possible the constructor raised a script exception, in which case we
// need to call the destructor in order to cleanup the memory before returning
asIScriptContext *ctx = asGetActiveContext();
if( ctx && ctx->GetState() == asEXECUTION_EXCEPTION )
reinterpret_cast<CScriptWeakRef*>(mem)->~CScriptWeakRef();
}
static void ScriptWeakRefDestruct(CScriptWeakRef *obj)
{
obj->~CScriptWeakRef();
}
static bool ScriptWeakRefTemplateCallback(asITypeInfo *ti, bool &/*dontGarbageCollect*/)
{
asITypeInfo *subType = ti->GetSubType();
// Weak references only work for reference types
if( subType == 0 ) return false;
if( !(subType->GetFlags() & asOBJ_REF) ) return false;
// The subtype shouldn't be a handle
if( ti->GetSubTypeId() & asTYPEID_OBJHANDLE )
return false;
// Make sure the type really supports weak references
asUINT cnt = subType->GetBehaviourCount();
for( asUINT n = 0; n < cnt; n++ )
{
asEBehaviours beh;
subType->GetBehaviourByIndex(n, &beh);
if( beh == asBEHAVE_GET_WEAKREF_FLAG )
return true;
}
ti->GetEngine()->WriteMessage("weakref", 0, 0, asMSGTYPE_ERROR, "The subtype doesn't support weak references");
return false;
}
CScriptWeakRef::CScriptWeakRef(asITypeInfo *type)
{
m_ref = 0;
m_type = type;
m_type->AddRef();
m_weakRefFlag = 0;
}
CScriptWeakRef::CScriptWeakRef(const CScriptWeakRef &other)
{
m_ref = other.m_ref;
m_type = other.m_type;
m_type->AddRef();
m_weakRefFlag = other.m_weakRefFlag;
if( m_weakRefFlag )
m_weakRefFlag->AddRef();
}
CScriptWeakRef::CScriptWeakRef(void *ref, asITypeInfo *type)
{
m_ref = ref;
m_type = type;
m_type->AddRef();
// The given type should be the weakref template instance
assert( strcmp(type->GetName(), "weakref") == 0 ||
strcmp(type->GetName(), "const_weakref") == 0 );
// Get the shared flag that will tell us when the object has been destroyed
// This is threadsafe as we hold a strong reference to the object
m_weakRefFlag = m_type->GetEngine()->GetWeakRefFlagOfScriptObject(m_ref, m_type->GetSubType());
if( m_weakRefFlag )
m_weakRefFlag->AddRef();
}
CScriptWeakRef::~CScriptWeakRef()
{
if( m_type )
m_type->Release();
if( m_weakRefFlag )
m_weakRefFlag->Release();
}
CScriptWeakRef &CScriptWeakRef::operator =(const CScriptWeakRef &other)
{
// Don't do anything if it is the same reference
// It is not enough to verify only the reference to the object, as the
// address may be reused by another instance after the first has been freed.
// By checking also the weakRefFlag we can be certain that it is the same
// instance.
if( m_ref == other.m_ref &&
m_weakRefFlag == other.m_weakRefFlag )
return *this;
// Must not allow changing the type
if( m_type != other.m_type )
{
// We can allow a weakref to be assigned to a const_weakref
if( !(strcmp(m_type->GetName(), "const_weakref") == 0 &&
strcmp(other.m_type->GetName(), "weakref") == 0 &&
m_type->GetSubType() == other.m_type->GetSubType()) )
{
assert( false );
return *this;
}
}
m_ref = other.m_ref;
if( m_weakRefFlag )
m_weakRefFlag->Release();
m_weakRefFlag = other.m_weakRefFlag;
if( m_weakRefFlag )
m_weakRefFlag->AddRef();
return *this;
}
CScriptWeakRef &CScriptWeakRef::Set(void *newRef)
{
// Release the previous weak ref
if( m_weakRefFlag )
m_weakRefFlag->Release();
// Retrieve the new weak ref
m_ref = newRef;
if( newRef )
{
m_weakRefFlag = m_type->GetEngine()->GetWeakRefFlagOfScriptObject(newRef, m_type->GetSubType());
m_weakRefFlag->AddRef();
}
else
m_weakRefFlag = 0;
// Release the newRef since we're only supposed to hold a weakref
m_type->GetEngine()->ReleaseScriptObject(newRef, m_type->GetSubType());
return *this;
}
asITypeInfo *CScriptWeakRef::GetRefType() const
{
return m_type->GetSubType();
}
bool CScriptWeakRef::operator==(const CScriptWeakRef &o) const
{
// It is not enough to compare just the address of the object, as it may
// be reused by another instance after the first has been freed. By verifying
// also the weakRefFlag we can guarantee that it is indeed the same instance.
if( m_ref == o.m_ref &&
m_weakRefFlag == o.m_weakRefFlag &&
m_type == o.m_type )
return true;
// TODO: If type is not the same, we should attempt to do a dynamic cast,
// which may change the pointer for application registered classes
return false;
}
bool CScriptWeakRef::operator!=(const CScriptWeakRef &o) const
{
return !(*this == o);
}
// AngelScript: used as '@obj = ref.get();'
void *CScriptWeakRef::Get() const
{
// If we hold a null handle, then just return null
if( m_ref == 0 || m_weakRefFlag == 0 )
return 0;
// Lock on the shared bool, so we can be certain it won't be changed to true
// between the inspection of the flag and the increase of the ref count in the
// owning object.
m_weakRefFlag->Lock();
if( !m_weakRefFlag->Get() )
{
m_type->GetEngine()->AddRefScriptObject(m_ref, m_type->GetSubType());
m_weakRefFlag->Unlock();
return m_ref;
}
m_weakRefFlag->Unlock();
return 0;
}
bool CScriptWeakRef::Equals(void *ref) const
{
if( m_ref != ref )
return false;
// It is not enough to compare just the address, as another instance may
// get the same address after the first instance has been freed. Verify the
// weakref flag too to make sure it is the same instance
asILockableSharedBool *flag = m_type->GetEngine()->GetWeakRefFlagOfScriptObject(ref, m_type->GetSubType());
if (m_weakRefFlag != flag)
return false;
return true;
}
void RegisterScriptWeakRef_Native(asIScriptEngine *engine)
{
int r;
// Register a type for non-const handles
r = engine->RegisterObjectType("weakref<class T>", sizeof(CScriptWeakRef), asOBJ_VALUE | asOBJ_ASHANDLE | asOBJ_TEMPLATE | asOBJ_APP_CLASS_DAK); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in)", asFUNCTION(ScriptWeakRefConstruct), asCALL_CDECL_OBJLAST); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in, T@+)", asFUNCTION(ScriptWeakRefConstruct2), asCALL_CDECL_OBJLAST); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_DESTRUCT, "void f()", asFUNCTION(ScriptWeakRefDestruct), asCALL_CDECL_OBJLAST); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_TEMPLATE_CALLBACK, "bool f(int&in, bool&out)", asFUNCTION(ScriptWeakRefTemplateCallback), asCALL_CDECL); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "T@ opImplCast()", asMETHOD(CScriptWeakRef, Get), asCALL_THISCALL); assert(r >= 0);
r = engine->RegisterObjectMethod("weakref<T>", "T@ get() const", asMETHODPR(CScriptWeakRef, Get, () const, void*), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opHndlAssign(const weakref<T> &in)", asMETHOD(CScriptWeakRef, operator=), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opAssign(const weakref<T> &in)", asMETHOD(CScriptWeakRef, operator=), asCALL_THISCALL); assert(r >= 0);
r = engine->RegisterObjectMethod("weakref<T>", "bool opEquals(const weakref<T> &in) const", asMETHODPR(CScriptWeakRef, operator==, (const CScriptWeakRef &) const, bool), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opHndlAssign(T@)", asMETHOD(CScriptWeakRef, Set), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "bool opEquals(const T@+) const", asMETHOD(CScriptWeakRef, Equals), asCALL_THISCALL); assert(r >= 0);
// Register another type for const handles
r = engine->RegisterObjectType("const_weakref<class T>", sizeof(CScriptWeakRef), asOBJ_VALUE | asOBJ_ASHANDLE | asOBJ_TEMPLATE | asOBJ_APP_CLASS_DAK); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in)", asFUNCTION(ScriptWeakRefConstruct), asCALL_CDECL_OBJLAST); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in, const T@+)", asFUNCTION(ScriptWeakRefConstruct2), asCALL_CDECL_OBJLAST); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_DESTRUCT, "void f()", asFUNCTION(ScriptWeakRefDestruct), asCALL_CDECL_OBJLAST); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_TEMPLATE_CALLBACK, "bool f(int&in, bool&out)", asFUNCTION(ScriptWeakRefTemplateCallback), asCALL_CDECL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const T@ opImplCast() const", asMETHOD(CScriptWeakRef, Get), asCALL_THISCALL); assert(r >= 0);
r = engine->RegisterObjectMethod("const_weakref<T>", "const T@ get() const", asMETHODPR(CScriptWeakRef, Get, () const, void*), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const const_weakref<T> &in)", asMETHOD(CScriptWeakRef, operator=), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opAssign(const const_weakref<T> &in)", asMETHOD(CScriptWeakRef, operator=), asCALL_THISCALL); assert(r >= 0);
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const const_weakref<T> &in) const", asMETHODPR(CScriptWeakRef, operator==, (const CScriptWeakRef &) const, bool), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const T@)", asMETHOD(CScriptWeakRef, Set), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const T@+) const", asMETHOD(CScriptWeakRef, Equals), asCALL_THISCALL); assert(r >= 0);
// Allow non-const weak references to be converted to const weak references
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const weakref<T> &in)", asMETHOD(CScriptWeakRef, operator=), asCALL_THISCALL); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const weakref<T> &in) const", asMETHODPR(CScriptWeakRef, operator==, (const CScriptWeakRef &) const, bool), asCALL_THISCALL); assert( r >= 0 );
}
static void ScriptWeakRefConstruct_Generic(asIScriptGeneric *gen)
{
asITypeInfo *ti = *reinterpret_cast<asITypeInfo**>(gen->GetAddressOfArg(0));
ScriptWeakRefConstruct(ti, gen->GetObject());
}
static void ScriptWeakRefConstruct2_Generic(asIScriptGeneric *gen)
{
asITypeInfo *ti = *reinterpret_cast<asITypeInfo**>(gen->GetAddressOfArg(0));
void *ref = gen->GetArgAddress(1);
ScriptWeakRefConstruct2(ti, ref, gen->GetObject());
}
static void ScriptWeakRefDestruct_Generic(asIScriptGeneric *gen)
{
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
self->~CScriptWeakRef();
}
void CScriptWeakRef_Get_Generic(asIScriptGeneric *gen)
{
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
gen->SetReturnAddress(self->Get());
}
void CScriptWeakRef_Assign_Generic(asIScriptGeneric *gen)
{
CScriptWeakRef *other = reinterpret_cast<CScriptWeakRef*>(gen->GetArgAddress(0));
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
*self = *other;
gen->SetReturnAddress(self);
}
void CScriptWeakRef_Assign2_Generic(asIScriptGeneric *gen)
{
void *other = gen->GetArgAddress(0);
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
self->Set(other);
gen->SetReturnAddress(self);
}
void CScriptWeakRef_Equals_Generic(asIScriptGeneric *gen)
{
CScriptWeakRef *other = reinterpret_cast<CScriptWeakRef*>(gen->GetArgAddress(0));
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
gen->SetReturnByte(*self == *other);
}
void CScriptWeakRef_Equals2_Generic(asIScriptGeneric *gen)
{
void *other = gen->GetArgAddress(0);
CScriptWeakRef *self = reinterpret_cast<CScriptWeakRef*>(gen->GetObject());
gen->SetReturnByte(self->Equals(other));
}
static void ScriptWeakRefTemplateCallback_Generic(asIScriptGeneric *gen)
{
asITypeInfo *ti = *reinterpret_cast<asITypeInfo**>(gen->GetAddressOfArg(0));
bool *dontGarbageCollect = *reinterpret_cast<bool**>(gen->GetAddressOfArg(1));
*reinterpret_cast<bool*>(gen->GetAddressOfReturnLocation()) = ScriptWeakRefTemplateCallback(ti, *dontGarbageCollect);
}
void RegisterScriptWeakRef_Generic(asIScriptEngine *engine)
{
int r;
// Register a type for non-const handles
r = engine->RegisterObjectType("weakref<class T>", sizeof(CScriptWeakRef), asOBJ_VALUE | asOBJ_ASHANDLE | asOBJ_TEMPLATE | asOBJ_APP_CLASS_DAK); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in)", asFUNCTION(ScriptWeakRefConstruct_Generic), asCALL_GENERIC); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in, T@+)", asFUNCTION(ScriptWeakRefConstruct2_Generic), asCALL_GENERIC); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_TEMPLATE_CALLBACK, "bool f(int&in, bool&out)", asFUNCTION(ScriptWeakRefTemplateCallback_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("weakref<T>", asBEHAVE_DESTRUCT, "void f()", asFUNCTION(ScriptWeakRefDestruct_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "T@ opImplCast()", asFUNCTION(CScriptWeakRef_Get_Generic), asCALL_GENERIC); assert(r >= 0);
r = engine->RegisterObjectMethod("weakref<T>", "T@ get() const", asFUNCTION(CScriptWeakRef_Get_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opHndlAssign(const weakref<T> &in)", asFUNCTION(CScriptWeakRef_Assign_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opAssign(const weakref<T> &in)", asFUNCTION(CScriptWeakRef_Assign_Generic), asCALL_GENERIC); assert(r >= 0);
r = engine->RegisterObjectMethod("weakref<T>", "bool opEquals(const weakref<T> &in) const", asFUNCTION(CScriptWeakRef_Equals_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "weakref<T> &opHndlAssign(T@)", asFUNCTION(CScriptWeakRef_Assign2_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("weakref<T>", "bool opEquals(const T@+) const", asFUNCTION(CScriptWeakRef_Equals2_Generic), asCALL_GENERIC); assert(r >= 0);
// Register another type for const handles
r = engine->RegisterObjectType("const_weakref<class T>", sizeof(CScriptWeakRef), asOBJ_VALUE | asOBJ_ASHANDLE | asOBJ_TEMPLATE | asOBJ_APP_CLASS_DAK); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in)", asFUNCTION(ScriptWeakRefConstruct_Generic), asCALL_GENERIC); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_CONSTRUCT, "void f(int&in, const T@+)", asFUNCTION(ScriptWeakRefConstruct2_Generic), asCALL_GENERIC); assert( r>= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_TEMPLATE_CALLBACK, "bool f(int&in, bool&out)", asFUNCTION(ScriptWeakRefTemplateCallback_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectBehaviour("const_weakref<T>", asBEHAVE_DESTRUCT, "void f()", asFUNCTION(ScriptWeakRefDestruct_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const T@ opImplCast() const", asFUNCTION(CScriptWeakRef_Get_Generic), asCALL_GENERIC); assert(r >= 0);
r = engine->RegisterObjectMethod("const_weakref<T>", "const T@ get() const", asFUNCTION(CScriptWeakRef_Get_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const const_weakref<T> &in)", asFUNCTION(CScriptWeakRef_Assign_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opAssign(const const_weakref<T> &in)", asFUNCTION(CScriptWeakRef_Assign_Generic), asCALL_GENERIC); assert(r >= 0);
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const const_weakref<T> &in) const", asFUNCTION(CScriptWeakRef_Equals_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const T@)", asFUNCTION(CScriptWeakRef_Assign2_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const T@+) const", asFUNCTION(CScriptWeakRef_Equals2_Generic), asCALL_GENERIC); assert(r >= 0);
// Allow non-const weak references to be converted to const weak references
r = engine->RegisterObjectMethod("const_weakref<T>", "const_weakref<T> &opHndlAssign(const weakref<T> &in)", asFUNCTION(CScriptWeakRef_Assign_Generic), asCALL_GENERIC); assert( r >= 0 );
r = engine->RegisterObjectMethod("const_weakref<T>", "bool opEquals(const weakref<T> &in) const", asFUNCTION(CScriptWeakRef_Equals_Generic), asCALL_GENERIC); assert( r >= 0 );
}
void RegisterScriptWeakRef(asIScriptEngine *engine)
{
if( strstr(asGetLibraryOptions(), "AS_MAX_PORTABILITY") )
RegisterScriptWeakRef_Generic(engine);
else
RegisterScriptWeakRef_Native(engine);
}
END_AS_NAMESPACE