Performance optimisation for directors for classes passed by value

The directorin typemaps in the director methods now use std::move on the
input parameter when copying the object from the stack to the heap prior
to the callback into the target language, thereby taking advantage of
move semantics if available.

CHANGES.current

@@ -7,6 +7,12 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2022-07-03: wsfulton
+            Performane optimisation for directors for classes passed by value. The directorin
+            typemaps in the director methods now use std::move on the input parameter when
+            copying the object from the stack to the heap prior to the callback into the target
+            language, thereby taking advantage of move semantics if available.
+
 2022-07-02: wsfulton
             #1722 [C#, Java, Python, Ruby] Add std::unique_ptr support. Ported from std::auto_ptr.
             Use the %unique_ptr(T) macro as follows for usage std::unique_ptr<T>. For example, for

Examples/test-suite/csharp/director_pass_by_value_runme.cs

@@ -28,6 +28,8 @@ public class runme
           break;
       };
     }
+    if (director_pass_by_value.has_cplusplus11())
+      Counter.check_counts(1, 0, 0, 1, 0, 1); // check move constructor called and just one destructor
     // bug was the passByVal 'global' object was destroyed after the call to virtualMethod had finished.
     int ret = runme.passByVal.getVal();
     if (ret != 0x12345678)

Examples/test-suite/director_pass_by_value.i

@@ -1,14 +1,38 @@
 %module(directors="1") director_pass_by_value
+
+#if defined(SWIGD)
+%rename(trace) debug;
+#endif
+
 %director DirectorPassByValueAbstractBase;
 
+%include "cpp11_move_only_helper.i"
+
+%ignore PassedByValue::operator=;
+%ignore PassedByValue::PassedByValue(PassedByValue &&);
+
 %inline %{
-class PassedByValue {
-  int val;
-public:
-  PassedByValue() { val = 0x12345678; }
+#include <iostream>
+using namespace std;
+int debug = false;
+struct PassedByValue {
+  PassedByValue(int v = 0x12345678) { val = v; if (debug) cout << "PassedByValue(0x" << hex << val << ")" << " " << this << endl; Counter::normal_constructor++; }
+
+  PassedByValue(const PassedByValue &other) { val = other.val; if (debug) cout << "PassedByValue(const PassedByValue &)" << " " << this << " " << &other << endl; Counter::copy_constructor++;}
+  PassedByValue & operator=(const PassedByValue &other) { val = other.val; if (debug) cout << "operator=(const PassedByValue &)" << " " << this << " " << &other << endl; Counter::copy_assignment++; return *this; }
+
+#if __cplusplus >= 201103L
+  PassedByValue(PassedByValue &&other) noexcept { val = other.val; if (debug) cout << "PassedByValue(PassedByValue &&)" << " " << this << endl; Counter::move_constructor++; }
+  PassedByValue & operator=(PassedByValue &&other) noexcept { val = other.val; if (debug) cout << "operator=(PassedByValue &&)" << " " << this << endl; Counter::move_assignment++; return *this; }
+  ~PassedByValue() { if (debug) cout << "~PassedByValue()" << " " << this << endl; Counter::destructor++; }
+#endif
+
   int getVal() { return val; }
+private:
+  int val;
 };
 
+
 int doSomething(int x) {
   int yy[256];
   yy[0] =0x9876;
@@ -18,6 +42,7 @@ int doSomething(int x) {
 class DirectorPassByValueAbstractBase {
 public:
   virtual void virtualMethod(PassedByValue pbv) = 0;
+  virtual void virtualConstMethod(const PassedByValue pbv) {}
   virtual ~DirectorPassByValueAbstractBase () {}
 };
 
@@ -27,4 +52,12 @@ public:
     f.virtualMethod(PassedByValue());
   }
 };
+
+bool has_cplusplus11() {
+#if __cplusplus >= 201103L
+  return true;
+#else
+  return false;
+#endif
+}
 %}

Examples/test-suite/java/director_pass_by_value_runme.java

@@ -32,6 +32,8 @@ public class director_pass_by_value_runme {
           break;
       };
     }
+    if (director_pass_by_value.has_cplusplus11())
+      Counter.check_counts(1, 0, 0, 1, 0, 1); // check move constructor called and just one destructor
     // bug was the passByVal 'global' object was destroyed after the call to virtualMethod had finished.
     int ret = director_pass_by_value_runme.passByVal.getVal();
     if (ret != 0x12345678)

Examples/test-suite/ocaml/director_pass_by_value_runme.ml

@@ -14,10 +14,13 @@ let d =
     (director_pass_by_value_Derived)
     '()
 
+let cpp11 = _has_cplusplus11 '() as bool
+
 let _ =
   let caller = new_Caller '() in
   assert (caller -> call_virtualMethod (d) = C_void);
   assert (Array.length !passByVal = 1);
+(* TODO: only run if cpp11... let _ = _Counter_check_counts (C_list [C_int 0; C_int 0; C_int 0; C_int 1; C_int 0; C_int 1]) in*) (* check move constructor called and just one destructor *)
   let a = List.hd (fnhelper (!passByVal.(0))) in
   assert (a -> getVal () as int = 0x12345678);
   assert (a -> "~" () = C_void);

Examples/test-suite/php/director_pass_by_value_runme.php

@@ -14,6 +14,9 @@ class director_pass_by_value_Derived extends DirectorPassByValueAbstractBase {
 # bug was the passByVal global object was destroyed after the call to virtualMethod had finished.
 $caller = new Caller();
 $caller->call_virtualMethod(new director_pass_by_value_Derived());
+if (has_cplusplus11()) {
+  Counter::check_counts(1, 0, 0, 1, 0, 1); # check move constructor called and just one destructor
+}
 $ret = $passByVal->getVal();
 if ($ret != 0x12345678) {
   check::fail("Bad return value, got " . dechex($ret));

Examples/test-suite/python/director_pass_by_value_runme.py

@@ -8,6 +8,8 @@ class director_pass_by_value_Derived(director_pass_by_value.DirectorPassByValueA
 
 # bug was the passByVal global object was destroyed after the call to virtualMethod had finished.
 director_pass_by_value.Caller().call_virtualMethod(director_pass_by_value_Derived())
+if director_pass_by_value.has_cplusplus11():
+    director_pass_by_value.Counter.check_counts(1, 0, 0, 1, 0, 1) # check move constructor called and just one destructor
 ret = passByVal.getVal();
 if ret != 0x12345678:
   raise RuntimeError("Bad return value, got " + hex(ret))

Lib/csharp/boost_shared_ptr.i

@@ -32,7 +32,7 @@
 %{ $result = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1)); %}
 
 %typemap(directorin) CONST TYPE
-%{ $input = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype((const $1_ltype &)$1)); %}
+%{ $input = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype(SWIG_STD_MOVE($1))); %}
 
 %typemap(directorout) CONST TYPE
 %{ if (!$input) {

Lib/csharp/csharp.swg

@@ -409,7 +409,7 @@ SWIGINTERN const char * SWIG_UnpackData(const char *c, void *ptr, size_t sz) {
 #endif
 
 %typemap(directorin) SWIGTYPE 
-%{ $input = (void *)new $1_ltype((const $1_ltype &)$1); %}
+%{ $input = (void *)new $1_ltype(SWIG_STD_MOVE($1)); %}
 %typemap(csdirectorin) SWIGTYPE "new $&csclassname($iminput, true)"
 %typemap(csdirectorout) SWIGTYPE "$&csclassname.getCPtr($cscall).Handle"
 

Lib/d/boost_shared_ptr.i

@@ -26,7 +26,7 @@
 %{ $result = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1)); %}
 
 %typemap(directorin) CONST TYPE
-%{ $input = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype((const $1_ltype &)$1)); %}
+%{ $input = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype(SWIG_STD_MOVE($1))); %}
 
 %typemap(directorout) CONST TYPE
 %{ if (!$input) {

Lib/d/dswigtype.swg

@@ -62,7 +62,7 @@
 #endif
 
 %typemap(directorin) SWIGTYPE
-  "$input = (void *)new $1_ltype((const $1_ltype &)$1);"
+  "$input = (void *)new $1_ltype(SWIG_STD_MOVE($1));"
 %typemap(directorout) SWIGTYPE
 %{ if (!$input) {
      SWIG_DSetPendingException(SWIG_DIllegalArgumentException, "Unexpected null return for type $1_type");

Lib/go/go.swg

@@ -625,7 +625,7 @@
 %typemap(goout) SWIGTYPE ""
 
 %typemap(directorin) SWIGTYPE
-%{ $input = new $1_ltype((const $1_ltype &)$1); %}
+%{ $input = new $1_ltype(SWIG_STD_MOVE($1)); %}
 
 %typemap(godirectorin) SWIGTYPE ""
 

Lib/java/boost_shared_ptr.i

@@ -33,7 +33,7 @@
 
 %typemap(directorin,descriptor="L$packagepath/$&javaclassname;") CONST TYPE
 %{ $input = 0;
-  *((SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > **)&$input) = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype((const $1_ltype &)$1)); %}
+  *((SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > **)&$input) = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > (new $1_ltype(SWIG_STD_MOVE($1))); %}
 
 %typemap(directorout) CONST TYPE
 %{ if (!$input) {

Lib/java/java.swg

@@ -676,7 +676,7 @@ Swig::LocalRefGuard $1_refguard(jenv, $input); }
 
 %typemap(directorin,descriptor="L$packagepath/$&javaclassname;") SWIGTYPE 
 %{ $input = 0;
-   *(($&1_ltype*)&$input) = new $1_ltype((const $1_ltype &)$1); %}
+   *(($&1_ltype*)&$input) = new $1_ltype(SWIG_STD_MOVE($1)); %}
 %typemap(javadirectorin) SWIGTYPE "new $&javaclassname($jniinput, true)"
 %typemap(javadirectorout) SWIGTYPE "$&javaclassname.getCPtr($javacall)"
 

Lib/java/swiginterface.i

@@ -40,7 +40,7 @@
 %typemap(javadirectorout) CTYPE *const& "$javacall.$*interfacename_GetInterfaceCPtr()"
 %typemap(directorin,descriptor="L$packagepath/$&javainterfacename;") CTYPE
 %{ $input = 0;
-   *(($&1_ltype*)&$input) = new $1_ltype((const $1_ltype &)$1); %}
+   *(($&1_ltype*)&$input) = new $1_ltype(SWIG_STD_MOVE($1)); %}
 %typemap(directorin,descriptor="L$packagepath/$javainterfacename;") CTYPE *, CTYPE []
 %{ *(($&1_ltype)&$input) = ($1_ltype) $1; %}
 %typemap(directorin,descriptor="L$packagepath/$javainterfacename;") CTYPE &

Lib/ocaml/ocaml.swg

@@ -119,7 +119,7 @@
 }
 
 %typemap(directorin) SWIGTYPE {
-    $&ltype temp = new $ltype((const $ltype &)$1);
+    $&ltype temp = new $1_ltype(SWIG_STD_MOVE($1));
     swig_result = SWIG_Ocaml_ptr_to_val("create_$ltype_from_ptr", (void *)temp, $&1_descriptor);
     args = caml_list_append(args, swig_result);
 }

Lib/octave/boost_shared_ptr.i

@@ -59,7 +59,7 @@
 }
 
 %typemap(directorin,noblock=1) CONST TYPE (SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > *smartarg = 0) %{
-  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1));
+  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(SWIG_STD_MOVE($1)));
   $input = SWIG_NewPointerObj(%as_voidptr(smartarg), $descriptor(SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< TYPE > *), SWIG_POINTER_OWN | %newpointer_flags);
 %}
 %typemap(directorout,noblock=1) CONST TYPE (void *swig_argp, int swig_res = 0) {

Lib/php/php.swg

@@ -454,7 +454,7 @@
 %typemap(directorin) SWIGTYPE
 %{
   ZVAL_UNDEF($input);
-  SWIG_SetPointerZval($input, SWIG_as_voidptr(new $1_ltype((const $1_ltype &)$1)), $&1_descriptor, 1);
+  SWIG_SetPointerZval($input, SWIG_as_voidptr(new $1_ltype(SWIG_STD_MOVE($1))), $&1_descriptor, 1);
 %}
 
 %typemap(out, phptype="void") void "";

Lib/python/boost_shared_ptr.i

@@ -63,7 +63,7 @@
 }
 
 %typemap(directorin,noblock=1) CONST TYPE (SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > *smartarg = 0) %{
-  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1));
+  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(SWIG_STD_MOVE($1)));
   $input = SWIG_NewPointerObj(%as_voidptr(smartarg), $descriptor(SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< TYPE > *), SWIG_POINTER_OWN | %newpointer_flags);
 %}
 %typemap(directorout,noblock=1) CONST TYPE (void *swig_argp, int swig_res = 0) {

Lib/r/boost_shared_ptr.i

@@ -59,7 +59,7 @@
 }
 
 %typemap(directorin,noblock=1) CONST TYPE (SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > *smartarg = 0) %{
-  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1));
+  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(SWIG_STD_MOVE($1)));
   $input = SWIG_NewPointerObj(%as_voidptr(smartarg), $descriptor(SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< TYPE > *), SWIG_POINTER_OWN | %newpointer_flags);
 %}
 %typemap(directorout,noblock=1) CONST TYPE (void *swig_argp, int swig_res = 0) {

Lib/ruby/boost_shared_ptr.i

@@ -59,7 +59,7 @@
 }
 
 %typemap(directorin,noblock=1) CONST TYPE (SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > *smartarg = 0) %{
-  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1));
+  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(SWIG_STD_MOVE($1)));
   $input = SWIG_NewPointerObj(%as_voidptr(smartarg), $descriptor(SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< TYPE > *), SWIG_POINTER_OWN | %newpointer_flags);
 %}
 %typemap(directorout,noblock=1) CONST TYPE (void *swig_argp, int swig_res = 0) {

Lib/scilab/boost_shared_ptr.i

@@ -59,7 +59,7 @@
 }
 
 %typemap(directorin,noblock=1) CONST TYPE (SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE > *smartarg = 0) %{
-  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(($1_ltype &)$1));
+  smartarg = new SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< CONST TYPE >(new $1_ltype(SWIG_STD_MOVE($1)));
   $input = SWIG_NewPointerObj(%as_voidptr(smartarg), $descriptor(SWIG_SHARED_PTR_QNAMESPACE::shared_ptr< TYPE > *), SWIG_POINTER_OWN | %newpointer_flags);
 %}
 %typemap(directorout,noblock=1) CONST TYPE (void *swig_argp, int swig_res = 0) {

Lib/swig.swg

@@ -703,6 +703,15 @@ public:
 template <typename T> T SwigValueInit() {
   return T();
 }
+%}
+
+%insert("runtime") %{
+#if __cplusplus >=201103L
+# define SWIG_STD_MOVE(OBJ) std::move(OBJ)
+#else
+# define SWIG_STD_MOVE(OBJ) OBJ
+#endif
+
 #endif
 %}
 #endif

Lib/typemaps/swigtype.swg

@@ -417,7 +417,7 @@
 /* directorin */
 
 %typemap(directorin,noblock=1) SWIGTYPE {
-  $input = SWIG_NewPointerObj(%as_voidptr(new $1_ltype((const $1_ltype &)$1)), $&descriptor, SWIG_POINTER_OWN | %newpointer_flags);
+  $input = SWIG_NewPointerObj(%as_voidptr(new $1_ltype(SWIG_STD_MOVE($1))), $&descriptor, SWIG_POINTER_OWN | %newpointer_flags);
 }
 
 %typemap(directorin,noblock=1) SWIGTYPE * {