Interchanging data with zend (multidimensional arrays)

I'm embeding PHP in my app (writen in Delphi 2010), using PHP4Delphi component to interface with php5ts.dll. I guess my program acts as extension for the PHP (sapi module?) as it registers some functions and constants which can be used in PHP scripts... anyway, works well when using simple data types, but when I try to use multidimensional array as return value I get error

Access violation at address 01CD3C35 in module 'php5ts.dll'. Read of address 0231E608.

Stack list

(000A2C35){php5ts.dll} [01CD3C35] destroy_op_array + $35

(004C4D61){myApp.exe } [008C5D61] php4delphi.TPHPEngine.ShutdownEngine (Line 1497, "php4delphi.pas" + 17) + $7

The line 1497 in php4delphi.pas is call to tsrm_shutdown();

To me it looks like garbage collector crashing at the end of the script, so I'm suspecting I do not send data correctly back to the engine... thus my question is how one is supposed to send multidimensional arrays back to PHP?

The pattern I'm using is

var subArray: pzval;  
_array_init(return_value, nil, 0);  
for x := 0 to Data.Count-1 do begin  
   subArray := MAKE_STD_ZVAL;  
   _array_init(subArray, nil, 0);  
   // populate subarray with data, including other subarrays
   ...
   // add subarray to the main array
   add_index_zval(return_value, x, subArray);
end;

Do I have to somewhere "register" the subarrays I create? Do I have to increase or decrease refcount or set is_ref? IOW, how must the return_value and zvals of the subarrays to be set up?

I experimented with adding 1 to e开发者_JAVA百科ach array's refcount (althought MAKE_STD_ZVAL already initializes refcount to 1) and that cures the AV but then sometimes app just disappears when executing the script - I suspect it causes infinite recursion in engine's memeory manager, crashing the php DLL and taking the app with it... When seting refcount to 0 (zero; assuming that when return value is assigned in the PHP script it's refcount will be 1 and then when the PHP variable goes out of scope it will be destroyed) all seems to work (ie no crash, no AV) but the script wont generate any output, just empty html file...

I also send data as arrays into my function, then use zend_hash_find, zend_hash_get_current_data etc to read the data. Could this mess up the refcounts of the variables? Ie do I have to decrease refcout of the variable returned by zend_hash_find when I'm done with it?

And is it safe to reuse same variable when iterating over an array, ie

var Val: pppzval;
new(Val);
zend_hash_internal_pointer_reset(aZendArr^.value.ht);
for x := 1 to zend_hash_num_elements(aZendArr^.value.ht) do begin
   zend_hash_get_current_data(aZendArr^.value.ht, Val);
   // read data from Val to local variable and do something with it
   zend_hash_move_forward_ex(aZendArr^.value.ht, nil);
end;
Dispose(Val);

or should each iteration of the loop create / free Val?

TIA

ain

---

here is my work arround:

function InitSubArray(TSRMLS_DC : pointer):pzval;
begin
  Result := MAKE_STD_ZVAL;
  Result^.refcount:=2;
  Result^._type:=IS_ARRAY;
  InitPHPArray(Result,TSRMLS_DC);
end;

Set the refcount to 2 solve the problem for me, I don't know why, just tried many times, and found this.

---

As your question quite long I will split my answer in few parts.

1. PHP4Delphi component acts as SAPI module. The ISAPI SAPI module was used as a prototype for it
2. What version of PHP4Delphi are you using? In my copy the call to tsrm_shutdown(); is located on line 1509, not 1497
3. I would propose to read the array in the following way:

procedure TForm1.ExecuteGetArray(Sender: TObject;
  Parameters: TFunctionParams; var ReturnValue: Variant;
  ZendVar: TZendVariable; TSRMLS_DC: Pointer);
var
  ht  : PHashTable;
  data: ^ppzval;
  cnt : integer;
  variable : pzval;
  tmp : ^ppzval;
begin
  ht := GetSymbolsTable;
  if Assigned(ht) then
   begin
      new(data);
       if zend_hash_find(ht, 'ar', 3, data) = SUCCESS then
          begin
            variable := data^^;
            if variable^._type = IS_ARRAY then
             begin
               SetLength(ar, zend_hash_num_elements(variable^.value.ht));
               for cnt := 0 to zend_hash_num_elements(variable^.value.ht) -1  do
                begin
                  new(tmp);
                  zend_hash_index_find(variable^.value.ht, cnt, tmp);
                  ar[cnt] := tmp^^^.value.str.val;
                  freemem(tmp);
                end;
             end;
          end;
       freemem(data);
   end;
end;

1. Some people reported about the problems with integer indexes for arrays. I would propose to change the index to string:

procedure TPHPExtension1.PHPExtension1Functions1Execute(Sender: TObject;
  Parameters: TFunctionParams; var ReturnValue: Variant; ZendVar : TZendVariable;
  TSRMLS_DC: Pointer);
var
  pval : pzval;
  cnt  : integer;
  months : pzval;
  smonths : pzval;
begin
 pval := ZendVar.AsZendVariable;
 if _array_init(pval, nil, 0) = FAILURE then
  begin
    php_error_docref(nil , TSRMLS_DC, E_ERROR, 'Unable to initialize array');
    ZVAL_FALSE(pval);
    Exit;
  end;

  months := MAKE_STD_ZVAL;
  smonths := MAKE_STD_ZVAL;

  _array_init(months, nil, 0);
  _array_init(smonths, nil, 0);

  for cnt := 1 to 12 do
   begin
     add_next_index_string(months, PChar(LongMonthNames[cnt]), 1);
     add_next_index_string(smonths, PChar(ShortMonthNames[cnt]), 1);
   end;

  add_assoc_zval_ex(pval, 'months', strlen('months') + 1, months);
  add_assoc_zval_ex(pval, 'abbrevmonths', strlen('abbrevmonths') + 1, smonths);

end;

1. The error in tsrm_shutdown is usually related to the memory management and Delphi strings. php5ts.dll has built-in memory manager and it works independent from the Delphi memory manager. When the string reference is equal to zero from the Delphi point of view it can be deallocated, but at the same time it can be still in use by the PHP engine. If you populate your subarrays with strings make sure the strings are not collected by the Delphi memory manager. For example you can convert the strings to PAnsiChar before adding it to the array

{$IFNDEF COMPILER_VC9}
fnc^.internal_function.function_name := strdup(method_name);
{$ELSE}
fnc^.internal_function.function_name := DupStr(method_name);
{$ENDIF}