R-1.7.0: Rproxy.dll loadlibrary/freelibrary error (PR#2914)

Venkatesh:

I was hoping someone else would pick up on this one.  I don't know the
rproxy code at all, so I can't tell if the error you are seeing is
some new error in R or a mistake on your part.  I've cc'd this to
Thomas Baier; Thomas, can you comment on this?

Venkatesh, you do mention a "huge leakage difference".  Could you
expand on that, and maybe give a loop in plain R code that causes R to
grow without bounds?

Duncan Murdoch

On Mon, 5 May 2003 01:07:30 +0200 (MET DST), you wrote in message
<200305042307.h44N7U2b006301@pubhealth.ku.dk>:

Full_Name: Venkatesh Mysore
Version: R-1.7.0
OS: WindowsXP
Submission from: (NULL) (216.165.110.10)


While accessing Rproxy.dll repeatedly (using the code from the (D)COM example in
the R website) causes a failure in the 24th iteration. R-1.6.2 does NOT give
this error. This seems to be a memory management error, that might be linked to
the huge leakage difference between R-1.7.0 and R-1.6.2 (leakage observed using
Windows Task Manager).

Here is a C program that can be used to reproduce the error:
(the files SC-Proxy.h, Defn.h, Rinternals.h etc.. are to be included in the path
- see StatConnector.cpp in the (D)COM server example)


#include "windows.h"
#include "stdio.h"
#include "SC_Proxy.h"
#define RDLL "Rproxy.dll"
struct _SC_Proxy_Object* m_ProxyObject;
HMODULE m_ProxyModule;


#define SERVER_MAJOR_VERSION  "1"
#define SERVER_MINOR_VERSION "2"

#define	SCN_IERR_INTERFACENOTFOUND      0x81000000
#define	SCN_IERR_LIBRARYNOTFOUND        0x81000001
#define	SCN_IERR_INVALIDLIBRARY         0x81000002
#define	SCN_IERR_INITIALIZATIONFAILED   0x81000003
#define	SCN_IERR_INVALIDCONNECTORNAME   0x81000004
#define SCN_ERR_INITIALIZED             0x81000005
#define SCN_ERR_NOTINITIALIZED          0x81000006

#define TRACEBUFSIZE 1024
// 00-02-18 | baier | support arguments for connector initialization
// 01-04-04 | baier | enhancements by BDR: set RHOME from registry
// 03-04-07 | baier | check registry key on failure even if R_HOME is set,
//                    check PATH if everything else fails. trace failures!
int loadDll()
{
  static char lTraceBuffer[TRACEBUFSIZE];
    // get entry-point
if (getenv ("R_HOME"))
  { // BDR
	  OutputDebugString("from env:");
	  char DLLlocation[MAX_PATH];
	  strcpy(DLLlocation, getenv("R_HOME"));
	  strcat(DLLlocation, "\\bin\\");
	  strcat(DLLlocation, RDLL);
	  OutputDebugString(DLLlocation);
	  m_ProxyModule = LoadLibraryEx (DLLlocation, NULL, 
				 LOAD_WITH_ALTERED_SEARCH_PATH);
	  // trace failure!
	  if (m_ProxyModule == 0) {
		  sprintf(lTraceBuffer,"R_HOME set to \"%s\", failed to load \"%s\"\n",
			  getenv("R_HOME"),DLLlocation);
		  OutputDebugString(lTraceBuffer);
	  }
  }

     if (m_ProxyModule == 0)
  {
  // look in the registry
  OutputDebugString("from reg:");
  char DLLlocation[MAX_PATH];
  LONG rc;
  HKEY hkey;
  DWORD keytype = REG_SZ;
  DWORD cbData = sizeof (DLLlocation);
  rc = RegOpenKeyEx (HKEY_LOCAL_MACHINE, "Software\\R-core\\R", 0, 
		     KEY_READ, &hkey);
  if (rc == ERROR_SUCCESS)
    {
      rc = RegQueryValueEx (hkey, "InstallPath", 0, &keytype, 
			    (LPBYTE)DLLlocation, &cbData);
      RegCloseKey (hkey);
    }

  if (rc == ERROR_SUCCESS)
    {
      // set R_HOME
      char *buf;
      buf =
	(char *) malloc ((strlen (DLLlocation) + 8) * sizeof (char));
      strcpy (buf, "R_HOME=");
      strcat (buf, DLLlocation);
      putenv (buf);
      //SetEnvironmentVariable ("R_HOME",DLLlocation);
      strcat (DLLlocation, "\\bin\\");
	  strcat (DLLlocation, RDLL);
	  OutputDebugString(DLLlocation);
      m_ProxyModule = LoadLibraryEx (DLLlocation, NULL, 
				     LOAD_WITH_ALTERED_SEARCH_PATH);
      if (m_ProxyModule == 0) {
	sprintf(lTraceBuffer,"Registry information said to load \"%s\", failed!\n",
	        DLLlocation);
	OutputDebugString(lTraceBuffer);
      }
    }
  } //module==0

//m_ProxyModule = LoadLibraryEx ("C:\\R\\rw1070\\bin\\Rproxy.dll", NULL, 
//				 LOAD_WITH_ALTERED_SEARCH_PATH);



     SC_PROXY_GET_OBJECT lFunc;
     
     lFunc = (SC_PROXY_GET_OBJECT) GetProcAddress (m_ProxyModule,
   						   SC_PROXY_GET_OBJECT_FUN);
  
     
     if (lFunc == 0)
   	{
         return -1;
   	}
     
     // get proxy object
     ULONG lRc = lFunc (&m_ProxyObject,SC_PROXY_INTERFACE_VERSION);
     
  
     if ((lRc != SC_PROXY_OK) || (m_ProxyObject == 0))
   	{
   	  FreeLibrary (m_ProxyModule);
   	  m_ProxyModule = 0;
   	  
         return -2;
   	}
     
     char* lParams = 0;

lParams = strdup ("");
OutputDebugString("vtbl->init getting called:");         
     // init R
     lRc = m_ProxyObject->vtbl->init (m_ProxyObject,lParams);
OutputDebugString("done init.");      
     free (lParams);

     if (lRc != SC_PROXY_OK)
   	{
   	  m_ProxyObject->vtbl->release (m_ProxyObject);
   	  m_ProxyObject = 0;
   	  FreeLibrary (m_ProxyModule);
   	  m_ProxyModule = 0;
   	  
   	  return -3;
   	}
   return 1;
}

int unloadDll()
{

     m_ProxyObject->vtbl->release (m_ProxyObject);
  m_ProxyObject = 0;

  DWORD err;
     int b = FreeLibrary (m_ProxyModule);
  if (b==0) {
	  err = GetLastError();
	char ss[100];
	sprintf(ss,"\n\nErr = %d\n\n", err);
	OutputDebugString(ss);
	return -1;
  } else OutputDebugString("no error unloading Rproxy dll.\n\n");

  m_ProxyModule = 0;
   
 return 1;
}


int main() {
char ss[100];
int i,x,a;
for (i=1; i<=100; i++) {
	sprintf(ss,"Iteration: %d", i);
	OutputDebugString(ss);
x=loadDll();
if (x<=0) OutputDebugString("LoadLibraryEx ERROR.");
else OutputDebugString("LoadLibraryEx succeeded.");
a = unloadDll();
if (a<=0) OutputDebugString("FreeLibrary ERROR.");
else OutputDebugString("FreeLibrary succeeded.");
}
}

-----------------------------------------

-Venkatesh Mysore
Bioinformatics Group,
New York University