[Python-bugs-list] [ python-Bugs-444797 ] dlopen fails loading shared lib modules

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Bugs item #444797, was opened at 2001-07-26 06:57
You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=444797&group_id=5470

Category: Extension Modules
Group: Platform-specific
Status: Open
Resolution: None
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: dlopen fails loading shared lib modules

Initial Comment:
If the python interpreter is embedded in (built as) a
shared library that can be dynamically loaded by an
application, python shared library modules can not
be imported on Solaris and IRIX.

This works on HP-UX, AIX, and NT.

I have implemented a fix in the attached file 'dynload_shlib.c'
(from python 2.0).

IRIX requires the additional RTLD_GLOBAL 'mode' flag to
be passed to the dlopen calls.

Solaris requires the additional RTLD_GLOBAL and
RTLD_PARENT 'mode' flags to be passed to the dlopen
calls (the RTLD_GROUP and RTLD_WORLD flags were OR'd in
to preserve the defaults).

Please integrate this fix into future versions of python.  I can
provide more detailed information about the problem if necessary.


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Comment By: Dave Smith (dts)
Date: 2001-07-26 10:10

Message:
Logged In: YES 
user_id=281856

I don't see any way to attach a file to an existing bug#,
so i've just cut/pasted the file below.

--- BEGIN dynload_shlib.c ---

/* Support for dynamic loading of extension modules */

#include "Python.h"
#include "importdl.h"

#include <sys/types.h>
#include <sys/stat.h>
#if defined(__NetBSD__) && (NetBSD < 199712)
#include <nlist.h>
#include <link.h>
#define dlerror() "error in dynamic linking"
#else
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#endif

#ifndef RTLD_LAZY
#define RTLD_LAZY 1
#endif


const struct filedescr _PyImport_DynLoadFiletab[] = {
#ifdef __CYGWIN__
   {".pyd", "rb", C_EXTENSION},
   {".dll", "rb", C_EXTENSION},
#else
   {".so", "rb", C_EXTENSION},
   {"module.so", "rb", C_EXTENSION},
#endif
   {0, 0}
};

static struct {
   dev_t dev;
   ino_t ino;
   void *handle;
} handles[128];
static int nhandles = 0;


dl_funcptr _PyImport_GetDynLoadFunc(const char *fqname, const char *shortname,
                const char *pathname, FILE *fp)
{
   dl_funcptr p;
   void *handle;
   char funcname[258];
   char pathbuf[260];
        int mode;

   if (strchr(pathname, '/') == NULL) {
      /* Prefix bare filename with "./" */
      sprintf(pathbuf, "./%-.255s", pathname);
      pathname = pathbuf;
   }

   /* ### should there be a leading underscore for some platforms? */
   sprintf(funcname, "init%.200s", shortname);

   if (fp != NULL) {
      int i;
      struct stat statb;
      fstat(fileno(fp), &statb);
      for (i = 0; i < nhandles; i++) {
         if (statb.st_dev == handles[i].dev &&
             statb.st_ino == handles[i].ino) {
            p = (dl_funcptr) dlsym(handles[i].handle,
                         funcname);
            return p;
         }
      }
      if (nhandles < 128) {
         handles[nhandles].dev = statb.st_dev;
         handles[nhandles].ino = statb.st_ino;
      }
   }

        mode = RTLD_GLOBAL;
#ifdef RTLD_GROUP
        mode |= RTLD_GROUP;
#endif
#ifdef RTLD_PARENT
        mode |= RTLD_PARENT;
#endif
#ifdef RTLD_WORLD
        mode |= RTLD_WORLD;
#endif

#ifdef RTLD_NOW
   /* RTLD_NOW: resolve externals now
      (i.e. core dump now if some are missing) */
   if (Py_VerboseFlag)
      printf("dlopen(\%s\, %d);\n", pathname,
             RTLD_NOW | mode);
   handle = dlopen(pathname, RTLD_NOW | mode);
#else
   if (Py_VerboseFlag)
      printf("dlopen(\%s\, %d);\n", pathname,
             RTLD_LAZY | mode);
   handle = dlopen(pathname, RTLD_LAZY | mode);
#endif /* RTLD_NOW */
   if (handle == NULL) {
      PyErr_SetString(PyExc_ImportError, dlerror());
      return NULL;
   }
   if (fp != NULL && nhandles < 128)
      handles[nhandles++].handle = handle;
   p = (dl_funcptr) dlsym(handle, funcname);
   return p;
}
--- END dynload_shlib.c ---

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

Comment By: Guido van Rossum (gvanrossum)
Date: 2001-07-26 07:52

Message:
Logged In: YES 
user_id=6380

Sorry, your attachment didn't come through.

When you wish to attach a file to a tracker item you must
check
the checkbox before submitting changes. 

Please try again and check to make sure that it worked.

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

You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=105470&aid=444797&group_id=5470