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// DLL.cpp
// $Id$
#include "ace/DLL.h"
#include "ace/ACE.h"
ACE_RCSID(ace, DLL, "$Id$")
// Default constructor. Also, by default, the object will be closed
// before it is destroyed.
ACE_DLL::ACE_DLL (int close_on_destruction)
: handle_ (ACE_SHLIB_INVALID_HANDLE),
close_on_destruction_ (close_on_destruction)
{
}
// If the library name and the opening mode are specified than on
// object creation the library is implicitly opened.
ACE_DLL::ACE_DLL (const ACE_TCHAR *dll_name,
int open_mode,
int close_on_destruction)
: handle_ (ACE_OS::dlopen (dll_name,
open_mode)),
close_on_destruction_ (close_on_destruction)
{
if (this->handle_ == ACE_SHLIB_INVALID_HANDLE)
ACE_ERROR ((LM_ERROR,
ACE_TEXT ("%s\n"),
this->error ()));
}
// The library is closed before the class gets destroyed depending on
// the close_on_destruction value specified which is stored in
// close_on_destruction_.
ACE_DLL::~ACE_DLL (void)
{
// CLose the library only if it hasn't been already.
this->close ();
}
// This method opens the library based on the mode specified using the
// ACE_SHLIB_HANDLE which is obtained on making the ACE_OS::dlopen call.
// The default mode is:
// RTLD_LAZY Only references to data symbols are relocate when the
// object is first loaded.
// The other modes include:
// RTLD_NOW All necessary relocations are performed when the
// object is first loaded.
// RTLD_GLOBAL The object symbols are made available for the
// relocation processing of any other object.
int
ACE_DLL::open (const ACE_TCHAR *dll_filename,
int open_mode,
int close_on_destruction)
{
// This check is necessary as the library could be opened more than
// once without closing it which would cause handle memory leaks.
this->close ();
// Reset the flag
this->close_on_destruction_ = close_on_destruction;
// Find out where the library is
ACE_TCHAR dll_pathname[MAXPATHLEN + 1];
// Transform the pathname into the appropriate dynamic link library
// by searching the ACE_LD_SEARCH_PATH.
int result = ACE::ldfind (dll_filename,
dll_pathname,
(sizeof dll_pathname / sizeof (ACE_TCHAR)));
// Check for errors
if (result != 0)
return result;
// The ACE_SHLIB_HANDLE object is obtained.
this->handle_ = ACE_OS::dlopen (dll_pathname,
open_mode);
if (this->handle_ == ACE_SHLIB_INVALID_HANDLE)
ACE_ERROR_RETURN ((LM_ERROR,
ACE_TEXT ("%s\n"), this->error ()),
-1);
return 0;
}
// The symbol refernce of the name specified is obtained.
void *
ACE_DLL::symbol (const ACE_TCHAR *sym_name)
{
return ACE_OS::dlsym (this->handle_, sym_name);
}
// The library is closed using the ACE_SHLIB_HANDLE obejct. i.e. The
// shared object is now disassociated form the current process.
int
ACE_DLL::close (void)
{
int retval = 0;
// The handle is checked to see whether the library is closed
// already and the <close_on_destruction_> flag is specified. If
// not, it is closed and the handle is made invalid to indicate that
// it's now closed.
if (this->close_on_destruction_ != 0 &&
this->handle_ != ACE_SHLIB_INVALID_HANDLE)
{
retval = ACE_OS::dlclose (this->handle_);
}
this->handle_ = ACE_SHLIB_INVALID_HANDLE;
return retval;
}
// This method is used on error in an library operation.
ACE_TCHAR *
ACE_DLL::error (void)
{
return ACE_OS::dlerror ();
}
// Return the handle to the user either temporarily or forever, thus
// orphaning it. If 0 means the user wants the handle forever and if 1
// means the user temporarily wants to take the handle.
ACE_SHLIB_HANDLE
ACE_DLL::get_handle (int become_owner)
{
// Since the caller is becoming the owner of the handle we lose
// rights to close it on destruction. The new controller has to do
// it explicitly.
if (become_owner)
this->close_on_destruction_ = 0;
// Return the handle requested by the user.
return this->handle_;
}
// Set the handle for the DLL. By default, the object will be closed
// before it is destroyed.
int
ACE_DLL::set_handle (ACE_SHLIB_HANDLE handle,
int close_on_destruction)
{
// Close the handle in use before accepting the next one.
if (this->close () == -1)
ACE_ERROR_RETURN ((LM_ERROR,
ACE_TEXT ("%s\n"), this->error ()),
-1);
this->handle_ = handle;
this->close_on_destruction_ = close_on_destruction;
return 0;
}
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