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/*
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 1997 by Silicon Graphics. All rights reserved.
* Copyright (c) 2000 by Hewlett-Packard Company. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*
* Original author: Bill Janssen
* Heavily modified by Hans Boehm and others
*/
#include "private/gc_priv.h"
/*
* This used to be in dyn_load.c. It was extracted into a separate file
* to avoid having to link against libdl.{a,so} if the client doesn't call
* dlopen. Of course this fails if the collector is in a dynamic
* library. -HB
*/
# if defined(GC_PTHREADS) && !defined(GC_DARWIN_THREADS) \
&& !defined(GC_WIN32_PTHREADS)
# undef GC_MUST_RESTORE_REDEFINED_DLOPEN
# if defined(dlopen) && !defined(GC_USE_LD_WRAP)
/* To support various threads pkgs, gc.h interposes on dlopen by */
/* defining "dlopen" to be "GC_dlopen", which is implemented below. */
/* However, both GC_FirstDLOpenedLinkMap() and GC_dlopen() use the */
/* real system dlopen() in their implementation. We first remove */
/* gc.h's dlopen definition and restore it later, after GC_dlopen(). */
# undef dlopen
# define GC_MUST_RESTORE_REDEFINED_DLOPEN
# endif
/* Make sure we're not in the middle of a collection, and make */
/* sure we don't start any. Returns previous value of GC_dont_gc. */
/* This is invoked prior to a dlopen call to avoid synchronization */
/* issues. We can't just acquire the allocation lock, since startup */
/* code in dlopen may try to allocate. */
/* This solution risks heap growth in the presence of many dlopen */
/* calls in either a multithreaded environment, or if the library */
/* initialization code allocates substantial amounts of GC'ed memory. */
/* But I don't know of a better solution. */
static void disable_gc_for_dlopen(void)
{
LOCK();
while (GC_incremental && GC_collection_in_progress()) {
GC_collect_a_little_inner(1000);
}
++GC_dont_gc;
UNLOCK();
}
/* Redefine dlopen to guarantee mutual exclusion with */
/* GC_register_dynamic_libraries. */
/* Should probably happen for other operating systems, too. */
#include <dlfcn.h>
/* This is similar to WRAP/REAL_FUNC() in pthread_support.c. */
#ifdef GC_USE_LD_WRAP
# define WRAP_DLFUNC(f) __wrap_##f
# define REAL_DLFUNC(f) __real_##f
#else
# define WRAP_DLFUNC(f) GC_##f
# define REAL_DLFUNC(f) f
#endif
GC_API void * WRAP_DLFUNC(dlopen)(const char *path, int mode)
{
void * result;
# ifndef USE_PROC_FOR_LIBRARIES
disable_gc_for_dlopen();
# endif
result = (void *)REAL_DLFUNC(dlopen)(path, mode);
# ifndef USE_PROC_FOR_LIBRARIES
GC_enable(); /* undoes disable_gc_for_dlopen */
# endif
return(result);
}
#ifdef GC_USE_LD_WRAP
/* Define GC_ function as an alias for the plain one, which will be */
/* intercepted. This allows files which include gc.h, and hence */
/* generate references to the GC_ symbol, to see the right symbol. */
GC_API int GC_dlopen(const char *path, int mode)
{
return dlopen(path, mode);
}
#endif /* Linker-based interception. */
# ifdef GC_MUST_RESTORE_REDEFINED_DLOPEN
# define dlopen GC_dlopen
# endif
#endif /* GC_PTHREADS */
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