According to Howard Chu <hyc@highlandsun.com>:

According to Howard Chu <hyc@highlandsun.com>:
Applications should assume that the native dlopen is NOT
thread-safe, and take care of locking themselves. All application
calls into libltdl should thus be protected by the caller.

* libltdl/lt_mutex.c, libltdl/lt_mutex.h: Removed.
* libltdl/Makefile.am (pkginclude_HEADERS): Removed lt_mutex.h.
(libltdl_la_SOURCES): Removed lt_mutex.c and lt_mutex.h.
* libltdl/ltdl.h: Don't include lt_mutex.h.
* libltdl/lt__private.h (LT__MUTEX_GETERROR, LT__MUTEX_SETERROR)
(LT__MUTEX_SETERRORSTR): Renamed to...
(LT__GETERROR, LT__SETERROR, LT__SETERRORSTR): ...this.  Changed
all callers.
(LT__MUTEX_LOCK, LT__MUTEX_UNLOCK, lt_dlmutex_lock)
(lt_dlmutex_unlock, lt_dlmutex_seterror, lt_dlmutex_geterror):
Removed.  Changed all callers.
* doc/libtool.texi (Thread Saftey in libltdl):
* NEWS: Updated.