-(defstruct shared-object file sap)
-
-(defun dlopen-or-lose (filename)
- (dlerror) ; clear old errors
- (let ((sap (dlopen filename (logior rtld-global rtld-now))))
- (when (zerop (sap-int sap))
- (error "Could not open ~:[runtime~;~:*shared object ~S~]: ~A"
- filename (dlerror)))
- sap))
-
-(defun load-shared-object (file)
- "Load a shared library/dynamic shared object file/general
-dlopenable alien container, such as a .so on an ELF platform.
-
-References to foreign symbols in loaded shared objects do not survive
-intact through SB-EXT:SAVE-LISP-AND die on all platforms. See
-SB-EXT:SAVE-LISP-AND-DIE for details."
- (let* ((real-file (or (unix-namestring file) file))
- (sap (dlopen-or-lose real-file))
- (obj (make-shared-object :file real-file :sap sap)))
- (unless (member sap *shared-objects*
- :test #'sap= :key #'shared-object-sap)
- (setf *shared-objects* (append *shared-objects* (list obj))))
- (pathname real-file)))
+(defstruct shared-object pathname namestring handle dont-save)
+
+(defun load-shared-object (pathname &key dont-save)
+ #!+sb-doc
+ "Load a shared library / dynamic shared object file / similar foreign
+container specified by designated PATHNAME, such as a .so on an ELF platform.
+
+Locating the shared object follows standard rules of the platform, consult the
+manual page for dlopen(3) for details. Typically paths speficied by
+environment variables such as LD_LIBRARY_PATH are searched if the PATHNAME has
+no directory, but on some systems (eg. Mac OS X) search may happen even if
+PATHNAME is absolute. (On Windows LoadLibrary is used instead of dlopen(3).)
+
+On non-Windows platoforms calling LOAD-SHARED-OBJECT again with an PATHNAME
+EQUAL to the designated pathname of a previous call will replace the old
+definitions; if a symbol was previously referenced thru the object and is not
+present in the reloaded version an error will be signalled. Reloading may not
+work as expected if user or library-code has called dlopen(3) on the same
+shared object.
+
+LOAD-SHARED-OBJECT interacts with SB-EXT:SAVE-LISP-AND-DIE:
+
+1. If DONT-SAVE is true (default is NIL), the shared object will be dropped
+when SAVE-LISP-AND-DIE is called -- otherwise shared objects are reloaded
+automatically when a saved core starts up. Specifying DONT-SAVE can be useful
+when the location of the shared object on startup is uncertain.
+
+2. On most platforms references in compiled code to foreign symbols in shared
+objects (such as those generated by DEFINE-ALIEN-ROUTINE) remain valid across
+SAVE-LISP-AND-DIE. On those platforms where this is not supported, a WARNING
+will be signalled when the core is saved -- this is orthogonal from DONT-SAVE."
+ (let ((pathname (pathname pathname)))
+ (sb!thread:with-mutex (*shared-objects-lock*)
+ (let* ((old (find pathname *shared-objects*
+ :key #'shared-object-pathname
+ :test #'equal))
+ (obj (or old (make-shared-object
+ :pathname pathname
+ :namestring (native-namestring
+ (translate-logical-pathname pathname)
+ :as-file t)))))
+ (setf (shared-object-dont-save obj) dont-save)
+ ;; FIXME: Why doesn's dlopen-or-lose on already loaded stuff work on
+ ;; Windows?
+ #!-win32
+ (dlopen-or-lose obj)
+ #!+win32
+ (unless old
+ (dlopen-or-lose obj))
+ (setf *shared-objects* (append (remove obj *shared-objects*)
+ (list obj)))
+ ;; FIXME: Why doesn't the linkage table work on Windows? (Or maybe it
+ ;; does and this can be just #!+linkage-table?) Note: remember to change
+ ;; FOREIGN-DEINIT as well then!
+ #!+(and linkage-table (not win32))
+ (when (or old (undefined-foreign-symbols-p))
+ (update-linkage-table))))
+ pathname))
+
+(defun unload-shared-object (pathname)
+ #!+sb-doc
+ "Unloads the shared object loaded earlier using the designated PATHNAME with
+LOAD-SHARED-OBJECT, to the degree supported on the platform.
+
+Experimental."
+ (let ((pathname (pathname pathname)))
+ (sb!thread:with-mutex (*shared-objects-lock*)
+ (let ((old (find pathname *shared-objects*
+ :key #'shared-object-pathname
+ :test #'equal)))
+ (when old
+ #!-hpux (dlclose-or-lose old)
+ (setf *shared-objects* (remove old *shared-objects*))
+ #!+(and linkage-table (not win32))
+ (update-linkage-table))))))