\f
;;;; utilities
-(eval-when (:compile-toplevel :load-toplevel :execute)
- (defconstant max-hash sb!xc:most-positive-fixnum))
-
-(deftype hash ()
- `(integer 0 ,max-hash))
-
-;;; FIXME: Does this always make a nonnegative FIXNUM? If so, then
-;;; explain why. If not (or if the reason it always makes a
-;;; nonnegative FIXNUM is only the accident that pointers in supported
-;;; architectures happen to be in the lower half of the address
-;;; space), then fix it.
-#!-sb-fluid (declaim (inline pointer-hash))
-(defun pointer-hash (key)
- (declare (values hash))
- (truly-the hash (%primitive sb!c:make-fixnum key)))
+;;; Code for detecting concurrent accesses to the same table from
+;;; multiple threads. Only compiled in when the :SB-HASH-TABLE-DEBUG
+;;; feature is enabled. The main reason for the existence of this code
+;;; is to detect thread-unsafe uses of hash-tables in sbcl itself,
+;;; where debugging anythign can be impossible after an important
+;;; internal hash-table has been corrupted. It's plausible that this
+;;; could be useful for some user code too, but the runtime cost is
+;;; really too high to enable it by default.
+(defmacro with-concurrent-access-check (hash-table operation &body body)
+ (declare (ignorable hash-table operation)
+ (type (member :read :write) operation))
+ #!-sb-hash-table-debug
+ `(progn ,@body)
+ #!+sb-hash-table-debug
+ (let ((thread-slot-accessor (if (eq operation :read)
+ 'hash-table-reading-thread
+ 'hash-table-writing-thread)))
+ (once-only ((hash-table hash-table))
+ `(progn
+ (flet ((body-fun ()
+ ,@body)
+ (error-fun ()
+ ;; Don't signal more errors for this table.
+ (setf (hash-table-signal-concurrent-access ,hash-table) nil)
+ (cerror "Ignore the concurrent access"
+ "Concurrent access to ~A" ,hash-table)))
+ (declare (inline body-fun))
+ (if (hash-table-signal-concurrent-access ,hash-table)
+ (unwind-protect
+ (progn
+ (unless (and (null (hash-table-writing-thread
+ ,hash-table))
+ ,@(when (eq operation :write)
+ `((null (hash-table-reading-thread
+ ,hash-table)))))
+ (error-fun))
+ (setf (,thread-slot-accessor ,hash-table)
+ sb!thread::*current-thread*)
+ (body-fun))
+ (unless (and ,@(when (eq operation :read)
+ `((null (hash-table-writing-thread
+ ,hash-table))))
+ ,@(when (eq operation :write)
+ ;; no readers are allowed while writing
+ `((null (hash-table-reading-thread
+ ,hash-table))
+ (eq (hash-table-writing-thread
+ ,hash-table)
+ sb!thread::*current-thread*))))
+ (error-fun))
+ (when (eq (,thread-slot-accessor ,hash-table)
+ sb!thread::*current-thread*)
+ ;; this is not 100% correct here and may hide
+ ;; concurrent access in rare circumstances.
+ (setf (,thread-slot-accessor ,hash-table) nil)))
+ (body-fun)))))))
#!-sb-fluid (declaim (inline eq-hash))
(defun eq-hash (key)
(declare (values hash (member t nil)))
(values (pointer-hash key)
- (oddp (get-lisp-obj-address key))))
+ (oddp (get-lisp-obj-address key))))
#!-sb-fluid (declaim (inline equal-hash))
(defun equal-hash (key)
(declare (values hash (member t nil)))
- (values (sxhash key) nil))
+ (typecase key
+ ;; For some types the definition of EQUAL implies a special hash
+ ((or string cons number bit-vector pathname)
+ (values (sxhash key) nil))
+ ;; Otherwise use an EQ hash, rather than SXHASH, since the values
+ ;; of SXHASH will be extremely badly distributed due to the
+ ;; requirements of the spec fitting badly with our implementation
+ ;; strategy.
+ (t
+ (eq-hash key))))
#!-sb-fluid (declaim (inline eql-hash))
(defun eql-hash (key)
(defun equalp-hash (key)
(declare (values hash (member t nil)))
- (values (psxhash key) nil))
+ (typecase key
+ ;; Types requiring special treatment. Note that PATHNAME and
+ ;; HASH-TABLE are caught by the STRUCTURE-OBJECT test.
+ ((or array cons number character structure-object)
+ (values (psxhash key) nil))
+ (t
+ (eq-hash key))))
+
+(declaim (inline index-for-hashing))
+(defun index-for-hashing (hash length)
+ (declare (type hash hash length))
+ ;; We're using power of two tables which obviously are very
+ ;; sensitive to the exact values of the low bits in the hash
+ ;; value. Do a little shuffling of the value to mix the high bits in
+ ;; there too.
+ (truly-the index
+ (logand (1- length)
+ (+ (logxor #b11100101010001011010100111
+ hash)
+ (ash hash -3)
+ (ash hash -12)
+ (ash hash -20)))))
-(defun almost-primify (num)
- (declare (type index num))
- #!+sb-doc
- "Return an almost prime number greater than or equal to NUM."
- (if (= (rem num 2) 0)
- (setq num (+ 1 num)))
- (if (= (rem num 3) 0)
- (setq num (+ 2 num)))
- (if (= (rem num 7) 0)
- (setq num (+ 4 num)))
- num)
\f
;;;; user-defined hash table tests
-(defvar *hash-table-tests* nil)
+(defvar *user-hash-table-tests* nil)
-(defun define-hash-table-test (name test-fun hash-fun)
- #!+sb-doc
- "Define a new kind of hash table test."
- (declare (type symbol name)
- (type function test-fun hash-fun))
- (setf *hash-table-tests*
- (cons (list name test-fun hash-fun)
- (remove name *hash-table-tests* :test #'eq :key #'car)))
+(defun register-hash-table-test (name hash-fun)
+ (declare (symbol name) (function hash-fun))
+ (unless (fboundp name)
+ (error "Cannot register ~S has a hash table test: undefined function."
+ name))
+ (with-single-package-locked-error
+ (:symbol name "defining ~S as a hash table test")
+ (let* ((test-fun (fdefinition name))
+ (this (list name test-fun hash-fun))
+ (spec (assoc name *user-hash-table-tests*)))
+ (cond (spec
+ (unless (and (eq (second spec) test-fun)
+ (eq (third spec) hash-fun))
+ (style-warn "Redefining hash table test ~S." name)
+ (setf (cdr spec) (cdr this))))
+ (t
+ (push this *user-hash-table-tests*)))))
name)
+
+(defmacro define-hash-table-test (name hash-function)
+ #!+sb-doc
+ "Defines NAME as a new kind of hash table test for use with the :TEST
+argument to MAKE-HASH-TABLE, and associates a default HASH-FUNCTION with it.
+
+NAME must be a symbol naming a global two argument equivalence predicate.
+Afterwards both 'NAME and #'NAME can be used with :TEST argument. In both
+cases HASH-TABLE-TEST will return the symbol NAME.
+
+HASH-FUNCTION must be a symbol naming a global hash function consistent with
+the predicate, or be a LAMBDA form implementing one in the current lexical
+environment. The hash function must compute the same hash code for any two
+objects for which NAME returns true, and subsequent calls with already hashed
+objects must always return the same hash code.
+
+Note: The :HASH-FUNCTION keyword argument to MAKE-HASH-TABLE can be used to
+override the specified default hash-function.
+
+Attempting to define NAME in a locked package as hash-table test causes a
+package lock violation.
+
+Examples:
+
+ ;;; 1.
+
+ ;; We want to use objects of type FOO as keys (by their
+ ;; names.) EQUALP would work, but would make the names
+ ;; case-insensitive -- which we don't want.
+ (defstruct foo (name nil :type (or null string)))
+
+ ;; Define an equivalence test function and a hash function.
+ (defun foo-name= (f1 f2) (equal (foo-name f1) (foo-name f2)))
+ (defun sxhash-foo-name (f) (sxhash (foo-name f)))
+
+ (define-hash-table-test foo-name= sxhash-foo-name)
+
+ ;; #'foo-name would work too.
+ (defun make-foo-table () (make-hash-table :test 'foo-name=))
+
+ ;;; 2.
+
+ (defun == (x y) (= x y))
+
+ (define-hash-table-test ==
+ (lambda (x)
+ ;; Hash codes must be consistent with test, so
+ ;; not (SXHASH X), since
+ ;; (= 1 1.0) => T
+ ;; (= (SXHASH 1) (SXHASH 1.0)) => NIL
+ ;; Note: this doesn't deal with complex numbers or
+ ;; bignums too large to represent as double floats.
+ (sxhash (coerce x 'double-float))))
+
+ ;; #'== would work too
+ (defun make-number-table () (make-hash-table :test '==))
+"
+ (check-type name symbol)
+ (if (member name '(eq eql equal equalp))
+ (error "Cannot redefine standard hash table test ~S." name)
+ (cond ((symbolp hash-function)
+ `(register-hash-table-test ',name (symbol-function ',hash-function)))
+ ((and (consp hash-function) (eq 'lambda (car hash-function)))
+ `(register-hash-table-test ',name #',hash-function))
+ (t
+ (error "Malformed HASH-FUNCTION: ~S" hash-function)))))
\f
;;;; construction and simple accessors
(defconstant +min-hash-table-size+ 16)
+(defconstant +min-hash-table-rehash-threshold+ (float 1/16 1.0))
-(defun make-hash-table (&key (test 'eql)
- (size +min-hash-table-size+)
- (rehash-size 1.5)
- (rehash-threshold 1)
- (weak-p nil))
+(defun make-hash-table (&key
+ (test 'eql)
+ (size +min-hash-table-size+)
+ (rehash-size 1.5)
+ (rehash-threshold 1)
+ (hash-function nil)
+ (weakness nil)
+ (synchronized))
#!+sb-doc
"Create and return a new hash table. The keywords are as follows:
- :TEST -- Indicates what kind of test to use.
- :SIZE -- A hint as to how many elements will be put in this hash
- table.
- :REHASH-SIZE -- Indicates how to expand the table when it fills up.
- If an integer, add space for that many elements. If a floating
- point number (which must be greater than 1.0), multiply the size
- by that amount.
- :REHASH-THRESHOLD -- Indicates how dense the table can become before
- forcing a rehash. Can be any positive number <=1, with density
- approaching zero as the threshold approaches 0. Density 1 means an
- average of one entry per bucket.
- :WEAK-P -- (This is an extension from CMU CL, not currently supported
- in SBCL 0.6.6, but perhaps supported in a future version.) If T,
- don't keep entries if the key would otherwise be garbage."
+
+ :TEST
+ Determines how keys are compared. Must a designator for one of the
+ standard hash table tests, or a hash table test defined using
+ SB-EXT:DEFINE-HASH-TABLE-TEST. Additionally, when an explicit
+ HASH-FUNCTION is provided (see below), any two argument equivalence
+ predicate can be used as the TEST.
+
+ :SIZE
+ A hint as to how many elements will be put in this hash table.
+
+ :REHASH-SIZE
+ Indicates how to expand the table when it fills up. If an integer, add
+ space for that many elements. If a floating point number (which must be
+ greater than 1.0), multiply the size by that amount.
+
+ :REHASH-THRESHOLD
+ Indicates how dense the table can become before forcing a rehash. Can be
+ any positive number <=1, with density approaching zero as the threshold
+ approaches 0. Density 1 means an average of one entry per bucket.
+
+ :HASH-FUNCTION
+ If NIL (the default), a hash function based on the TEST argument is used,
+ which then must be one of the standardized hash table test functions, or
+ one for which a default hash function has been defined using
+ SB-EXT:DEFINE-HASH-TABLE-TEST. If HASH-FUNCTION is specified, the TEST
+ argument can be any two argument predicate consistent with it. The
+ HASH-FUNCTION is expected to return a non-negative fixnum hash code.
+
+ :WEAKNESS
+ When :WEAKNESS is not NIL, garbage collection may remove entries from the
+ hash table. The value of :WEAKNESS specifies how the presence of a key or
+ value in the hash table preserves their entries from garbage collection.
+
+ Valid values are:
+
+ :KEY means that the key of an entry must be live to guarantee that the
+ entry is preserved.
+
+ :VALUE means that the value of an entry must be live to guarantee that
+ the entry is preserved.
+
+ :KEY-AND-VALUE means that both the key and the value must be live to
+ guarantee that the entry is preserved.
+
+ :KEY-OR-VALUE means that either the key or the value must be live to
+ guarantee that the entry is preserved.
+
+ NIL (the default) means that entries are always preserved.
+
+ :SYNCHRONIZED
+ If NIL (the default), the hash-table may have multiple concurrent readers,
+ but results are undefined if a thread writes to the hash-table
+ concurrently with another reader or writer. If T, all concurrent accesses
+ are safe, but note that CLHS 3.6 (Traversal Rules and Side Effects)
+ remains in force. See also: SB-EXT:WITH-LOCKED-HASH-TABLE. This keyword
+ argument is experimental, and may change incompatibly or be removed in the
+ future."
(declare (type (or function symbol) test))
(declare (type unsigned-byte size))
- (when weak-p
- (error "stub: unsupported WEAK-P option"))
(multiple-value-bind (test test-fun hash-fun)
(cond ((or (eq test #'eq) (eq test 'eq))
- (values 'eq #'eq #'eq-hash))
- ((or (eq test #'eql) (eq test 'eql))
- (values 'eql #'eql #'eql-hash))
- ((or (eq test #'equal) (eq test 'equal))
- (values 'equal #'equal #'equal-hash))
- ((or (eq test #'equalp) (eq test 'equalp))
- (values 'equalp #'equalp #'equalp-hash))
- (t
- ;; FIXME: I'd like to remove *HASH-TABLE-TESTS* stuff.
- ;; Failing that, I'd like to rename it to
- ;; *USER-HASH-TABLE-TESTS*.
- (dolist (info *hash-table-tests*
- (error "unknown :TEST for MAKE-HASH-TABLE: ~S"
- test))
- (destructuring-bind (test-name test-fun hash-fun) info
- (when (or (eq test test-name) (eq test test-fun))
- (return (values test-name test-fun hash-fun)))))))
+ (values 'eq #'eq #'eq-hash))
+ ((or (eq test #'eql) (eq test 'eql))
+ (values 'eql #'eql #'eql-hash))
+ ((or (eq test #'equal) (eq test 'equal))
+ (values 'equal #'equal #'equal-hash))
+ ((or (eq test #'equalp) (eq test 'equalp))
+ (values 'equalp #'equalp #'equalp-hash))
+ (t
+ ;; FIXME: It would be nice to have a compiler-macro
+ ;; that resolved this at compile time: we could grab
+ ;; the alist cell in a LOAD-TIME-VALUE, etc.
+ (dolist (info *user-hash-table-tests*
+ (if hash-function
+ (if (functionp test)
+ (values (%fun-name test) test nil)
+ (values test (%coerce-callable-to-fun test) nil))
+ (error "Unknown :TEST for MAKE-HASH-TABLE: ~S"
+ test)))
+ (destructuring-bind (test-name test-fun hash-fun) info
+ (when (or (eq test test-name) (eq test test-fun))
+ (return (values test-name test-fun hash-fun)))))))
+ (when hash-function
+ (setf hash-fun
+ ;; Quickly check if the function has return return type which
+ ;; guarantees that the secondary return value is always NIL:
+ ;; (VALUES * &OPTIONAL), (VALUES * NULL ...) or (VALUES *
+ ;; &OPTIONAL NULL ...)
+ (let* ((actual (%coerce-callable-to-fun hash-function))
+ (type-spec (%fun-type actual))
+ (return-spec (when (consp type-spec)
+ (caddr type-spec)))
+ (extra-vals (when (consp return-spec)
+ (cddr return-spec))))
+ (if (and (consp extra-vals)
+ (or (eq 'null (car extra-vals))
+ (and (eq '&optional (car extra-vals))
+ (or (not (cdr extra-vals))
+ (eq 'null (cadr extra-vals))))))
+ actual
+ ;; If there is a potential secondary value, make sure we
+ ;; don't accidentally claim EQ based hashing...
+ (lambda (object)
+ (declare (optimize (safety 0) (speed 3)))
+ (values (funcall actual object) nil))))))
(let* ((size (max +min-hash-table-size+
- (min size
- ;; SIZE is just a hint, so if the user asks
- ;; for a SIZE which'd be too big for us to
- ;; easily implement, we bump it down.
- (floor array-dimension-limit 16))))
- (rehash-size (if (integerp rehash-size)
- rehash-size
- (float rehash-size 1.0)))
- ;; FIXME: Original REHASH-THRESHOLD default should be 1.0,
- ;; not 1, to make it easier for the compiler to avoid
- ;; boxing.
- (rehash-threshold (float rehash-threshold 1.0))
- (size+1 (1+ size)) ; The first element is not usable.
+ (min size
+ ;; SIZE is just a hint, so if the user asks
+ ;; for a SIZE which'd be too big for us to
+ ;; easily implement, we bump it down.
+ (floor array-dimension-limit 1024))))
+ (rehash-size (if (integerp rehash-size)
+ rehash-size
+ (float rehash-size 1.0)))
+ ;; FIXME: Original REHASH-THRESHOLD default should be 1.0,
+ ;; not 1, to make it easier for the compiler to avoid
+ ;; boxing.
+ (rehash-threshold (max +min-hash-table-rehash-threshold+
+ (float rehash-threshold 1.0)))
+ (size+1 (1+ size)) ; The first element is not usable.
;; KLUDGE: The most natural way of expressing the below is
;; (round (/ (float size+1) rehash-threshold)), and indeed
;; it was expressed like that until 0.7.0. However,
;; but only for truncating; therefore, we fudge this issue
;; a little. The other uses of truncate, below, similarly
;; used to be round. -- CSR, 2002-10-01
- ;;
- ;; Note that this has not yet been audited for
- ;; correctness. It just seems to work. -- CSR, 2002-11-02
- (scaled-size (truncate (/ (float size+1) rehash-threshold)))
- (length (almost-primify (max scaled-size
- (1+ +min-hash-table-size+))))
- (index-vector (make-array length
- :element-type '(unsigned-byte 32)
- :initial-element 0))
- ;; needs to be the same length as the KV vector
- (next-vector (make-array size+1
- :element-type '(unsigned-byte 32)))
- (kv-vector (make-array (* 2 size+1)
- :initial-element +empty-ht-slot+))
- (table (%make-hash-table
- :test test
- :test-fun test-fun
- :hash-fun hash-fun
- :rehash-size rehash-size
- :rehash-threshold rehash-threshold
- :rehash-trigger size
- :table kv-vector
- :weak-p weak-p
- :index-vector index-vector
- :next-vector next-vector
- :hash-vector (unless (eq test 'eq)
- (make-array size+1
- :element-type '(unsigned-byte 32)
- ;; as explained by pmai on
- ;; openprojects #lisp IRC
- ;; 2002-07-30: #x80000000 is
- ;; bigger than any possible nonEQ
- ;; hash value, and thus indicates
- ;; an empty slot; and EQ hash
- ;; tables don't use
- ;; HASH-TABLE-HASH-VECTOR
- :initial-element #x80000000)))))
+ ;;
+ ;; Note that this has not yet been audited for
+ ;; correctness. It just seems to work. -- CSR, 2002-11-02
+ (scaled-size (truncate (/ (float size+1) rehash-threshold)))
+ (length (power-of-two-ceiling (max scaled-size
+ (1+ +min-hash-table-size+))))
+ (index-vector (make-array length
+ :element-type
+ '(unsigned-byte #.sb!vm:n-word-bits)
+ :initial-element 0))
+ ;; Needs to be the half the length of the KV vector to link
+ ;; KV entries - mapped to indeces at 2i and 2i+1 -
+ ;; together.
+ (next-vector (make-array size+1
+ :element-type
+ '(unsigned-byte #.sb!vm:n-word-bits)))
+ (kv-vector (make-array (* 2 size+1)
+ :initial-element +empty-ht-slot+))
+ (table (%make-hash-table
+ :test test
+ :test-fun test-fun
+ :hash-fun hash-fun
+ :rehash-size rehash-size
+ :rehash-threshold rehash-threshold
+ :rehash-trigger size
+ :table kv-vector
+ :weakness weakness
+ :index-vector index-vector
+ :next-vector next-vector
+ :hash-vector
+ (unless (eq test 'eq)
+ (make-array size+1
+ :element-type '(unsigned-byte
+ #.sb!vm:n-word-bits)
+ :initial-element +magic-hash-vector-value+))
+ :synchronized-p synchronized)))
(declare (type index size+1 scaled-size length))
;; Set up the free list, all free. These lists are 0 terminated.
(do ((i 1 (1+ i)))
- ((>= i size))
- (setf (aref next-vector i) (1+ i)))
+ ((>= i size))
+ (setf (aref next-vector i) (1+ i)))
(setf (aref next-vector size) 0)
(setf (hash-table-next-free-kv table) 1)
- (setf (hash-table-needing-rehash table) 0)
(setf (aref kv-vector 0) table)
table)))
#!+sb-doc
"Return the number of entries in the given HASH-TABLE."
(declare (type hash-table hash-table)
- (values index))
+ (values index))
(hash-table-number-entries hash-table))
#!+sb-doc
(setf (fdocumentation 'hash-table-rehash-threshold 'function)
"Return the rehash-threshold HASH-TABLE was created with.")
+#!+sb-doc
+(setf (fdocumentation 'hash-table-synchronized-p 'function)
+ "Returns T if HASH-TABLE is synchronized.")
+
(defun hash-table-size (hash-table)
#!+sb-doc
"Return a size that can be used with MAKE-HASH-TABLE to create a hash
"Return the test HASH-TABLE was created with.")
#!+sb-doc
-(setf (fdocumentation 'hash-table-weak-p 'function)
- "Return T if HASH-TABLE will not keep entries for keys that would
- otherwise be garbage, and NIL if it will.")
+(setf (fdocumentation 'hash-table-weakness 'function)
+ "Return the WEAKNESS of HASH-TABLE which is one of NIL, :KEY,
+:VALUE, :KEY-AND-VALUE, :KEY-OR-VALUE.")
+
+;;; Called when we detect circular chains in a hash-table.
+(defun signal-corrupt-hash-table (hash-table)
+ (error "Corrupt NEXT-chain in ~A. This is probably caused by ~
+multiple threads accessing the same hash-table without locking."
+ hash-table))
+
\f
;;;; accessing functions
;;; rehash-size.
(defun rehash (table)
(declare (type hash-table table))
+ (aver *gc-inhibit*)
(let* ((old-kv-vector (hash-table-table table))
- (old-next-vector (hash-table-next-vector table))
- (old-hash-vector (hash-table-hash-vector table))
- (old-size (length old-next-vector))
- (new-size
- (let ((rehash-size (hash-table-rehash-size table)))
- (etypecase rehash-size
- (fixnum
- (+ rehash-size old-size))
- (float
- (the index (truncate (* rehash-size old-size)))))))
- (new-kv-vector (make-array (* 2 new-size)
- :initial-element +empty-ht-slot+))
- (new-next-vector (make-array new-size
- :element-type '(unsigned-byte 32)
- :initial-element 0))
- (new-hash-vector (when old-hash-vector
- (make-array new-size
- :element-type '(unsigned-byte 32)
- :initial-element #x80000000)))
- (old-index-vector (hash-table-index-vector table))
- (new-length (almost-primify
- (truncate (/ (float new-size)
- (hash-table-rehash-threshold table)))))
- (new-index-vector (make-array new-length
- :element-type '(unsigned-byte 32)
- :initial-element 0)))
+ (old-next-vector (hash-table-next-vector table))
+ (old-hash-vector (hash-table-hash-vector table))
+ (old-size (length old-next-vector))
+ (new-size
+ (power-of-two-ceiling
+ (let ((rehash-size (hash-table-rehash-size table)))
+ (etypecase rehash-size
+ (fixnum
+ (+ rehash-size old-size))
+ (float
+ (the index (truncate (* rehash-size old-size))))))))
+ (new-kv-vector (make-array (* 2 new-size)
+ :initial-element +empty-ht-slot+))
+ (new-next-vector
+ (make-array new-size
+ :element-type '(unsigned-byte #.sb!vm:n-word-bits)
+ :initial-element 0))
+ (new-hash-vector
+ (when old-hash-vector
+ (make-array new-size
+ :element-type '(unsigned-byte #.sb!vm:n-word-bits)
+ :initial-element +magic-hash-vector-value+)))
+ (new-length new-size)
+ (new-index-vector
+ (make-array new-length
+ :element-type '(unsigned-byte #.sb!vm:n-word-bits)
+ :initial-element 0)))
(declare (type index new-size new-length old-size))
;; Disable GC tricks on the OLD-KV-VECTOR.
(set-header-data old-kv-vector sb!vm:vector-normal-subtype)
+ ;; Non-empty weak hash tables always need GC support.
+ (when (and (hash-table-weakness table) (plusp (hash-table-count table)))
+ (set-header-data new-kv-vector sb!vm:vector-valid-hashing-subtype))
+
+ ;; FIXME: here and in several other places in the hash table code,
+ ;; loops like this one are used when FILL or REPLACE would be
+ ;; appropriate. why are standard CL functions not used?
+ ;; Performance issues? General laziness? -- NJF, 2004-03-10
+
;; Copy over the kv-vector. The element positions should not move
;; in case there are active scans.
(dotimes (i (* old-size 2))
;; Copy over the hash-vector.
(when old-hash-vector
(dotimes (i old-size)
- (setf (aref new-hash-vector i) (aref old-hash-vector i))))
+ (setf (aref new-hash-vector i) (aref old-hash-vector i))))
(setf (hash-table-next-free-kv table) 0)
- (setf (hash-table-needing-rehash table) 0)
;; Rehash all the entries; last to first so that after the pushes
;; the chains are first to last.
(do ((i (1- new-size) (1- i)))
- ((zerop i))
+ ((zerop i))
+ (declare (type index/2 i))
(let ((key (aref new-kv-vector (* 2 i)))
- (value (aref new-kv-vector (1+ (* 2 i)))))
- (cond ((and (eq key +empty-ht-slot+)
- (eq value +empty-ht-slot+))
- ;; Slot is empty, push it onto the free list.
- (setf (aref new-next-vector i)
- (hash-table-next-free-kv table))
- (setf (hash-table-next-free-kv table) i))
- ((and new-hash-vector
- (not (= (aref new-hash-vector i) #x80000000)))
- ;; Can use the existing hash value (not EQ based)
- (let* ((hashing (aref new-hash-vector i))
- (index (rem hashing new-length))
- (next (aref new-index-vector index)))
- (declare (type index index)
- (type hash hashing))
- ;; Push this slot into the next chain.
- (setf (aref new-next-vector i) next)
- (setf (aref new-index-vector index) i)))
- (t
- ;; EQ base hash.
- ;; Enable GC tricks.
- (set-header-data new-kv-vector
- sb!vm:vector-valid-hashing-subtype)
- (let* ((hashing (pointer-hash key))
- (index (rem hashing new-length))
- (next (aref new-index-vector index)))
- (declare (type index index)
- (type hash hashing))
- ;; Push this slot onto the next chain.
- (setf (aref new-next-vector i) next)
- (setf (aref new-index-vector index) i))))))
+ (value (aref new-kv-vector (1+ (* 2 i)))))
+ (cond ((and (eq key +empty-ht-slot+)
+ (eq value +empty-ht-slot+))
+ ;; Slot is empty, push it onto the free list.
+ (setf (aref new-next-vector i)
+ (hash-table-next-free-kv table))
+ (setf (hash-table-next-free-kv table) i))
+ ((and new-hash-vector
+ (not (= (aref new-hash-vector i)
+ +magic-hash-vector-value+)))
+ ;; Can use the existing hash value (not EQ based)
+ (let* ((hashing (aref new-hash-vector i))
+ (index (index-for-hashing hashing new-length))
+ (next (aref new-index-vector index)))
+ (declare (type index index)
+ (type hash hashing))
+ ;; Push this slot into the next chain.
+ (setf (aref new-next-vector i) next)
+ (setf (aref new-index-vector index) i)))
+ (t
+ ;; EQ base hash.
+ ;; Enable GC tricks.
+ (set-header-data new-kv-vector
+ sb!vm:vector-valid-hashing-subtype)
+ (let* ((hashing (pointer-hash key))
+ (index (index-for-hashing hashing new-length))
+ (next (aref new-index-vector index)))
+ (declare (type index index)
+ (type hash hashing))
+ ;; Push this slot onto the next chain.
+ (setf (aref new-next-vector i) next)
+ (setf (aref new-index-vector index) i))))))
(setf (hash-table-table table) new-kv-vector)
(setf (hash-table-index-vector table) new-index-vector)
(setf (hash-table-next-vector table) new-next-vector)
(setf (hash-table-hash-vector table) new-hash-vector)
- ;; Shrink the old vectors to 0 size to help the conservative GC.
- (shrink-vector old-kv-vector 0)
- (shrink-vector old-index-vector 0)
- (shrink-vector old-next-vector 0)
- (when old-hash-vector
- (shrink-vector old-hash-vector 0))
- (setf (hash-table-rehash-trigger table) new-size))
+ ;; Fill the old kv-vector with 0 to help the conservative GC. Even
+ ;; if nothing else were zeroed, it's important to clear the
+ ;; special first cells in old-kv-vector.
+ (fill old-kv-vector 0)
+ (setf (hash-table-rehash-trigger table) new-size)
+ (setf (hash-table-needs-rehash-p table) nil))
(values))
;;; Use the same size as before, re-using the vectors.
(defun rehash-without-growing (table)
(declare (type hash-table table))
+ (aver *gc-inhibit*)
(let* ((kv-vector (hash-table-table table))
- (next-vector (hash-table-next-vector table))
- (hash-vector (hash-table-hash-vector table))
- (size (length next-vector))
- (index-vector (hash-table-index-vector table))
- (length (length index-vector)))
- (declare (type index size length)
- (type (simple-array (unsigned-byte 32) (*))))
-
- ;; Disable GC tricks, they will be re-enabled during the re-hash
- ;; if necesary.
- (set-header-data kv-vector sb!vm:vector-normal-subtype)
+ (next-vector (hash-table-next-vector table))
+ (hash-vector (hash-table-hash-vector table))
+ (size (length next-vector))
+ (index-vector (hash-table-index-vector table))
+ (length (length index-vector)))
+ (declare (type index size length))
+
+ ;; Non-empty weak hash tables always need GC support.
+ (unless (and (hash-table-weakness table) (plusp (hash-table-count table)))
+ ;; Disable GC tricks, they will be re-enabled during the re-hash
+ ;; if necessary.
+ (set-header-data kv-vector sb!vm:vector-normal-subtype))
;; Rehash all the entries.
(setf (hash-table-next-free-kv table) 0)
- (setf (hash-table-needing-rehash table) 0)
(dotimes (i size)
(setf (aref next-vector i) 0))
(dotimes (i length)
(setf (aref index-vector i) 0))
(do ((i (1- size) (1- i)))
- ((zerop i))
+ ((zerop i))
+ (declare (type index/2 i))
(let ((key (aref kv-vector (* 2 i)))
- (value (aref kv-vector (1+ (* 2 i)))))
- (cond ((and (eq key +empty-ht-slot+)
- (eq value +empty-ht-slot+))
- ;; Slot is empty, push it onto free list.
- (setf (aref next-vector i) (hash-table-next-free-kv table))
- (setf (hash-table-next-free-kv table) i))
- ((and hash-vector (not (= (aref hash-vector i) #x80000000)))
- ;; Can use the existing hash value (not EQ based)
- (let* ((hashing (aref hash-vector i))
- (index (rem hashing length))
- (next (aref index-vector index)))
- (declare (type index index))
- ;; Push this slot into the next chain.
- (setf (aref next-vector i) next)
- (setf (aref index-vector index) i)))
- (t
- ;; EQ base hash.
- ;; Enable GC tricks.
- (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype)
- (let* ((hashing (pointer-hash key))
- (index (rem hashing length))
- (next (aref index-vector index)))
- (declare (type index index)
- (type hash hashing))
- ;; Push this slot into the next chain.
- (setf (aref next-vector i) next)
- (setf (aref index-vector index) i)))))))
+ (value (aref kv-vector (1+ (* 2 i)))))
+ (cond ((and (eq key +empty-ht-slot+)
+ (eq value +empty-ht-slot+))
+ ;; Slot is empty, push it onto free list.
+ (setf (aref next-vector i) (hash-table-next-free-kv table))
+ (setf (hash-table-next-free-kv table) i))
+ ((and hash-vector (not (= (aref hash-vector i)
+ +magic-hash-vector-value+)))
+ ;; Can use the existing hash value (not EQ based)
+ (let* ((hashing (aref hash-vector i))
+ (index (index-for-hashing hashing length))
+ (next (aref index-vector index)))
+ (declare (type index index))
+ ;; Push this slot into the next chain.
+ (setf (aref next-vector i) next)
+ (setf (aref index-vector index) i)))
+ (t
+ ;; EQ base hash.
+ ;; Enable GC tricks.
+ (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype)
+ (let* ((hashing (pointer-hash key))
+ (index (index-for-hashing hashing length))
+ (next (aref index-vector index)))
+ (declare (type index index)
+ (type hash hashing))
+ ;; Push this slot into the next chain.
+ (setf (aref next-vector i) next)
+ (setf (aref index-vector index) i)))))))
+ ;; Clear the rehash bit only at the very end, otherwise another thread
+ ;; might see a partially rehashed table as a normal one.
+ (setf (hash-table-needs-rehash-p table) nil)
(values))
-(defun flush-needing-rehash (table)
- (let* ((kv-vector (hash-table-table table))
- (index-vector (hash-table-index-vector table))
- (next-vector (hash-table-next-vector table))
- (length (length index-vector)))
- (do ((next (hash-table-needing-rehash table)))
- ((zerop next))
- (declare (type index next))
- (let* ((key (aref kv-vector (* 2 next)))
- (hashing (pointer-hash key))
- (index (rem hashing length))
- (temp (aref next-vector next)))
- (setf (aref next-vector next) (aref index-vector index))
- (setf (aref index-vector index) next)
- (setf next temp))))
- (setf (hash-table-needing-rehash table) 0)
- (values))
+(declaim (inline maybe-rehash))
+(defun maybe-rehash (hash-table ensure-free-slot-p)
+ (when (hash-table-weakness hash-table)
+ (aver *gc-inhibit*))
+ (flet ((rehash-p ()
+ (and ensure-free-slot-p
+ (zerop (hash-table-next-free-kv hash-table))))
+ (rehash-without-growing-p ()
+ (hash-table-needs-rehash-p hash-table)))
+ (declare (inline rehash-p rehash-without-growing-p))
+ (cond ((rehash-p)
+ ;; Use recursive locks since for weak tables the lock has
+ ;; already been acquired. GC must be inhibited to prevent
+ ;; the GC from seeing a rehash in progress.
+ (sb!thread::with-recursive-system-lock
+ ((hash-table-lock hash-table) :without-gcing t)
+ ;; Repeat the condition inside the lock to ensure that if
+ ;; two reader threads enter MAYBE-REHASH at the same time
+ ;; only one rehash is performed.
+ (when (rehash-p)
+ (rehash hash-table))))
+ ((rehash-without-growing-p)
+ (sb!thread::with-recursive-system-lock
+ ((hash-table-lock hash-table) :without-gcing t)
+ (when (rehash-without-growing-p)
+ (rehash-without-growing hash-table)))))))
+
+(declaim (inline update-hash-table-cache))
+(defun update-hash-table-cache (hash-table index)
+ (unless (hash-table-weakness hash-table)
+ (setf (hash-table-cache hash-table) index)))
+
+(defmacro with-hash-table-locks ((hash-table
+ &key (operation :write) inline pin
+ (synchronized `(hash-table-synchronized-p ,hash-table)))
+ &body body)
+ (declare (type (member :read :write) operation))
+ (with-unique-names (body-fun)
+ `(flet ((,body-fun ()
+ (with-concurrent-access-check ,hash-table ,operation
+ (locally (declare (inline ,@inline))
+ ,@body))))
+ (if (hash-table-weakness ,hash-table)
+ (sb!thread::with-recursive-system-lock
+ ((hash-table-lock ,hash-table) :without-gcing t)
+ (,body-fun))
+ (with-pinned-objects ,pin
+ (if ,synchronized
+ ;; We use a "system" lock here because it is very
+ ;; slightly faster, as it doesn't re-enable
+ ;; interrupts.
+ (sb!thread::with-recursive-system-lock
+ ((hash-table-lock ,hash-table))
+ (,body-fun))
+ (,body-fun)))))))
(defun gethash (key hash-table &optional default)
#!+sb-doc
- "Finds the entry in HASH-TABLE whose key is KEY and returns the associated
- value and T as multiple values, or returns DEFAULT and NIL if there is no
- such entry. Entries can be added using SETF."
+ "Finds the entry in HASH-TABLE whose key is KEY and returns the
+associated value and T as multiple values, or returns DEFAULT and NIL
+if there is no such entry. Entries can be added using SETF."
(declare (type hash-table hash-table)
- (values t (member t nil)))
- (without-gcing
- (cond ((= (get-header-data (hash-table-table hash-table))
- sb!vm:vector-must-rehash-subtype)
- (rehash-without-growing hash-table))
- ((not (zerop (hash-table-needing-rehash hash-table)))
- (flush-needing-rehash hash-table)))
- ;; Search for key in the hash table.
- (multiple-value-bind (hashing eq-based)
- (funcall (hash-table-hash-fun hash-table) key)
- (declare (type hash hashing))
- (let* ((index-vector (hash-table-index-vector hash-table))
- (length (length index-vector))
- (index (rem hashing length))
- (next (aref index-vector index))
- (table (hash-table-table hash-table))
- (next-vector (hash-table-next-vector hash-table))
- (hash-vector (hash-table-hash-vector hash-table))
- (test-fun (hash-table-test-fun hash-table)))
- (declare (type index index))
- ;; Search next-vector chain for a matching key.
- (if (or eq-based (not hash-vector))
- (do ((next next (aref next-vector next)))
- ((zerop next) (values default nil))
- (declare (type index next))
- (when (eq key (aref table (* 2 next)))
- (return (values (aref table (1+ (* 2 next))) t))))
- (do ((next next (aref next-vector next)))
- ((zerop next) (values default nil))
- (declare (type index next))
- (when (and (= hashing (aref hash-vector next))
- (funcall test-fun key (aref table (* 2 next))))
- ;; Found.
- (return (values (aref table (1+ (* 2 next))) t)))))))))
+ (values t (member t nil)))
+ (gethash3 key hash-table default))
+
+(declaim (maybe-inline %gethash3))
+(defun %gethash3 (key hash-table default)
+ (declare (type hash-table hash-table)
+ (optimize speed)
+ (values t (member t nil)))
+ (tagbody
+ start
+ (let ((start-epoch sb!kernel::*gc-epoch*))
+ (macrolet ((result (value foundp)
+ ;; When the table has multiple concurrent readers,
+ ;; it's possible that there was a GC after this
+ ;; thread called MAYBE-REHASH from %GETHASH3, and
+ ;; some other thread then rehashed the table. If
+ ;; this happens, we might not find the key even if
+ ;; it's in the table. To protect against this,
+ ;; redo the lookup if the GC epoch counter has changed.
+ ;; -- JES, 2007-09-30
+ `(if (and (not ,foundp)
+ (not (eq start-epoch sb!kernel::*gc-epoch*)))
+ (go start)
+ (return-from %gethash3 (values ,value ,foundp))))
+ (overflow ()
+ ;; The next-vector chain is circular. This is caused
+ ;; caused by thread-unsafe mutations of the table.
+ `(signal-corrupt-hash-table hash-table)))
+ (maybe-rehash hash-table nil)
+ ;; Note that it's OK for a GC + a REHASH-WITHOUT-GROWING to
+ ;; be triggered by another thread after this point, since the
+ ;; GC epoch check will catch it.
+ (let ((cache (hash-table-cache hash-table))
+ (table (hash-table-table hash-table)))
+ ;; First check the cache. Use EQ here for speed.
+ (if (and cache
+ (< cache (length table))
+ (eq (aref table cache) key))
+ (let ((value (aref table (1+ cache))))
+ (result value t))
+ ;; Search for key in the hash table.
+ (multiple-value-bind (hashing eq-based)
+ (funcall (hash-table-hash-fun hash-table) key)
+ (declare (type hash hashing))
+ (let* ((index-vector (hash-table-index-vector hash-table))
+ (length (length index-vector))
+ (index (index-for-hashing hashing length))
+ (next (aref index-vector index))
+ (next-vector (hash-table-next-vector hash-table))
+ (hash-vector (hash-table-hash-vector hash-table))
+ (test-fun (hash-table-test-fun hash-table)))
+ (declare (type index index))
+ ;; Search next-vector chain for a matching key.
+ (if (or eq-based (not hash-vector))
+ (do ((next next (aref next-vector next))
+ (i 0 (1+ i)))
+ ((zerop next) (result default nil))
+ (declare (type index/2 next i))
+ (when (> i length)
+ (overflow))
+ (when (eq key (aref table (* 2 next)))
+ (update-hash-table-cache hash-table (* 2 next))
+ (let ((value (aref table (1+ (* 2 next)))))
+ (result value t))))
+ (do ((next next (aref next-vector next))
+ (i 0 (1+ i)))
+ ((zerop next) (result default nil))
+ (declare (type index/2 next i))
+ (when (> i length)
+ (overflow))
+ (when (and (= hashing (aref hash-vector next))
+ (funcall test-fun key
+ (aref table (* 2 next))))
+ ;; Found.
+ (update-hash-table-cache hash-table (* 2 next))
+ (let ((value (aref table (1+ (* 2 next)))))
+ (result value t)))))))))))))
+
+(defun gethash3 (key hash-table default)
+ "Three argument version of GETHASH"
+ (declare (type hash-table hash-table))
+ (with-hash-table-locks (hash-table :operation :read :inline (%gethash3)
+ :pin (key))
+ (%gethash3 key hash-table default)))
;;; so people can call #'(SETF GETHASH)
(defun (setf gethash) (new-value key table &optional default)
(declare (ignore default))
(%puthash key table new-value))
+(declaim (maybe-inline %%puthash))
+(defun %%puthash (key hash-table value)
+ (declare (optimize speed))
+ ;; We need to rehash here so that a current key can be found if it
+ ;; exists. Check that there is room for one more entry. May not be
+ ;; needed if the key is already present.
+ (maybe-rehash hash-table t)
+ ;; Search for key in the hash table.
+ (multiple-value-bind (hashing eq-based)
+ (funcall (hash-table-hash-fun hash-table) key)
+ (declare (type hash hashing))
+ (let* ((index-vector (hash-table-index-vector hash-table))
+ (length (length index-vector))
+ (index (index-for-hashing hashing length))
+ (next (aref index-vector index))
+ (kv-vector (hash-table-table hash-table))
+ (next-vector (hash-table-next-vector hash-table))
+ (hash-vector (hash-table-hash-vector hash-table))
+ (test-fun (hash-table-test-fun hash-table)))
+ (declare (type index index next))
+ (when (hash-table-weakness hash-table)
+ (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype))
+ (cond ((or eq-based (not hash-vector))
+ (when eq-based
+ (set-header-data kv-vector
+ sb!vm:vector-valid-hashing-subtype))
+ ;; Search next-vector chain for a matching key.
+ (do ((next next (aref next-vector next))
+ (i 0 (1+ i)))
+ ((zerop next))
+ (declare (type index/2 next i))
+ (when (> i length)
+ (signal-corrupt-hash-table hash-table))
+ (when (eq key (aref kv-vector (* 2 next)))
+ ;; Found, just replace the value.
+ (update-hash-table-cache hash-table (* 2 next))
+ (setf (aref kv-vector (1+ (* 2 next))) value)
+ (return-from %%puthash value))))
+ (t
+ ;; Search next-vector chain for a matching key.
+ (do ((next next (aref next-vector next))
+ (i 0 (1+ i)))
+ ((zerop next))
+ (declare (type index/2 next i))
+ (when (> i length)
+ (signal-corrupt-hash-table hash-table))
+ (when (and (= hashing (aref hash-vector next))
+ (funcall test-fun key
+ (aref kv-vector (* 2 next))))
+ ;; Found, just replace the value.
+ (update-hash-table-cache hash-table (* 2 next))
+ (setf (aref kv-vector (1+ (* 2 next))) value)
+ (return-from %%puthash value)))))
+ ;; Pop a KV slot off the free list
+ (let ((free-kv-slot (hash-table-next-free-kv hash-table)))
+ (declare (type index/2 free-kv-slot))
+ ;; Double-check for overflow.
+ (aver (not (zerop free-kv-slot)))
+ (setf (hash-table-next-free-kv hash-table)
+ (aref next-vector free-kv-slot))
+ (incf (hash-table-number-entries hash-table))
+ (update-hash-table-cache hash-table (* 2 free-kv-slot))
+ (setf (aref kv-vector (* 2 free-kv-slot)) key)
+ (setf (aref kv-vector (1+ (* 2 free-kv-slot))) value)
+ ;; Setup the hash-vector if necessary.
+ (when hash-vector
+ (if (not eq-based)
+ (setf (aref hash-vector free-kv-slot) hashing)
+ (aver (= (aref hash-vector free-kv-slot)
+ +magic-hash-vector-value+))))
+ ;; Push this slot into the next chain.
+ (setf (aref next-vector free-kv-slot) next)
+ (setf (aref index-vector index) free-kv-slot)))
+ value))
+
(defun %puthash (key hash-table value)
(declare (type hash-table hash-table))
(aver (hash-table-index-vector hash-table))
- (without-gcing
- ;; We need to rehash here so that a current key can be found if it
- ;; exists. Check that there is room for one more entry. May not be
- ;; needed if the key is already present.
- (cond ((zerop (hash-table-next-free-kv hash-table))
- (rehash hash-table))
- ((= (get-header-data (hash-table-table hash-table))
- sb!vm:vector-must-rehash-subtype)
- (rehash-without-growing hash-table))
- ((not (zerop (hash-table-needing-rehash hash-table)))
- (flush-needing-rehash hash-table)))
-
- ;; Search for key in the hash table.
- (multiple-value-bind (hashing eq-based)
- (funcall (hash-table-hash-fun hash-table) key)
- (declare (type hash hashing))
- (let* ((index-vector (hash-table-index-vector hash-table))
- (length (length index-vector))
- (index (rem hashing length))
- (next (aref index-vector index))
- (kv-vector (hash-table-table hash-table))
- (next-vector (hash-table-next-vector hash-table))
- (hash-vector (hash-table-hash-vector hash-table))
- (test-fun (hash-table-test-fun hash-table)))
- (declare (type index index))
-
- (cond ((or eq-based (not hash-vector))
- (when eq-based
- (set-header-data kv-vector sb!vm:vector-valid-hashing-subtype))
-
- ;; Search next-vector chain for a matching key.
- (do ((next next (aref next-vector next)))
- ((zerop next))
- (declare (type index next))
- (when (eq key (aref kv-vector (* 2 next)))
- ;; Found, just replace the value.
- (setf (aref kv-vector (1+ (* 2 next))) value)
- (return-from %puthash value))))
- (t
- ;; Search next-vector chain for a matching key.
- (do ((next next (aref next-vector next)))
- ((zerop next))
- (declare (type index next))
- (when (and (= hashing (aref hash-vector next))
- (funcall test-fun key
- (aref kv-vector (* 2 next))))
- ;; Found, just replace the value.
- (setf (aref kv-vector (1+ (* 2 next))) value)
- (return-from %puthash value)))))
-
- ;; Pop a KV slot off the free list
- (let ((free-kv-slot (hash-table-next-free-kv hash-table)))
- ;; Double-check for overflow.
- (aver (not (zerop free-kv-slot)))
- (setf (hash-table-next-free-kv hash-table)
- (aref next-vector free-kv-slot))
- (incf (hash-table-number-entries hash-table))
-
- (setf (aref kv-vector (* 2 free-kv-slot)) key)
- (setf (aref kv-vector (1+ (* 2 free-kv-slot))) value)
-
- ;; Setup the hash-vector if necessary.
- (when hash-vector
- (if (not eq-based)
- (setf (aref hash-vector free-kv-slot) hashing)
- (aver (= (aref hash-vector free-kv-slot) #x80000000))))
-
- ;; Push this slot into the next chain.
- (setf (aref next-vector free-kv-slot) next)
- (setf (aref index-vector index) free-kv-slot)))))
- value)
+ (macrolet ((put-it (lockedp)
+ `(let ((cache (hash-table-cache hash-table))
+ (kv-vector (hash-table-table hash-table)))
+ ;; Check the cache
+ (if (and cache
+ (< cache (length kv-vector))
+ (eq (aref kv-vector cache) key))
+ ;; If cached, just store here
+ (setf (aref kv-vector (1+ cache)) value)
+ ;; Otherwise do things the hard way
+ ,(if lockedp
+ '(%%puthash key hash-table value)
+ '(with-hash-table-locks
+ (hash-table :inline (%%puthash) :pin (key)
+ :synchronized nil)
+ (%%puthash key hash-table value)))))))
+ (if (hash-table-synchronized-p hash-table)
+ (with-hash-table-locks (hash-table :pin (key) :synchronized t)
+ (put-it t))
+ (put-it nil))))
+
+(declaim (maybe-inline %remhash))
+(defun %remhash (key hash-table)
+ ;; We need to rehash here so that a current key can be found if it
+ ;; exists.
+ ;;
+ ;; Note that if a GC happens after MAYBE-REHASH returns and another
+ ;; thread the accesses the table (triggering a rehash), we might not
+ ;; find the key even if it is in the table. But that's ok, since the
+ ;; only concurrent case that we safely allow is multiple readers
+ ;; with no writers.
+ (maybe-rehash hash-table nil)
+ ;; Search for key in the hash table.
+ (multiple-value-bind (hashing eq-based)
+ (funcall (hash-table-hash-fun hash-table) key)
+ (declare (type hash hashing))
+ (let* ((index-vector (hash-table-index-vector hash-table))
+ (length (length index-vector))
+ (index (index-for-hashing hashing length))
+ (next (aref index-vector index))
+ (table (hash-table-table hash-table))
+ (next-vector (hash-table-next-vector hash-table))
+ (hash-vector (hash-table-hash-vector hash-table))
+ (test-fun (hash-table-test-fun hash-table)))
+ (declare (type index index)
+ (type index/2 next))
+ (flet ((clear-slot (chain-vector prior-slot-location slot-location)
+ (declare (type index/2 slot-location))
+ ;; Mark slot as empty.
+ (setf (aref table (* 2 slot-location)) +empty-ht-slot+
+ (aref table (1+ (* 2 slot-location))) +empty-ht-slot+)
+ ;; Update the prior pointer in the chain to skip this.
+ (setf (aref chain-vector prior-slot-location)
+ (aref next-vector slot-location))
+ ;; Push KV slot onto free chain.
+ (setf (aref next-vector slot-location)
+ (hash-table-next-free-kv hash-table))
+ (setf (hash-table-next-free-kv hash-table) slot-location)
+ (when hash-vector
+ (setf (aref hash-vector slot-location)
+ +magic-hash-vector-value+))
+ ;; On parallel accesses this may turn out to be a
+ ;; type-error, so don't turn down the safety!
+ (decf (hash-table-number-entries hash-table))
+ t))
+ (cond ((zerop next)
+ nil)
+ ((if (or eq-based (not hash-vector))
+ (eq key (aref table (* 2 next)))
+ (and (= hashing (aref hash-vector next))
+ (funcall test-fun key (aref table (* 2 next)))))
+ (clear-slot index-vector index next))
+ ;; Search next-vector chain for a matching key.
+ ((or eq-based (not hash-vector))
+ ;; EQ based
+ (do ((prior next next)
+ (i 0 (1+ i))
+ (next (aref next-vector next) (aref next-vector next)))
+ ((zerop next) nil)
+ (declare (type index next))
+ (when (> i length)
+ (signal-corrupt-hash-table hash-table))
+ (when (eq key (aref table (* 2 next)))
+ (return-from %remhash (clear-slot next-vector prior next)))))
+ (t
+ ;; not EQ based
+ (do ((prior next next)
+ (i 0 (1+ i))
+ (next (aref next-vector next) (aref next-vector next)))
+ ((zerop next) nil)
+ (declare (type index/2 next))
+ (when (> i length)
+ (signal-corrupt-hash-table hash-table))
+ (when (and (= hashing (aref hash-vector next))
+ (funcall test-fun key (aref table (* 2 next))))
+ (return-from %remhash
+ (clear-slot next-vector prior next))))))))))
(defun remhash (key hash-table)
#!+sb-doc
- "Remove the entry in HASH-TABLE associated with KEY. Return T if there
- was such an entry, or NIL if not."
+ "Remove the entry in HASH-TABLE associated with KEY. Return T if
+there was such an entry, or NIL if not."
(declare (type hash-table hash-table)
- (values (member t nil)))
- (without-gcing
- ;; We need to rehash here so that a current key can be found if it
- ;; exists.
- (cond ((= (get-header-data (hash-table-table hash-table))
- sb!vm:vector-must-rehash-subtype)
- (rehash-without-growing hash-table))
- ((not (zerop (hash-table-needing-rehash hash-table)))
- (flush-needing-rehash hash-table)))
-
- ;; Search for key in the hash table.
- (multiple-value-bind (hashing eq-based)
- (funcall (hash-table-hash-fun hash-table) key)
- (declare (type hash hashing))
- (let* ((index-vector (hash-table-index-vector hash-table))
- (length (length index-vector))
- (index (rem hashing length))
- (next (aref index-vector index))
- (table (hash-table-table hash-table))
- (next-vector (hash-table-next-vector hash-table))
- (hash-vector (hash-table-hash-vector hash-table))
- (test-fun (hash-table-test-fun hash-table)))
- (declare (type index index next))
- (cond ((zerop next)
- nil)
- ((if (or eq-based (not hash-vector))
- (eq key (aref table (* 2 next)))
- (and (= hashing (aref hash-vector next))
- (funcall test-fun key (aref table (* 2 next)))))
-
- ;; FIXME: Substantially the same block of code seems to
- ;; appear in all three cases. (In the first case, it
- ;; appear bare; in the other two cases, it's wrapped in
- ;; DO.) It should be defined in a separate (possibly
- ;; inline) DEFUN or FLET.
-
- ;; Mark slot as empty.
- (setf (aref table (* 2 next)) +empty-ht-slot+
- (aref table (1+ (* 2 next))) +empty-ht-slot+)
- ;; Update the index-vector pointer.
- (setf (aref index-vector index) (aref next-vector next))
- ;; Push KV slot onto free chain.
- (setf (aref next-vector next)
- (hash-table-next-free-kv hash-table))
- (setf (hash-table-next-free-kv hash-table) next)
- (when hash-vector
- (setf (aref hash-vector next) #x80000000))
- (decf (hash-table-number-entries hash-table))
- t)
- ;; Search next-vector chain for a matching key.
- ((or eq-based (not hash-vector))
- ;; EQ based
- (do ((prior next next)
- (next (aref next-vector next) (aref next-vector next)))
- ((zerop next) nil)
- (declare (type index next))
- (when (eq key (aref table (* 2 next)))
- ;; Mark slot as empty.
- (setf (aref table (* 2 next)) +empty-ht-slot+
- (aref table (1+ (* 2 next))) +empty-ht-slot+)
- ;; Update the prior pointer in the chain to skip this.
- (setf (aref next-vector prior) (aref next-vector next))
- ;; Push KV slot onto free chain.
- (setf (aref next-vector next)
- (hash-table-next-free-kv hash-table))
- (setf (hash-table-next-free-kv hash-table) next)
- (when hash-vector
- (setf (aref hash-vector next) #x80000000))
- (decf (hash-table-number-entries hash-table))
- (return t))))
- (t
- ;; not EQ based
- (do ((prior next next)
- (next (aref next-vector next) (aref next-vector next)))
- ((zerop next) nil)
- (declare (type index next))
- (when (and (= hashing (aref hash-vector next))
- (funcall test-fun key (aref table (* 2 next))))
- ;; Mark slot as empty.
- (setf (aref table (* 2 next)) +empty-ht-slot+)
- (setf (aref table (1+ (* 2 next))) +empty-ht-slot+)
- ;; Update the prior pointer in the chain to skip this.
- (setf (aref next-vector prior) (aref next-vector next))
- ;; Push KV slot onto free chain.
- (setf (aref next-vector next)
- (hash-table-next-free-kv hash-table))
- (setf (hash-table-next-free-kv hash-table) next)
- (when hash-vector
- (setf (aref hash-vector next) #x80000000))
- (decf (hash-table-number-entries hash-table))
- (return t)))))))))
+ (values (member t nil)))
+ (with-hash-table-locks (hash-table :inline (%remhash) :pin (key))
+ ;; For now, just clear the cache
+ (setf (hash-table-cache hash-table) nil)
+ (%remhash key hash-table)))
(defun clrhash (hash-table)
#!+sb-doc
- "This removes all the entries from HASH-TABLE and returns the hash table
- itself."
- (let* ((kv-vector (hash-table-table hash-table))
- (kv-length (length kv-vector))
- (next-vector (hash-table-next-vector hash-table))
- (hash-vector (hash-table-hash-vector hash-table))
- (size (length next-vector))
- (index-vector (hash-table-index-vector hash-table))
- (length (length index-vector)))
- ;; Disable GC tricks.
- (set-header-data kv-vector sb!vm:vector-normal-subtype)
- ;; Mark all slots as empty by setting all keys and values to magic
- ;; tag.
- (do ((i 2 (1+ i)))
- ((>= i kv-length))
- (setf (aref kv-vector i) +empty-ht-slot+))
- (aver (eq (aref kv-vector 0) hash-table))
- ;; Set up the free list, all free.
- (do ((i 1 (1+ i)))
- ((>= i (1- size)))
- (setf (aref next-vector i) (1+ i)))
- (setf (aref next-vector (1- size)) 0)
- (setf (hash-table-next-free-kv hash-table) 1)
- (setf (hash-table-needing-rehash hash-table) 0)
- ;; Clear the index-vector.
- (dotimes (i length)
- (setf (aref index-vector i) 0))
- ;; Clear the hash-vector.
- (when hash-vector
- (dotimes (i size)
- (setf (aref hash-vector i) #x80000000))))
- (setf (hash-table-number-entries hash-table) 0)
+ "This removes all the entries from HASH-TABLE and returns the hash
+table itself."
+ (when (plusp (hash-table-number-entries hash-table))
+ (with-hash-table-locks (hash-table)
+ (let* ((kv-vector (hash-table-table hash-table))
+ (next-vector (hash-table-next-vector hash-table))
+ (hash-vector (hash-table-hash-vector hash-table))
+ (size (length next-vector))
+ (index-vector (hash-table-index-vector hash-table)))
+ ;; Disable GC tricks.
+ (set-header-data kv-vector sb!vm:vector-normal-subtype)
+ ;; Mark all slots as empty by setting all keys and values to magic
+ ;; tag.
+ (aver (eq (aref kv-vector 0) hash-table))
+ (fill kv-vector +empty-ht-slot+ :start 2)
+ ;; Set up the free list, all free.
+ (do ((i 1 (1+ i)))
+ ((>= i (1- size)))
+ (setf (aref next-vector i) (1+ i)))
+ (setf (aref next-vector (1- size)) 0)
+ (setf (hash-table-next-free-kv hash-table) 1)
+ ;; Clear the index-vector.
+ (fill index-vector 0)
+ ;; Clear the hash-vector.
+ (when hash-vector
+ (fill hash-vector +magic-hash-vector-value+)))
+ (setf (hash-table-cache hash-table) nil)
+ (setf (hash-table-number-entries hash-table) 0)))
hash-table)
+
\f
;;;; MAPHASH
(declaim (inline maphash))
(defun maphash (function-designator hash-table)
#!+sb-doc
- "For each entry in HASH-TABLE, call the designated two-argument function
- on the key and value of the entry. Return NIL."
+ "For each entry in HASH-TABLE, call the designated two-argument function on
+the key and value of the entry. Return NIL.
+
+Consequences are undefined if HASH-TABLE is mutated during the call to
+MAPHASH, except for changing or removing elements corresponding to the
+current key. The applies to all threads, not just the current one --
+even for synchronized hash-tables. If the table may be mutated by
+another thread during iteration, use eg. SB-EXT:WITH-LOCKED-HASH-TABLE
+to protect the MAPHASH call."
+ ;; This essentially duplicates WITH-HASH-TABLE-ITERATOR, so
+ ;; any changes here should be reflected there as well.
(let ((fun (%coerce-callable-to-fun function-designator))
- (size (length (hash-table-next-vector hash-table))))
+ (size (length (hash-table-next-vector hash-table))))
(declare (type function fun))
(do ((i 1 (1+ i)))
- ((>= i size))
- (declare (type index i))
+ ((>= i size))
+ (declare (type index/2 i))
(let* ((kv-vector (hash-table-table hash-table))
- (key (aref kv-vector (* 2 i)))
- (value (aref kv-vector (1+ (* 2 i)))))
- (unless (and (eq key +empty-ht-slot+)
- (eq value +empty-ht-slot+))
- (funcall fun key value))))))
+ (key (aref kv-vector (* 2 i)))
+ (value (aref kv-vector (1+ (* 2 i)))))
+ ;; We are running without locking or WITHOUT-GCING. For a weak
+ ;; :VALUE hash table it's possible that the GC hit after KEY
+ ;; was read and now the entry is gone. So check if either the
+ ;; key or the value is empty.
+ (unless (or (eq key +empty-ht-slot+)
+ (eq value +empty-ht-slot+))
+ (funcall fun key value))))))
\f
;;;; methods on HASH-TABLE
;;; Return a list of keyword args and values to use for MAKE-HASH-TABLE
;;; when reconstructing HASH-TABLE.
(defun %hash-table-ctor-args (hash-table)
- (when (hash-table-weak-p hash-table)
- ;; FIXME: This might actually work with no trouble, but as of
- ;; sbcl-0.6.12.10 when this code was written, weak hash tables
- ;; weren't working yet, so I couldn't test it. When weak hash
- ;; tables are supported again, this should be fixed.
- (error "can't dump weak hash tables readably")) ; defensive programming..
`(:test ',(hash-table-test hash-table)
:size ',(hash-table-size hash-table)
:rehash-size ',(hash-table-rehash-size hash-table)
- :rehash-threshold ',(hash-table-rehash-threshold hash-table)))
+ :rehash-threshold ',(hash-table-rehash-threshold hash-table)
+ :weakness ',(hash-table-weakness hash-table)))
;;; Return an association list representing the same data as HASH-TABLE.
(defun %hash-table-alist (hash-table)
(let ((result nil))
(maphash (lambda (key value)
- (push (cons key value) result))
- hash-table)
+ (push (cons key value) result))
+ hash-table)
result))
;;; Stuff an association list into HASH-TABLE. Return the hash table,
(def!method print-object ((hash-table hash-table) stream)
(declare (type stream stream))
- (cond ((not *print-readably*)
- (print-unreadable-object (hash-table stream :type t :identity t)
- (format stream
- ":TEST ~S :COUNT ~S"
- (hash-table-test hash-table)
- (hash-table-count hash-table))))
- ((not *read-eval*)
- (error "can't print hash tables readably without *READ-EVAL*"))
- (t
- (with-standard-io-syntax
- (format stream
- "#.~W"
- `(%stuff-hash-table (make-hash-table ,@(%hash-table-ctor-args
- hash-table))
- ',(%hash-table-alist hash-table)))))))
+ (cond ((or (not *print-readably*) (not *read-eval*))
+ (print-unreadable-object (hash-table stream :type t :identity t)
+ (format stream
+ ":TEST ~S :COUNT ~S~@[ :WEAKNESS ~S~]"
+ (hash-table-test hash-table)
+ (hash-table-count hash-table)
+ (hash-table-weakness hash-table))))
+ (t
+ (write-string "#." stream)
+ (write `(%stuff-hash-table (make-hash-table ,@(%hash-table-ctor-args
+ hash-table))
+ ',(%hash-table-alist hash-table))
+ :stream stream))))
(def!method make-load-form ((hash-table hash-table) &optional environment)
(declare (ignore environment))
(values `(make-hash-table ,@(%hash-table-ctor-args hash-table))
- `(%stuff-hash-table ,hash-table ',(%hash-table-alist hash-table))))
+ `(%stuff-hash-table ,hash-table ',(%hash-table-alist hash-table))))
+
+\f
projects / sbcl.git / blobdiff