X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fassembly%2Fx86%2Falloc.lisp;h=65cfdb066d6e0610c785d80bed9744e0123d8991;hb=95591ed483dbb8c0846c129953acac1554f28809;hp=ca62f9274c46767d649a268a2669f049f87acbfd;hpb=28a6f6aef7408e55853f54f8603a259b7320b084;p=sbcl.git

diff --git a/src/assembly/x86/alloc.lisp b/src/assembly/x86/alloc.lisp
index ca62f92..65cfdb0 100644
--- a/src/assembly/x86/alloc.lisp
+++ b/src/assembly/x86/alloc.lisp
@@ -78,3 +78,56 @@
                                                          (intern (aref *dword-register-names* tn-offset)))
                        routines)))))
   (frob-cons-routines))
+
+#+sb-assembling
+(macrolet
+    ((def (reg)
+       (declare (ignorable reg))
+       #!+sb-thread
+       (let* ((name (intern (format nil "ALLOC-TLS-INDEX-IN-~A" reg)))
+              (target-offset (intern (format nil "~A-OFFSET" reg)))
+              (other-offset (if (eql 'eax reg)
+                                'ecx-offset
+                                'eax-offset)))
+         ;; Symbol starts in TARGET, where the TLS-INDEX ends up in.
+         `(define-assembly-routine ,name
+              ((:temp other descriptor-reg ,other-offset)
+               (:temp target descriptor-reg ,target-offset))
+            (let ((get-tls-index-lock (gen-label))
+                  (release-tls-index-lock (gen-label)))
+              (pseudo-atomic
+               ;; Save OTHER & push the symbol. EAX is either one of the two.
+               (inst push other)
+               (inst push target)
+               (emit-label get-tls-index-lock)
+               (inst mov target 1)
+               (inst xor eax-tn eax-tn)
+               (inst cmpxchg (make-ea-for-symbol-value *tls-index-lock*) target :lock)
+               (inst jmp :ne get-tls-index-lock)
+               ;; The symbol is now in OTHER.
+               (inst pop other)
+               ;; Now with the lock held, see if the symbol's tls index has been
+               ;; set in the meantime.
+               (loadw target other symbol-tls-index-slot other-pointer-lowtag)
+               (inst or target target)
+               (inst jmp :ne release-tls-index-lock)
+               ;; Allocate a new tls-index.
+               (load-symbol-value target *free-tls-index*)
+               (let ((error (generate-error-code nil 'tls-exhausted-error)))
+                 (inst cmp target (fixnumize tls-size))
+                 (inst jmp :ge error))
+               (inst add (make-ea-for-symbol-value *free-tls-index*)
+                     (fixnumize 1))
+               (storew target other symbol-tls-index-slot other-pointer-lowtag)
+               (emit-label release-tls-index-lock)
+               ;; No need for barriers on x86/x86-64 on unlock.
+               (store-symbol-value 0 *tls-index-lock*)
+               ;; Restore OTHER.
+               (inst pop other))
+              (inst ret))))))
+  (def eax)
+  (def ebx)
+  (def ecx)
+  (def edx)
+  (def edi)
+  (def esi))