Custom Query (1030 matches)

Qt-webkit uses pthread_key_create with a destructor, and inside that destructor it calls back into lisp. But apparently lisp-thread infrastructure is already dismantled when the destructor is called.

Here's a test-case:

// gcc test.c -lpthread -shared -o test.so -fPIC

#include <pthread.h>

void finish(void* arg) {
  int (*f)(int, int) = (int(*)(int,int))arg;
  f(1,2);
}

int test (int (*f)(int, int))
{
  pthread_key_t key;
  pthread_key_create(&key, finish);
  pthread_setspecific(key, f);
}

(eval-when (:compile-toplevel :load-toplevel :execute)
  (asdf:load-system :cffi))

(cffi:load-foreign-library "/tmp/test.so")

(cffi:defcfun (test-c "test") :int
  (function :pointer))

(cffi:defcallback (test-callback)
    :short ((a :int) (b :int))
  (print (list a b))
  (finish-output)
  1)

(defun test ()
  (ccl:process-run-function
   nil
   (lambda () (test-c (cffi:get-callback 'test-callback)))))

(test)

One idea I had for fixing this is creating a new thread-key with a value of 1. The order of destructor execution is not specified, but it's specified that they are called PTHREAD_DESTRUCTOR_ITERATIONS times if the key still has a value. So, when the destructor is called the first time, it'll just set its value to 0 and do nothing, then when it's called with 0, do thread clean up. That way other key destructor will get a chance to be called on the first iteration before the clean up is completed.

(remove-if #'name-char
           '((#x00 "Nul") (#x01 "Soh") (#x02 "Stx") (#x03 "Etx") (#x04 "Eot")
             (#x05 "Enq") (#x06 "Ack") (#x07 "Bel") (#x08 "Bs") (#x09 "Ht") (#x0A "Lf")
             (#x0B "Vt") (#x0C "Ff") (#x0D "Cr") (#x0E "So") (#x0F "Si")
             (#x10 "Dle") (#x11 "Dc1") (#x12 "Dc2") (#x13 "Dc3") (#x14 "Dc4")
             (#x15 "Nak") (#x16 "Syn") (#x17 "Etb") (#x18 "Can") (#x19 "Em")
             (#x1A "Sub") (#x1B "Esc") (#x1C "Fs") (#x1D "Gs") (#x1E "Rs")
             (#x1F "Us") (#x20 "Sp") (#x7f "Del"))
           :key #'second)

((16 "Dle") (17 "Dc1") (18 "Dc2") (19 "Dc3")
 (20 "Dc4") (21 "Nak") (22 "Syn") (23 "Etb") (24 "Can") (25 "Em") (32 "Sp"))

Welcome to Clozure Common Lisp Version 1.9-dev-r15596  (DarwinX8664)!
? (equal #p"/" #p"ccl:")
T

That would seem to be wrong.