The Tor Browser: build/stlport/src/cxa.c@b8a032363ba2 (annotated)

build/stlport/src/cxa.c@b8a032363ba2 (annotated)

build/stlport/src/cxa.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 #include "stlport_prefix.h"
 #if defined(__unix) && defined(__GNUC__)
 #ifdef __FreeBSD__
 #  include <osreldate.h>
 #endif
 #if (defined(__FreeBSD__) && (__FreeBSD_version < 503001)) || defined(__sun) || defined (__hpux)
 /* Note: __cxa_finalize and __cxa_atexit present in libc in FreeBSD 5.3 */
 #include <stdlib.h>
 #include <stdio.h>
 #include <pthread.h>
 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@" "STLPORT_5_0_0"); */
 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@@" "STLPORT_5_0_0"); */
 /* Not atomic! */
 /* But we can use static mutexes here: I hope that performance issue isn't very
    significant on unloading (for only few calls, ~10) - ptr */
 /*
 #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
   ({ __typeof (mem) __gmemp = (mem);                                  \
      __typeof (*mem) __gnewval = (newval);                            \
                                                                       \
      *__gmemp == (oldval) ? (*__gmemp = __gnewval, 0) : 1; })
 */
 enum {
   ef_free, /* `ef_free' MUST be zero!  */
   ef_us,
   ef_on,
   ef_at,
   ef_cxa
 };
 struct exit_function
 {
   /* `flavour' should be of type of the `enum' above but since we need
      this element in an atomic operation we have to use `long int'.  */
   long int flavor;
   union {
     void (*at)(void);
     struct {
       void (*fn)(int status, void *arg);
       void *arg;
     } on;
     struct {
       void (*fn)(void *arg, int status);
       void *arg;
       void *dso_handle;
     } cxa;
   } func;
 };
 struct exit_function_list
 {
   struct exit_function_list *next;
   size_t idx;
   struct exit_function fns[32];
 };
 struct exit_function *__new_exitfn (void);
 /* Register a function to be called by exit or when a shared library
    is unloaded.  This function is only called from code generated by
    the C++ compiler.  */
 int __cxa_atexit(void (*func)(void *), void *arg, void *d)
 {
   struct exit_function *new = __new_exitfn ();
   if ( new == NULL )
     return -1;
   new->flavor = ef_cxa;
   new->func.cxa.fn = (void (*) (void *, int)) func;
   new->func.cxa.arg = arg;
   new->func.cxa.dso_handle = d;
   return 0;
 }
 /* We change global data, so we need locking.  */
 #ifdef __linux__
 static pthread_mutex_t lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
 #endif
 /* #ifdef __FreeBSD__ */
 #if 0
 static pthread_mutex_t lock =
   { PTHREAD_MUTEX_RECURSIVE /* PTHREAD_MUTEX_DEFAULT */, PTHREAD_PRIO_NONE, {NULL,NULL},
     NULL, { NULL }, /* MUTEX_FLAGS_PRIVATE */ 0x1, 0, 0, 0, {NULL, NULL},
     { 0, 0, 0, 0 } };
 #endif
 #ifdef __sun
 static pthread_mutex_t lock =
   {{0, 0, 0, PTHREAD_MUTEX_RECURSIVE, _MUTEX_MAGIC}, {{{0}}}, 0};
 #endif
 #ifdef __hpux
 static pthread_mutex_t lock = PTHREAD_MUTEX_RECURSIVE_INITIALIZER_NP;
 #  ifdef __ia64
 void *__dso_handle = (void *) &__dso_handle;
 #  endif
 #endif
 static struct exit_function_list initial;
 struct exit_function_list *__exit_funcs = &initial;
 struct exit_function *__new_exitfn(void)
 {
   struct exit_function_list *l;
   size_t i = 0;
 #ifndef __FreeBSD__
   pthread_mutex_lock( &lock );
 #endif
   for (l = __exit_funcs; l != NULL; l = l->next) {
     for (i = 0; i < l->idx; ++i)
       if (l->fns[i].flavor == ef_free)
         break;
     if ( i < l->idx )
       break;
     if (l->idx < sizeof (l->fns) / sizeof (l->fns[0])) {
       i = l->idx++;
       break;
     }
   }
   if (l == NULL) {
     l = (struct exit_function_list *)malloc( sizeof(struct exit_function_list) );
     if (l != NULL) {
       l->next = __exit_funcs;
       __exit_funcs = l;
       l->idx = 1;
       i = 0;
     }
   }
   /* Mark entry as used, but we don't know the flavor now.  */
   if ( l != NULL )
     l->fns[i].flavor = ef_us;
 #ifndef __FreeBSD__
   pthread_mutex_unlock( &lock );
 #endif
   return l == NULL ? NULL : &l->fns[i];
 }
 /* If D is non-NULL, call all functions registered with `__cxa_atexit'
    with the same dso handle.  Otherwise, if D is NULL, call all of the
    registered handlers.  */
 /*
  * Note, that original __cxa_finalize don't use lock, but use __exit_funcs
  * i.e. global data.
  */
 void __cxa_finalize(void *d)
 {
   struct exit_function_list *funcs;
 #ifndef __FreeBSD__
   pthread_mutex_lock( &lock );
 #endif
   for (funcs = __exit_funcs; funcs; funcs = funcs->next) {
     struct exit_function *f;
     for (f = &funcs->fns[funcs->idx - 1]; f >= &funcs->fns[0]; --f) {
       if ( (d == NULL || d == f->func.cxa.dso_handle) && (f->flavor == ef_cxa) ) {
         f->flavor = ef_free;
         (*f->func.cxa.fn) (f->func.cxa.arg, 0);
       }
     }
   }
   /* Remove the registered fork handlers.  We do not have to
      unregister anything if the program is going to terminate anyway.  */
 #ifdef UNREGISTER_ATFORK
   if (d != NULL)
     UNREGISTER_ATFORK (d);
 #endif
 #ifndef __FreeBSD__
   pthread_mutex_unlock( &lock );
 #endif
 }
 /* __asm__ (".symver " "__cxa_finalize" "," "__cxa_finalize" "@@" "STLPORT_5_0_0"); */
 /* void __cxa_finalize(void *d) __attribute__ ((weak)); */
 #endif /* OS name */
 #endif /* __unix */

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