linuxthreads/ptlongjmp.c

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1998 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program is distributed in the hope that it will be useful,      */
  11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 /* Redefine siglongjmp and longjmp so that they interact correctly
  16    with cleanup handlers */
  17
  18 #include <setjmp.h>
  19 #include "pthread.h"
  20 #include "internals.h"
  21
  22 /* These functions are not declared anywhere since they shouldn't be
  23    used at another place but here.  */
  24 extern void __libc_siglongjmp (sigjmp_buf env, int val)
  25      __attribute__ ((noreturn));
  26 extern void __libc_longjmp (sigjmp_buf env, int val)
  27      __attribute__ ((noreturn));
  28
  29
  30 static void pthread_cleanup_upto(__jmp_buf target)
  31 {
  32   pthread_descr self = thread_self();
  33   struct _pthread_cleanup_buffer * c;
  34   char *currentframe = CURRENT_STACK_FRAME;
  35
  36   for (c = THREAD_GETMEM(self, p_cleanup);
  37        c != NULL && _JMPBUF_UNWINDS(target, c);
  38        c = c->__prev)
  39     {
  40 #if _STACK_GROWS_DOWN
  41       if ((char *) c <= currentframe)
  42         {
  43           c = NULL;
  44           break;
  45         }
  46 #elif _STACK_GROWS_UP
  47       if ((char *) c >= currentframe)
  48         {
  49           c = NULL;
  50           break;
  51         }
  52 #else
  53 # error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
  54 #endif
  55       c->__routine(c->__arg);
  56     }
  57   THREAD_SETMEM(self, p_cleanup, c);
  58   if (THREAD_GETMEM(self, p_in_sighandler)
  59       && _JMPBUF_UNWINDS(target, THREAD_GETMEM(self, p_in_sighandler)))
  60     THREAD_SETMEM(self, p_in_sighandler, NULL);
  61 }
  62
  63 void siglongjmp(sigjmp_buf env, int val)
  64 {
  65   pthread_cleanup_upto(env->__jmpbuf);
  66   __libc_siglongjmp(env, val);
  67 }
  68
  69 void longjmp(jmp_buf env, int val)
  70 {
  71   pthread_cleanup_upto(env->__jmpbuf);
  72   __libc_longjmp(env, val);
  73 }