pdns/mtasker_context.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23 #include "lazy_allocator.hh"
  24 #include <boost/function.hpp>
  25 #include <vector>
  26 #include <exception>
  27
  28 struct pdns_ucontext_t {
  29     pdns_ucontext_t ();
  30     pdns_ucontext_t (pdns_ucontext_t const&) = delete;
  31     pdns_ucontext_t& operator= (pdns_ucontext_t const&) = delete;
  32     ~pdns_ucontext_t ();
  33
  34     void* uc_mcontext;
  35     pdns_ucontext_t* uc_link;
  36     std::vector<char, lazy_allocator<char>> uc_stack;
  37     std::exception_ptr exception;
  38 #ifdef PDNS_USE_VALGRIND
  39     int valgrind_id;
  40 #endif /* PDNS_USE_VALGRIND */
  41 };
  42
  43 void
  44 pdns_swapcontext
  45 (pdns_ucontext_t& __restrict octx, pdns_ucontext_t const& __restrict ctx);
  46
  47 void
  48 pdns_makecontext
  49 (pdns_ucontext_t& ctx, boost::function<void(void)>& start);
  50
  51 #ifdef HAVE_FIBER_SANITIZER
  52 #include <sanitizer/common_interface_defs.h>
  53 #endif /* HAVE_FIBER_SANITIZER */
  54
  55 #ifdef HAVE_FIBER_SANITIZER
  56 extern __thread void* t_mainStack;
  57 extern __thread size_t t_mainStackSize;
  58 #endif /* HAVE_FIBER_SANITIZER */
  59
  60 static inline void notifyStackSwitch(void* startOfStack, size_t stackSize)
  61 {
  62 #ifdef HAVE_FIBER_SANITIZER
  63   __sanitizer_start_switch_fiber(nullptr, startOfStack, stackSize);
  64 #endif /* HAVE_FIBER_SANITIZER */
  65 }
  66
  67 static inline void notifyStackSwitchToKernel()
  68 {
  69 #ifdef HAVE_FIBER_SANITIZER
  70   notifyStackSwitch(t_mainStack, t_mainStackSize);
  71 #endif /* HAVE_FIBER_SANITIZER */
  72 }
  73
  74 static inline void notifyStackSwitchDone()
  75 {
  76 #ifdef HAVE_FIBER_SANITIZER
  77 #ifdef HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR
  78   __sanitizer_finish_switch_fiber(nullptr);
  79 #else /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR */
  80 #ifdef HAVE_SANITIZER_FINISH_SWITCH_FIBER_THREE_PTRS
  81   __sanitizer_finish_switch_fiber(nullptr, nullptr, nullptr);
  82 #endif /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_THREE_PTRS */
  83 #endif /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR */
  84 #endif /* HAVE_FIBER_SANITIZER */
  85 }