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 #ifndef MTASKER_CONTEXT_HH
  23 #define MTASKER_CONTEXT_HH
  24
  25 #include "lazy_allocator.hh"
  26 #include <boost/function.hpp>
  27 #include <vector>
  28 #include <exception>
  29
  30 struct pdns_ucontext_t {
  31     pdns_ucontext_t ();
  32     pdns_ucontext_t (pdns_ucontext_t const&) = delete;
  33     pdns_ucontext_t& operator= (pdns_ucontext_t const&) = delete;
  34     ~pdns_ucontext_t ();
  35
  36     void* uc_mcontext;
  37     pdns_ucontext_t* uc_link;
  38     std::vector<char, lazy_allocator<char>> uc_stack;
  39     std::exception_ptr exception;
  40 #ifdef PDNS_USE_VALGRIND
  41     int valgrind_id;
  42 #endif /* PDNS_USE_VALGRIND */
  43 };
  44
  45 void
  46 pdns_swapcontext
  47 (pdns_ucontext_t& __restrict octx, pdns_ucontext_t const& __restrict ctx);
  48
  49 void
  50 pdns_makecontext
  51 (pdns_ucontext_t& ctx, boost::function<void(void)>& start);
  52
  53 #ifdef HAVE_FIBER_SANITIZER
  54 #include <sanitizer/common_interface_defs.h>
  55 #endif /* HAVE_FIBER_SANITIZER */
  56
  57 #ifdef HAVE_FIBER_SANITIZER
  58 extern __thread void* t_mainStack;
  59 extern __thread size_t t_mainStackSize;
  60 #endif /* HAVE_FIBER_SANITIZER */
  61
  62 static inline void notifyStackSwitch(void* startOfStack, size_t stackSize)
  63 {
  64 #ifdef HAVE_FIBER_SANITIZER
  65   __sanitizer_start_switch_fiber(nullptr, startOfStack, stackSize);
  66 #endif /* HAVE_FIBER_SANITIZER */
  67 }
  68
  69 static inline void notifyStackSwitchToKernel()
  70 {
  71 #ifdef HAVE_FIBER_SANITIZER
  72   notifyStackSwitch(t_mainStack, t_mainStackSize);
  73 #endif /* HAVE_FIBER_SANITIZER */
  74 }
  75
  76 static inline void notifyStackSwitchDone()
  77 {
  78 #ifdef HAVE_FIBER_SANITIZER
  79 #ifdef HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR
  80   __sanitizer_finish_switch_fiber(nullptr);
  81 #else /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR */
  82 #ifdef HAVE_SANITIZER_FINISH_SWITCH_FIBER_THREE_PTRS
  83   __sanitizer_finish_switch_fiber(nullptr, nullptr, nullptr);
  84 #endif /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_THREE_PTRS */
  85 #endif /* HAVE_SANITIZER_FINISH_SWITCH_FIBER_SINGLE_PTR */
  86 #endif /* HAVE_FIBER_SANITIZER */
  87 }
  88
  89
  90 #endif // MTASKER_CONTEXT_HH