src/sthread/ObjectAccess.cpp

   1 /* Copyright (c) 2002-2023. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 /* Object access checker, for use in sthread. */
   7
   8 #include "simgrid/modelchecker.h"
   9 #include "simgrid/s4u/Actor.hpp"
  10 #include "simgrid/simix.hpp"
  11 #include "src/kernel/actor/ActorImpl.hpp"
  12 #include "src/kernel/actor/SimcallObserver.hpp"
  13 #include "src/sthread/sthread.h"
  14 #include "xbt/string.hpp"
  15
  16 #include <unordered_map>
  17
  18 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(sthread);
  19
  20 namespace simgrid::sthread {
  21 XBT_DECLARE_ENUM_CLASS(AccessType, ENTER, EXIT, BOTH);
  22
  23 class ObjectAccessObserver final : public simgrid::kernel::actor::SimcallObserver {
  24   AccessType type_;
  25   void* objaddr_;
  26   const char* objname_;
  27   const char* file_;
  28   int line_;
  29
  30 public:
  31   ObjectAccessObserver(simgrid::kernel::actor::ActorImpl* actor, AccessType type, void* objaddr, const char* objname,
  32                        const char* file, int line)
  33       : SimcallObserver(actor), type_(type), objaddr_(objaddr), objname_(objname), file_(file), line_(line)
  34   {
  35   }
  36   void serialize(std::stringstream& stream) const override;
  37   std::string to_string() const override;
  38 };
  39 void ObjectAccessObserver::serialize(std::stringstream& stream) const
  40 {
  41   stream << (short)mc::Transition::Type::OBJECT_ACCESS << ' ';
  42   stream << (short)type_ << ' ' << objaddr_ << ' ' << objname_ << ' ' << file_ << ' ' << line_;
  43 }
  44 std::string ObjectAccessObserver::to_string() const
  45 {
  46   return std::string("AccessObject(") + objname_ + ")";
  47 }
  48 }; // namespace simgrid::sthread
  49
  50 struct ObjectOwner {
  51   simgrid::kernel::actor::ActorImpl* owner = nullptr;
  52   const char* file                         = nullptr;
  53   int line                                 = -1;
  54   explicit ObjectOwner(simgrid::kernel::actor::ActorImpl* o) : owner(o) {}
  55 };
  56
  57 std::unordered_map<void*, ObjectOwner*> owners;
  58 static void clean_owners()
  59 {
  60   for (auto it = owners.begin(); it != owners.end();) {
  61     delete it->second;
  62     it = owners.erase(it);
  63   }
  64 }
  65 static ObjectOwner* get_owner(void* object)
  66 {
  67   if (owners.empty())
  68     std::atexit(clean_owners);
  69   if (auto it = owners.find(object); it != owners.end())
  70     return it->second;
  71   auto* o = new ObjectOwner(nullptr);
  72   owners.emplace(object, o);
  73   return o;
  74 }
  75
  76 int sthread_access_begin(void* objaddr, const char* objname, const char* file, int line)
  77 {
  78   sthread_disable();
  79   auto* self = simgrid::kernel::actor::ActorImpl::self();
  80   simgrid::sthread::ObjectAccessObserver observer(self, simgrid::sthread::AccessType::ENTER, objaddr, objname, file,
  81                                                   line);
  82   bool success = simgrid::kernel::actor::simcall_answered(
  83       [self, objaddr, objname, file, line]() -> bool {
  84         XBT_INFO("%s takes %s", self->get_cname(), objname);
  85         auto* ownership = get_owner(objaddr);
  86         if (ownership->owner != nullptr) {
  87           auto msg = std::string("Unprotected concurent access to ") + objname + ": " + ownership->owner->get_name();
  88           if (not xbt_log_no_loc)
  89             msg += simgrid::xbt::string_printf(" at %s:%d", ownership->file, ownership->line);
  90           msg += " vs " + self->get_name();
  91           if (xbt_log_no_loc)
  92             msg += std::string(" (locations hidden because of --log=no_loc).");
  93           else
  94             msg += simgrid::xbt::string_printf(" at %s:%d.", file, line);
  95           XBT_CRITICAL("%s", msg.c_str());
  96           return false;
  97         }
  98         ownership->owner = self;
  99         ownership->file  = file;
 100         ownership->line  = line;
 101         return true;
 102       },
 103       &observer);
 104   MC_assert(success);
 105   xbt_assert(success, "Problem detected, bailing out");
 106   sthread_enable();
 107   return true;
 108 }
 109 void sthread_access_end(void* objaddr, const char* objname, const char* file, int line)
 110 {
 111   sthread_disable();
 112   auto* self = simgrid::kernel::actor::ActorImpl::self();
 113   simgrid::sthread::ObjectAccessObserver observer(self, simgrid::sthread::AccessType::EXIT, objaddr, objname, file,
 114                                                   line);
 115   simgrid::kernel::actor::simcall_answered(
 116       [self, objaddr, objname]() -> void {
 117         XBT_INFO("%s releases %s", self->get_cname(), objname);
 118         auto* ownership = get_owner(objaddr);
 119         xbt_assert(ownership->owner == self, "safety check failed: %s is not owner of the object it's releasing.",
 120                    self->get_cname());
 121         ownership->owner = nullptr;
 122       },
 123       &observer);
 124   sthread_enable();
 125 }