1 /* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved. */
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. */
6 #include "simgrid/modelchecker.h"
7 #include "src/internal_config.h"
8 #include "src/kernel/context/context_private.hpp"
9 #include "src/simix/ActorImpl.hpp"
10 #include "src/simix/smx_private.hpp"
12 #include "src/kernel/context/ContextSwapped.hpp"
22 #define _aligned_malloc __mingw_aligned_malloc
23 #define _aligned_free __mingw_aligned_free
27 #include <valgrind/valgrind.h>
30 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
36 unsigned long SwappedContext::process_index_;
38 SwappedContext* SwappedContext::maestro_context_ = nullptr;
40 SwappedContext::SwappedContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
41 : Context(std::move(code), cleanup_func, process)
44 if (smx_context_guard_size > 0 && not MC_is_active()) {
46 #if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1)
48 "Stack overflow protection is known to be broken on your system: you stacks grow upwards (or detection is "
50 "Please disable stack guards with --cfg=contexts:guard-size:0");
51 /* Current code for stack overflow protection assumes that stacks are growing downward (PTH_STACKGROWTH == -1).
52 * Protected pages need to be put after the stack when PTH_STACKGROWTH == 1. */
55 size_t size = smx_context_stack_size + smx_context_guard_size;
57 /* Cannot use posix_memalign when SIMGRID_HAVE_MC. Align stack by hand, and save the
58 * pointer returned by xbt_malloc0. */
59 char* alloc = (char*)xbt_malloc0(size + xbt_pagesize);
60 stack_ = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize;
61 *((void**)stack_ - 1) = alloc;
62 #elif !defined(_WIN32)
63 if (posix_memalign(&this->stack_, xbt_pagesize, size) != 0)
64 xbt_die("Failed to allocate stack.");
66 this->stack_ = _aligned_malloc(size, xbt_pagesize);
70 if (mprotect(this->stack_, smx_context_guard_size, PROT_NONE) == -1) {
72 "Failed to protect stack: %s.\n"
73 "If you are running a lot of actors, you may be exceeding the amount of mappings allowed per process.\n"
74 "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n"
75 "Please see http://simgrid.gforge.inria.fr/simgrid/latest/doc/html/options.html#options_virt for more "
78 /* This is fatal. We are going to fail at some point when we try reusing this. */
81 this->stack_ = (char*)this->stack_ + smx_context_guard_size;
83 this->stack_ = xbt_malloc0(smx_context_stack_size);
87 unsigned int valgrind_stack_id =
88 VALGRIND_STACK_REGISTER(this->stack_, (char*)this->stack_ + smx_context_stack_size);
89 memcpy((char*)this->stack_ + smx_context_usable_stack_size, &valgrind_stack_id, sizeof valgrind_stack_id);
94 SwappedContext::~SwappedContext()
96 if (stack_ == nullptr)
100 unsigned int valgrind_stack_id;
101 memcpy(&valgrind_stack_id, (char*)stack_ + smx_context_usable_stack_size, sizeof valgrind_stack_id);
102 VALGRIND_STACK_DEREGISTER(valgrind_stack_id);
106 if (smx_context_guard_size > 0 && not MC_is_active()) {
107 stack_ = (char*)stack_ - smx_context_guard_size;
108 if (mprotect(stack_, smx_context_guard_size, PROT_READ | PROT_WRITE) == -1) {
109 XBT_WARN("Failed to remove page protection: %s", strerror(errno));
110 /* try to pursue anyway */
113 /* Retrieve the saved pointer. See SIMIX_context_stack_new above. */
114 stack_ = *((void**)stack_ - 1);
117 #endif /* not windows */
122 void SwappedContext::suspend()
124 /* determine the next context */
125 SwappedContext* next_context;
126 unsigned long int i = process_index_;
129 if (i < simix_global->process_to_run.size()) {
130 /* execute the next process */
131 XBT_DEBUG("Run next process");
132 next_context = static_cast<SwappedContext*>(simix_global->process_to_run[i]->context_);
134 /* all processes were run, return to maestro */
135 XBT_DEBUG("No more process to run");
136 next_context = static_cast<SwappedContext*>(get_maestro());
138 Context::set_current(next_context);
139 this->swap_into(next_context);
142 void SwappedContext::resume()
144 SwappedContext* old = static_cast<SwappedContext*>(self());
145 Context::set_current(this);
146 old->swap_into(this);
149 void SwappedContext::run_all()
151 if (simix_global->process_to_run.empty())
153 smx_actor_t first_process = simix_global->process_to_run.front();
155 /* execute the first process */
156 static_cast<SwappedContext*>(first_process->context_)->resume();
158 } // namespace context
159 } // namespace kernel
160 } // namespace simgrid