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"
11 #include "xbt/parmap.hpp"
13 #include "src/kernel/context/ContextSwapped.hpp"
23 #define _aligned_malloc __mingw_aligned_malloc
24 #define _aligned_free __mingw_aligned_free
28 #include <valgrind/valgrind.h>
31 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
37 /* Sequential execution */
38 unsigned long SwappedContext::process_index_;
40 /* Parallel execution */
41 simgrid::xbt::Parmap<smx_actor_t>* SwappedContext::parmap_;
42 std::atomic<uintptr_t> SwappedContext::threads_working_; /* number of threads that have started their work */
43 thread_local uintptr_t SwappedContext::worker_id_; /* thread-specific storage for the thread id */
44 std::vector<SwappedContext*> SwappedContext::workers_context_; /* space to save the worker's context in each thread */
46 void SwappedContext::initialize()
49 workers_context_.clear();
50 workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
53 void SwappedContext::finalize()
57 workers_context_.clear();
60 SwappedContext* SwappedContext::maestro_context_ = nullptr;
62 SwappedContext::SwappedContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
63 : Context(std::move(code), cleanup_func, process)
66 if (smx_context_guard_size > 0 && not MC_is_active()) {
68 #if !defined(PTH_STACKGROWTH) || (PTH_STACKGROWTH != -1)
70 "Stack overflow protection is known to be broken on your system: you stacks grow upwards (or detection is "
72 "Please disable stack guards with --cfg=contexts:guard-size:0");
73 /* Current code for stack overflow protection assumes that stacks are growing downward (PTH_STACKGROWTH == -1).
74 * Protected pages need to be put after the stack when PTH_STACKGROWTH == 1. */
77 size_t size = smx_context_stack_size + smx_context_guard_size;
79 /* Cannot use posix_memalign when SIMGRID_HAVE_MC. Align stack by hand, and save the
80 * pointer returned by xbt_malloc0. */
81 char* alloc = (char*)xbt_malloc0(size + xbt_pagesize);
82 stack_ = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize;
83 *((void**)stack_ - 1) = alloc;
84 #elif !defined(_WIN32)
85 if (posix_memalign(&this->stack_, xbt_pagesize, size) != 0)
86 xbt_die("Failed to allocate stack.");
88 this->stack_ = _aligned_malloc(size, xbt_pagesize);
92 if (mprotect(this->stack_, smx_context_guard_size, PROT_NONE) == -1) {
94 "Failed to protect stack: %s.\n"
95 "If you are running a lot of actors, you may be exceeding the amount of mappings allowed per process.\n"
96 "On Linux systems, change this value with sudo sysctl -w vm.max_map_count=newvalue (default value: 65536)\n"
97 "Please see http://simgrid.gforge.inria.fr/simgrid/latest/doc/html/options.html#options_virt for more "
100 /* This is fatal. We are going to fail at some point when we try reusing this. */
103 this->stack_ = (char*)this->stack_ + smx_context_guard_size;
105 this->stack_ = xbt_malloc0(smx_context_stack_size);
109 unsigned int valgrind_stack_id =
110 VALGRIND_STACK_REGISTER(this->stack_, (char*)this->stack_ + smx_context_stack_size);
111 memcpy((char*)this->stack_ + smx_context_usable_stack_size, &valgrind_stack_id, sizeof valgrind_stack_id);
116 SwappedContext::~SwappedContext()
118 if (stack_ == nullptr)
122 unsigned int valgrind_stack_id;
123 memcpy(&valgrind_stack_id, (char*)stack_ + smx_context_usable_stack_size, sizeof valgrind_stack_id);
124 VALGRIND_STACK_DEREGISTER(valgrind_stack_id);
128 if (smx_context_guard_size > 0 && not MC_is_active()) {
129 stack_ = (char*)stack_ - smx_context_guard_size;
130 if (mprotect(stack_, smx_context_guard_size, PROT_READ | PROT_WRITE) == -1) {
131 XBT_WARN("Failed to remove page protection: %s", strerror(errno));
132 /* try to pursue anyway */
135 /* Retrieve the saved pointer. See SIMIX_context_stack_new above. */
136 stack_ = *((void**)stack_ - 1);
139 #endif /* not windows */
144 /** Maestro wants to run all read_to_run actors */
145 void SwappedContext::run_all()
147 if (simix_global->process_to_run.empty())
149 smx_actor_t first_process = simix_global->process_to_run.front();
151 /* execute the first process */
152 static_cast<SwappedContext*>(first_process->context_)->resume();
155 /** Maestro wants to yield back to a given actor */
156 void SwappedContext::resume()
158 // Maestro is always the calling thread of this function (ie, self() == maestro)
159 SwappedContext* old = static_cast<SwappedContext*>(self());
160 Context::set_current(this);
161 old->swap_into(this);
164 /** The actor wants to yield back to maestro */
165 void SwappedContext::suspend()
167 /* determine the next context */
168 SwappedContext* next_context;
169 unsigned long int i = process_index_;
172 if (i < simix_global->process_to_run.size()) {
173 /* Actually swap into the next actor directly without transiting to maestro */
174 XBT_DEBUG("Run next process");
175 next_context = static_cast<SwappedContext*>(simix_global->process_to_run[i]->context_);
177 /* all processes were run, actually return to maestro */
178 XBT_DEBUG("No more process to run");
179 next_context = static_cast<SwappedContext*>(get_maestro());
181 Context::set_current(next_context);
182 this->swap_into(next_context);
185 } // namespace context
186 } // namespace kernel
187 } // namespace simgrid