-/* Copyright (c) 2009-2017. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2009-2019. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
/* \file UContext.cpp Context switching with ucontexts from System V */
-#include "ContextUnix.hpp"
+#include "context_private.hpp"
#include "mc/mc.h"
-#include "src/mc/mc_ignore.h"
-#include "src/simix/ActorImpl.hpp"
+#include "simgrid/Exception.hpp"
+#include "src/kernel/actor/ActorImpl.hpp"
+#include "src/mc/mc_ignore.hpp"
+#include "src/simix/smx_private.hpp"
+
+#include "ContextUnix.hpp"
XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
-/** Many integers are needed to store a pointer
- *
- * Support up to two ints. */
+/** Up to two integers may be needed to store a pointer on the system we target */
constexpr int CTX_ADDR_LEN = 2;
static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int),
- "Ucontexts are not supported on this arch yet");
+ "Ucontexts are not supported on this arch yet. Please increase CTX_ADDR_LEN.");
+
+/* Make sure that this symbol is easy to recognize by name, even on exotic platforms */
+extern "C" {
+static void smx_ctx_wrapper(int i1, int i2);
+}
-// The name of this function is currently hardcoded in the code (as string).
+// The name of this function is currently hardcoded in MC (as string).
// Do not change it without fixing those references as well.
-static void smx_ctx_sysv_wrapper(int i1, int i2)
+static void smx_ctx_wrapper(int i1, int i2)
{
// Rebuild the Context* pointer from the integers:
int ctx_addr[CTX_ADDR_LEN] = {i1, i2};
simgrid::kernel::context::UContext* context;
memcpy(&context, ctx_addr, sizeof context);
+ ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_);
try {
(*context)();
context->Context::stop();
- } catch (simgrid::kernel::context::Context::StopRequest const&) {
- XBT_DEBUG("Caught a StopRequest");
+ } catch (simgrid::ForcefulKillException const&) {
+ XBT_DEBUG("Caught a ForcefulKillException");
+ } catch (simgrid::Exception const& e) {
+ XBT_INFO("Actor killed by an uncaught exception %s", simgrid::xbt::demangle(typeid(e).name()).get());
+ throw;
}
+ ASAN_ONLY(context->asan_stop_ = true);
context->suspend();
}
namespace context {
// UContextFactory
-
-UContextFactory::UContextFactory() : ContextFactory("UContextFactory"), parallel_(SIMIX_context_is_parallel())
+UContext* UContextFactory::create_context(std::function<void()>&& code, actor::ActorImpl* actor)
{
- UContext::setMaestro(nullptr);
- if (parallel_) {
-#if HAVE_THREAD_CONTEXTS
- ParallelUContext::initialize();
-#else
- xbt_die("No thread support for parallel context execution");
-#endif
- }
+ return new_context<UContext>(std::move(code), actor, this);
}
-UContextFactory::~UContextFactory()
-{
-#if HAVE_THREAD_CONTEXTS
- if (parallel_)
- ParallelUContext::finalize();
-#endif
-}
-
-Context* UContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup, smx_actor_t process)
-{
-#if HAVE_THREAD_CONTEXTS
- if (parallel_)
- return new_context<ParallelUContext>(std::move(code), cleanup, process);
- else
-#endif
- return new_context<SerialUContext>(std::move(code), cleanup, process);
-}
-
-/* This function is called by maestro at the beginning of a scheduling round to get all working threads executing some
- * stuff It is much easier to understand what happens if you see the working threads as bodies that swap their soul for
- * the ones of the simulated processes that must run.
- */
-void UContextFactory::run_all()
-{
-#if HAVE_THREAD_CONTEXTS
- if (parallel_)
- ParallelUContext::run_all();
- else
-#endif
- SerialUContext::run_all();
-}
// UContext
-UContext* UContext::maestro_context_ = nullptr;
-
-UContext::UContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process)
- : Context(std::move(code), cleanup_func, process)
+UContext::UContext(std::function<void()>&& code, actor::ActorImpl* actor, SwappedContextFactory* factory)
+ : SwappedContext(std::move(code), actor, factory)
{
- /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
+ /* if the user provided a function for the actor then use it. If not, nothing to do for maestro. */
if (has_code()) {
- this->stack_ = SIMIX_context_stack_new();
getcontext(&this->uc_);
this->uc_.uc_link = nullptr;
- this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(this->stack_);
- this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_usable_stack_size);
- UContext::make_ctx(&this->uc_, UContext::wrapper, this);
- } else {
- if (process != nullptr && maestro_context_ == nullptr)
- maestro_context_ = this;
- }
+ this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(get_stack());
+ this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_stack_size);
+ // Makecontext expects integer arguments; we want to pass a pointer.
+ // This context address is decomposed into a serie of integers, which are passed as arguments to makecontext.
+
+ int ctx_addr[CTX_ADDR_LEN]{};
+ UContext* arg = this;
+ memcpy(ctx_addr, &arg, sizeof this);
+ makecontext(&this->uc_, (void (*)())smx_ctx_wrapper, 2, ctx_addr[0], ctx_addr[1]);
#if SIMGRID_HAVE_MC
- if (MC_is_active() && has_code()) {
- MC_register_stack_area(this->stack_, process, &(this->uc_), smx_context_usable_stack_size);
- }
+ if (MC_is_active()) {
+ MC_register_stack_area(get_stack(), actor, &(this->uc_), smx_context_stack_size);
+ }
#endif
-}
-
-UContext::~UContext()
-{
- SIMIX_context_stack_delete(this->stack_);
-}
-
-void UContext::wrapper(int i1, int i2)
-{
- smx_ctx_sysv_wrapper(i1, i2);
-}
-
-/** A better makecontext
- *
- * Makecontext expects integer arguments, we the context variable is decomposed into a serie of integers and each
- * integer is passed as argument to makecontext.
- */
-void UContext::make_ctx(ucontext_t* ucp, void (*func)(int, int), UContext* arg)
-{
- int ctx_addr[CTX_ADDR_LEN]{};
- memcpy(ctx_addr, &arg, sizeof arg);
- makecontext(ucp, (void (*)())func, 2, ctx_addr[0], ctx_addr[1]);
-}
-
-void UContext::stop()
-{
- Context::stop();
- throw StopRequest();
-}
-
-// SerialUContext
-
-unsigned long SerialUContext::process_index_; /* index of the next process to run in the list of runnable processes */
-
-void SerialUContext::suspend()
-{
- /* determine the next context */
- SerialUContext* next_context;
- unsigned long int i = process_index_;
- process_index_++;
-
- if (i < simix_global->process_to_run.size()) {
- /* execute the next process */
- XBT_DEBUG("Run next process");
- next_context = static_cast<SerialUContext*>(simix_global->process_to_run[i]->context);
- } else {
- /* all processes were run, return to maestro */
- XBT_DEBUG("No more process to run");
- next_context = static_cast<SerialUContext*>(UContext::getMaestro());
}
- SIMIX_context_set_current(next_context);
- UContext::swap(this, next_context);
}
-void SerialUContext::resume()
+void UContext::swap_into(SwappedContext* to_)
{
- SIMIX_context_set_current(this);
- UContext::swap(UContext::getMaestro(), this);
+ UContext* to = static_cast<UContext*>(to_);
+ ASAN_ONLY(void* fake_stack = nullptr);
+ ASAN_ONLY(to->asan_ctx_ = this);
+ ASAN_START_SWITCH(this->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
+ swapcontext(&this->uc_, &to->uc_);
+ ASAN_FINISH_SWITCH(fake_stack, &this->asan_ctx_->asan_stack_, &this->asan_ctx_->asan_stack_size_);
}
-void SerialUContext::run_all()
-{
- if (simix_global->process_to_run.empty())
- return;
- smx_actor_t first_process = simix_global->process_to_run.front();
- process_index_ = 1;
- static_cast<SerialUContext*>(first_process->context)->resume();
-}
-
-// ParallelUContext
-
-#if HAVE_THREAD_CONTEXTS
-
-simgrid::xbt::Parmap<smx_actor_t>* ParallelUContext::parmap_;
-std::atomic<uintptr_t> ParallelUContext::threads_working_; /* number of threads that have started their work */
-xbt_os_thread_key_t ParallelUContext::worker_id_key_; /* thread-specific storage for the thread id */
-std::vector<ParallelUContext*> ParallelUContext::workers_context_; /* space to save the worker's context
- * in each thread */
-
-void ParallelUContext::initialize()
-{
- parmap_ = nullptr;
- workers_context_.clear();
- workers_context_.resize(SIMIX_context_get_nthreads(), nullptr);
- xbt_os_thread_key_create(&worker_id_key_);
-}
-
-void ParallelUContext::finalize()
-{
- delete parmap_;
- parmap_ = nullptr;
- workers_context_.clear();
- xbt_os_thread_key_destroy(worker_id_key_);
-}
-
-void ParallelUContext::run_all()
-{
- threads_working_ = 0;
- // Parmap_apply ensures that every working thread get an index in the process_to_run array (through an atomic
- // fetch_and_add), and runs the ParallelUContext::resume function on that index
-
- // We lazily create the parmap because the parmap creates context with simix_global->context_factory (which might not
- // be initialized when bootstrapping):
- if (parmap_ == nullptr)
- parmap_ = new simgrid::xbt::Parmap<smx_actor_t>(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode());
- parmap_->apply(
- [](smx_actor_t process) {
- ParallelUContext* context = static_cast<ParallelUContext*>(process->context);
- context->resume();
- },
- simix_global->process_to_run);
-}
-
-/** Yield
- *
- * This function is called when a simulated process wants to yield back to the maestro in a blocking simcall. This
- * naturally occurs within SIMIX_context_suspend(self->context), called from SIMIX_process_yield() Actually, it does not
- * really yield back to maestro, but into the next process that must be executed. If no one is to be executed, then it
- * yields to the initial soul that was in this working thread (that was saved in resume_parallel).
- */
-void ParallelUContext::suspend()
-{
- /* determine the next context */
- // Get the next soul to embody now:
- boost::optional<smx_actor_t> next_work = parmap_->next();
- ParallelUContext* next_context;
- if (next_work) {
- // There is a next soul to embody (ie, a next process to resume)
- XBT_DEBUG("Run next process");
- next_context = static_cast<ParallelUContext*>(next_work.get()->context);
- } else {
- // All processes were run, go to the barrier
- XBT_DEBUG("No more processes to run");
- // Get back the identity of my body that was stored when starting the scheduling round
- uintptr_t worker_id = reinterpret_cast<uintptr_t>(xbt_os_thread_get_specific(worker_id_key_));
- // Deduce the initial soul of that body
- next_context = workers_context_[worker_id];
- // When given that soul, the body will wait for the next scheduling round
- }
-
- SIMIX_context_set_current(next_context);
- // Get the next soul to run, either simulated or initial minion's one:
- UContext::swap(this, next_context);
-}
-
-/** Run one particular simulated process on the current thread. */
-void ParallelUContext::resume()
-{
- // What is my containing body?
- uintptr_t worker_id = threads_working_.fetch_add(1, std::memory_order_relaxed);
- // Store the number of my containing body in os-thread-specific area :
- xbt_os_thread_set_specific(worker_id_key_, reinterpret_cast<void*>(worker_id));
- // Get my current soul:
- ParallelUContext* worker_context = static_cast<ParallelUContext*>(SIMIX_context_self());
- // Write down that this soul is hosted in that body (for now)
- workers_context_[worker_id] = worker_context;
- // Write in simix that I switched my soul
- SIMIX_context_set_current(this);
- // Actually do that using the relevant library call:
- UContext::swap(worker_context, this);
- // No body runs that soul anymore at this point. Instead the current body took the soul of simulated process The
- // simulated process wakes back after the call to "SIMIX_context_suspend(self->context);" within
- // smx_process.c::SIMIX_process_yield()
-
- // From now on, the simulated processes will change their soul with the next soul to execute (in suspend_parallel,
- // below). When nobody is to be executed in this scheduling round, the last simulated process will take back the
- // initial soul of the current working thread
-}
-
-#endif
XBT_PRIVATE ContextFactory* sysv_factory()
{
XBT_VERB("Activating SYSV context factory");
return new UContextFactory();
}
-}}} // namespace simgrid::kernel::context
+} // namespace context
+} // namespace kernel
+} // namespace simgrid
