X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/e4bdd31e7ef80a47732508c06ef157692be13f94..b9945098e2ba4e7b639e0c2245835d44800c1b29:/src/kernel/context/ContextUnix.cpp diff --git a/src/kernel/context/ContextUnix.cpp b/src/kernel/context/ContextUnix.cpp index f7df3680b1..70a87d20ca 100644 --- a/src/kernel/context/ContextUnix.cpp +++ b/src/kernel/context/ContextUnix.cpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2009-2018. 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. */ @@ -9,95 +9,28 @@ #include "mc/mc.h" #include "simgrid/Exception.hpp" +#include "src/kernel/actor/ActorImpl.hpp" #include "src/mc/mc_ignore.hpp" -#include "src/simix/ActorImpl.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."); -namespace simgrid { -namespace kernel { -namespace context { - -// UContextFactory - -UContextFactory::UContextFactory() : ContextFactory("UContextFactory"), parallel_(SIMIX_context_is_parallel()) -{ - UContext::set_maestro(nullptr); - if (parallel_) - SwappedContext::initialize(); -} - -UContextFactory::~UContextFactory() -{ - if (parallel_) - SwappedContext::finalize(); -} - -Context* UContextFactory::create_context(std::function code, void_pfn_smxprocess_t cleanup, smx_actor_t process) -{ - if (parallel_) - return new_context(std::move(code), cleanup, process); - else - return new_context(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 (parallel_) - ParallelUContext::run_all(); - else - SwappedContext::run_all(); -} - -// UContext - -UContext::UContext(std::function code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : SwappedContext(std::move(code), cleanup_func, process) -{ - /* if the user provided a function for the process then use it, otherwise it is the context for maestro */ - if (has_code()) { - 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); -#if PTH_STACKGROWTH == -1 - ASAN_ONLY(this->asan_stack_ = static_cast(this->stack_) + smx_context_usable_stack_size); -#else - ASAN_ONLY(this->asan_stack_ = this->stack_); -#endif - UContext::make_ctx(&this->uc_, UContext::smx_ctx_sysv_wrapper, this); - } else { - if (process != nullptr && get_maestro() == nullptr) - set_maestro(this); - } - -#if SIMGRID_HAVE_MC - if (MC_is_active() && has_code()) { - MC_register_stack_area(this->stack_, process, &(this->uc_), smx_context_usable_stack_size); - } -#endif +/* 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); } -UContext::~UContext() = default; - -// 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. -void UContext::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}; @@ -107,121 +40,66 @@ void UContext::smx_ctx_sysv_wrapper(int i1, int i2) ASAN_FINISH_SWITCH(nullptr, &context->asan_ctx_->asan_stack_, &context->asan_ctx_->asan_stack_size_); try { (*context)(); - } catch (simgrid::kernel::context::Context::StopRequest const&) { - XBT_DEBUG("Caught a StopRequest"); + context->Context::stop(); + } catch (simgrid::ForcefulKillException const&) { + XBT_DEBUG("Caught a ForcefulKillException"); } catch (simgrid::Exception const& e) { XBT_INFO("Actor killed by an uncatched exception %s", simgrid::xbt::demangle(typeid(e).name()).get()); throw; } - context->Context::stop(); ASAN_ONLY(context->asan_stop_ = true); context->suspend(); } -/** 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]); -} +namespace simgrid { +namespace kernel { +namespace context { -void UContext::swap_into(SwappedContext* to_) +// UContextFactory +Context* UContextFactory::create_context(std::function&& code, smx_actor_t actor) { - UContext* to = static_cast(to_); - ASAN_ONLY(void* fake_stack = nullptr); - ASAN_ONLY(to->asan_ctx_ = from); - ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_); - swapcontext(&this->uc_, &to->uc_); - ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_); + return new_context(std::move(code), actor, this); } -void UContext::stop() -{ - Context::stop(); - throw StopRequest(); -} -// ParallelUContext +// UContext -void ParallelUContext::run_all() +UContext::UContext(std::function&& code, smx_actor_t actor, SwappedContextFactory* factory) + : SwappedContext(std::move(code), actor, factory) { - threads_working_ = 0; - - // We lazily create the parmap so that all options are actually processed when doing so. - if (parmap_ == nullptr) - parmap_ = new simgrid::xbt::Parmap(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode()); - - // Usually, Parmap::apply() executes the provided function on all elements of the array. - // Here, the executed function does not return the control to the parmap before all the array is processed: - // - suspend() should switch back to the worker_context (either maestro or one of its minions) to return - // the control to the parmap. Instead, it uses parmap_->next() to steal another work, and does it directly. - // It only yields back to worker_context when the work array is exhausted. - // - So, resume() is only launched from the parmap for the first job of each minion. - parmap_->apply( - [](smx_actor_t process) { - ParallelUContext* context = static_cast(process->context_); - context->resume(); - }, - simix_global->process_to_run); -} + /* if the user provided a function for the actor then use it. If not, nothing to do for maestro. */ + if (has_code()) { + getcontext(&this->uc_); + this->uc_.uc_link = nullptr; + this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(get_stack()); + this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_usable_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. -/** Run one particular simulated process on the current thread. - * - * Only applied to the N first elements of the parmap array, where N is the amount of worker threads in the parmap. - * See ParallelUContext::run_all for details. - */ -void ParallelUContext::resume() -{ - // Save the thread number (my body) in an os-thread-specific area - worker_id_ = threads_working_.fetch_add(1, std::memory_order_relaxed); - // Save my current soul (either maestro, or one of the minions) in a permanent area - SwappedContext* worker_context = static_cast(self()); - workers_context_[worker_id_] = worker_context; - // Switch my soul and the actor's one - Context::set_current(this); - worker_context->swap_into(this); - // No body runs that soul anymore at this point, but it is stored in a safe place. - // When the executed actor will do a blocking action, SIMIX_process_yield() will call suspend(), below. -} + 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]); -/** Yield - * - * This function is called when a simulated process wants to yield back to the maestro in a blocking simcall, - * ie in SIMIX_process_yield(). - * - * Actually, it does not really yield back to maestro, but directly into the next executable actor. - * - * This makes the parmap::apply awkward (see ParallelUContext::run_all()) because it only apply regularly - * on the few first elements of the array, but it saves a lot of context switches back to maestro, - * and directly forth to the next executable actor. - */ -void ParallelUContext::suspend() -{ - // Get some more work to directly swap into the next executable actor instead of yielding back to the parmap - boost::optional next_work = parmap_->next(); - SwappedContext* next_context; - if (next_work) { - // There is a next soul to embody (ie, another executable actor) - XBT_DEBUG("Run next process"); - next_context = static_cast(next_work.get()->context_); - } else { - // All actors were run, go back to the parmap context - XBT_DEBUG("No more processes to run"); - // worker_id_ is the identity of my body, stored in thread_local when starting the scheduling round - next_context = workers_context_[worker_id_]; - // When given that soul, the body will wait for the next scheduling round +#if SIMGRID_HAVE_MC + if (MC_is_active()) { + MC_register_stack_area(get_stack(), actor, &(this->uc_), smx_context_usable_stack_size); + } +#endif } +} - // Get the next soul to run, either from another actor or the initial minion's one - Context::set_current(next_context); - this->swap_into(next_context); +void UContext::swap_into(SwappedContext* to_) +{ + UContext* to = static_cast(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_); } + XBT_PRIVATE ContextFactory* sysv_factory() { XBT_VERB("Activating SYSV context factory");