X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/9bc2f7734295810a24f98d65169f06705e3ea951..b9945098e2ba4e7b639e0c2245835d44800c1b29:/src/kernel/context/ContextUnix.cpp diff --git a/src/kernel/context/ContextUnix.cpp b/src/kernel/context/ContextUnix.cpp index 226236e1b6..70a87d20ca 100644 --- a/src/kernel/context/ContextUnix.cpp +++ b/src/kernel/context/ContextUnix.cpp @@ -1,380 +1,108 @@ -/* Copyright (c) 2009-2015. 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 /* context relative declarations */ +#include "context_private.hpp" #include "mc/mc.h" -#include "src/simix/ActorImpl.hpp" -#include "src/simix/smx_private.h" -#include "xbt/parmap.h" +#include "simgrid/Exception.hpp" +#include "src/kernel/actor/ActorImpl.hpp" +#include "src/mc/mc_ignore.hpp" +#include "src/simix/smx_private.hpp" -/** Many integers are needed to store a pointer - * - * This is a bit paranoid about sizeof(smx_ctx_sysv_t) not being a multiple - * of sizeof(int), but it doesn't harm. */ -#define CTX_ADDR_LEN \ - (sizeof(void*) / sizeof(int) + \ - !!(sizeof(void*) % sizeof(int))) - -/** 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. */ -static void simgrid_makecontext(ucontext_t* ucp, void (*func)(int first, ...), void* arg) -{ - int ctx_addr[CTX_ADDR_LEN]; - memcpy(ctx_addr, &arg, sizeof(void*)); - switch (CTX_ADDR_LEN) { - case 1: - makecontext(ucp, (void (*)())func, 1, ctx_addr[0]); - break; - case 2: - makecontext(ucp, (void (*)()) func, 2, ctx_addr[0], ctx_addr[1]); - break; - default: - xbt_die("Ucontexts are not supported on this arch yet (addr len = %zu/%zu = %zu)", sizeof(void*), sizeof(int), CTX_ADDR_LEN); - } -} +#include "ContextUnix.hpp" XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); -namespace simgrid { -namespace kernel { -namespace context { - class UContext; - class SerialUContext; - class ParallelUContext; - class UContextFactory; -}}} - -#if HAVE_THREAD_CONTEXTS -static xbt_parmap_t sysv_parmap; -static simgrid::kernel::context::ParallelUContext** sysv_workers_context; /* space to save the worker's context in each thread */ -static uintptr_t sysv_threads_working; /* number of threads that have started their work */ -static xbt_os_thread_key_t sysv_worker_id_key; /* thread-specific storage for the thread id */ -#endif -static unsigned long sysv_process_index = 0; /* index of the next process to run in the - * list of runnable processes */ -static simgrid::kernel::context::UContext* sysv_maestro_context; -static bool sysv_parallel; - -// The name of this function is currently hardcoded in the code (as string). -// Do not change it without fixing those references as well. -static void smx_ctx_sysv_wrapper(int first, ...); - -namespace simgrid { -namespace kernel { -namespace context { - -class UContext : public Context { -protected: - ucontext_t uc_; /* the ucontext that executes the code */ - char *stack_ = nullptr; /* the thread stack */ -public: - friend UContextFactory; - UContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_actor_t process); - ~UContext() override; -}; - -class SerialUContext : public UContext { -public: - SerialUContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : UContext(std::move(code), cleanup_func, process) - {} - void stop() override; - void suspend() override; - void resume(); -}; - -class ParallelUContext : public UContext { -public: - ParallelUContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : UContext(std::move(code), cleanup_func, process) - {} - void stop() override; - void suspend() override; - void resume(); -}; - -class UContextFactory : public ContextFactory { -public: - friend UContext; - friend SerialUContext; - friend ParallelUContext; - - UContextFactory(); - ~UContextFactory() override; - Context* create_context(std::function code, - void_pfn_smxprocess_t cleanup, smx_actor_t process) override; - void run_all() override; -}; - -XBT_PRIVATE ContextFactory* sysv_factory() -{ - XBT_VERB("Activating SYSV context factory"); - return new UContextFactory(); -} - -UContextFactory::UContextFactory() : ContextFactory("UContextFactory") -{ - if (SIMIX_context_is_parallel()) { - sysv_parallel = true; -#if HAVE_THREAD_CONTEXTS /* To use parallel ucontexts a thread pool is needed */ - int nthreads = SIMIX_context_get_nthreads(); - sysv_parmap = nullptr; - sysv_workers_context = xbt_new(ParallelUContext*, nthreads); - sysv_maestro_context = nullptr; - xbt_os_thread_key_create(&sysv_worker_id_key); -#else - THROWF(arg_error, 0, "No thread support for parallel context execution"); -#endif - } else { - sysv_parallel = false; - } -} - -UContextFactory::~UContextFactory() -{ -#if HAVE_THREAD_CONTEXTS - if (sysv_parmap) - xbt_parmap_destroy(sysv_parmap); - xbt_free(sysv_workers_context); -#endif -} - -/* 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 (sysv_parallel) { - #if HAVE_THREAD_CONTEXTS - sysv_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 smx_ctx_sysv_resume_parallel 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 (sysv_parmap == nullptr) - sysv_parmap = xbt_parmap_new( - SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode()); - - xbt_parmap_apply(sysv_parmap, - [](void* arg) { - smx_actor_t process = (smx_actor_t) arg; - ParallelUContext* context = static_cast(process->context); - context->resume(); - }, - simix_global->process_to_run); - #else - xbt_die("You asked for a parallel execution, but you don't have any threads."); - #endif - } else { - // Serial: - if (xbt_dynar_is_empty(simix_global->process_to_run)) - return; - - smx_actor_t first_process = - xbt_dynar_get_as(simix_global->process_to_run, 0, smx_actor_t); - sysv_process_index = 1; - SerialUContext* context = - static_cast(first_process->context); - context->resume(); - } -} - -Context* UContextFactory::create_context(std::function code, - void_pfn_smxprocess_t cleanup, smx_actor_t process) -{ - if (sysv_parallel) - return new_context(std::move(code), cleanup, process); - else - return new_context(std::move(code), cleanup, process); -} +/** Up to two integers may be needed to store a pointer on the system we target */ +constexpr int CTX_ADDR_LEN = 2; -UContext::UContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_actor_t process) - : Context(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()) { - this->stack_ = (char*) 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); - simgrid_makecontext(&this->uc_, smx_ctx_sysv_wrapper, this); - } else { - if (process != nullptr && sysv_maestro_context == nullptr) - sysv_maestro_context = this; - } - -#if HAVE_MC - if (MC_is_active() && has_code()) { - MC_register_stack_area(this->stack_, process, - &(this->uc_), smx_context_usable_stack_size); - } -#endif -} +static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int), + "Ucontexts are not supported on this arch yet. Please increase CTX_ADDR_LEN."); -UContext::~UContext() -{ - SIMIX_context_stack_delete(this->stack_); +/* 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); } -}}} // namespace simgrid::kernel::context - -static void smx_ctx_sysv_wrapper(int first, ...) +// 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_wrapper(int i1, int i2) { // Rebuild the Context* pointer from the integers: - int ctx_addr[CTX_ADDR_LEN]; + int ctx_addr[CTX_ADDR_LEN] = {i1, i2}; simgrid::kernel::context::UContext* context; - ctx_addr[0] = first; - if (CTX_ADDR_LEN > 1) { - va_list ap; - va_start(ap, first); - for (unsigned i = 1; i < CTX_ADDR_LEN; i++) - ctx_addr[i] = va_arg(ap, int); - va_end(ap); + 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::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; } - memcpy(&context, ctx_addr, sizeof(simgrid::kernel::context::UContext*)); - - (*context)(); - context->stop(); + ASAN_ONLY(context->asan_stop_ = true); + context->suspend(); } namespace simgrid { namespace kernel { namespace context { -void SerialUContext::stop() +// UContextFactory +Context* UContextFactory::create_context(std::function&& code, smx_actor_t actor) { - Context::stop(); - this->suspend(); + return new_context(std::move(code), actor, this); } -void SerialUContext::suspend() -{ - /* determine the next context */ - SerialUContext* next_context = nullptr; - unsigned long int i = sysv_process_index++; - - if (i < xbt_dynar_length(simix_global->process_to_run)) { - /* execute the next process */ - XBT_DEBUG("Run next process"); - next_context = (SerialUContext*) xbt_dynar_get_as( - simix_global->process_to_run,i, smx_actor_t)->context; - } - else { - /* all processes were run, return to maestro */ - XBT_DEBUG("No more process to run"); - next_context = (SerialUContext*) sysv_maestro_context; - } - SIMIX_context_set_current(next_context); - swapcontext(&this->uc_, &next_context->uc_); -} -// UContextSerial +// UContext -void SerialUContext::resume() +UContext::UContext(std::function&& code, smx_actor_t actor, SwappedContextFactory* factory) + : SwappedContext(std::move(code), actor, factory) { - SIMIX_context_set_current(this); - swapcontext(&((SerialUContext*)sysv_maestro_context)->uc_, &this->uc_); + /* 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. + + 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()) { + MC_register_stack_area(get_stack(), actor, &(this->uc_), smx_context_usable_stack_size); + } +#endif + } } -void ParallelUContext::stop() +void UContext::swap_into(SwappedContext* to_) { - UContext::stop(); - this->suspend(); + 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_); } -/** Run one particular simulated process on the current thread. */ -void ParallelUContext::resume() -{ -#if HAVE_THREAD_CONTEXTS - // What is my containing body? - uintptr_t worker_id = __sync_fetch_and_add(&sysv_threads_working, 1); - // Store the number of my containing body in os-thread-specific area : - xbt_os_thread_set_specific(sysv_worker_id_key, (void*) worker_id); - // Get my current soul: - ParallelUContext* worker_context = (ParallelUContext*) SIMIX_context_self(); - // Write down that this soul is hosted in that body (for now) - sysv_workers_context[worker_id] = worker_context; - // Retrieve the system-level info that fuels this soul: - ucontext_t* worker_stack = &((ParallelUContext*) worker_context)->uc_; - // Write in simix that I switched my soul - SIMIX_context_set_current(this); - // Actually do that using the relevant library call: - swapcontext(worker_stack, &this->uc_); - // 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 -} - -/** 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() +XBT_PRIVATE ContextFactory* sysv_factory() { -#if HAVE_THREAD_CONTEXTS - /* determine the next context */ - // Get the next soul to embody now: - smx_actor_t next_work = (smx_actor_t) xbt_parmap_next(sysv_parmap); - ParallelUContext* next_context = nullptr; - // Will contain the next soul to run, either simulated or initial minion's one - ucontext_t* next_stack; - - if (next_work != nullptr) { - // There is a next soul to embody (ie, a next process to resume) - XBT_DEBUG("Run next process"); - next_context = (ParallelUContext*) next_work->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 = - (uintptr_t) xbt_os_thread_get_specific(sysv_worker_id_key); - // Deduce the initial soul of that body - next_context = (ParallelUContext*) sysv_workers_context[worker_id]; - // When given that soul, the body will wait for the next scheduling round - } - - next_stack = &next_context->uc_; - - SIMIX_context_set_current(next_context); - // Get that next soul: - swapcontext(&this->uc_, next_stack); -#endif + XBT_VERB("Activating SYSV context factory"); + return new UContextFactory(); } - }}} // namespace simgrid::kernel::context -