X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/24bfbf4652ba5cbe63f11767a1b9fb14e5508c3a..e7f87282045aad5c82fee922140dc5c60320b87b:/src/kernel/context/ContextUnix.cpp diff --git a/src/kernel/context/ContextUnix.cpp b/src/kernel/context/ContextUnix.cpp index 692898d007..ea21e2579e 100644 --- a/src/kernel/context/ContextUnix.cpp +++ b/src/kernel/context/ContextUnix.cpp @@ -1,233 +1,117 @@ -/* Copyright (c) 2009-2015. The SimGrid Team. - * All rights reserved. */ +/* Copyright (c) 2009-2017. 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 */ +/* \file UContext.cpp Context switching with ucontexts from System V */ -#include +#include "ContextUnix.hpp" -#include -#include /* context relative declarations */ - -#include "xbt/parmap.h" -#include "src/simix/smx_private.h" -#include "src/internal_config.h" #include "mc/mc.h" +#include "src/mc/mc_ignore.h" +#include "src/simix/ActorImpl.hpp" + +XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); /** 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))) + * Support up to two ints. */ +constexpr int CTX_ADDR_LEN = 2; -/** 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); - } -} - -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; +static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int), + "Ucontexts are not supported on this arch yet"); // 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, ...); +static void smx_ctx_sysv_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); + + try { + (*context)(); + context->Context::stop(); + } catch (simgrid::kernel::context::Context::StopRequest const&) { + XBT_DEBUG("Caught a StopRequest"); + } + context->suspend(); +} 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_process_t process); - ~UContext() override; -}; - -class SerialUContext : public UContext { -public: - SerialUContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_process_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_process_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_process_t process) override; - void run_all() override; -}; - -XBT_PRIVATE ContextFactory* sysv_factory() -{ - XBT_VERB("Activating SYSV context factory"); - return new UContextFactory(); -} +// UContextFactory -UContextFactory::UContextFactory() : ContextFactory("UContextFactory") +UContextFactory::UContextFactory() : ContextFactory("UContextFactory"), parallel_(SIMIX_context_is_parallel()) { - 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); + UContext::setMaestro(nullptr); + if (parallel_) { +#if HAVE_THREAD_CONTEXTS + ParallelUContext::initialize(); #else - THROWF(arg_error, 0, "No thread support for parallel context execution"); + xbt_die("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); + if (parallel_) + ParallelUContext::finalize(); #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() +Context* UContextFactory::create_context(std::function code, void_pfn_smxprocess_t cleanup, smx_actor_t process) { - 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_process_t process = (smx_process_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_process_t first_process = - xbt_dynar_get_as(simix_global->process_to_run, 0, smx_process_t); - sysv_process_index = 1; - SerialUContext* context = - static_cast(first_process->context); - context->resume(); - } +#if HAVE_THREAD_CONTEXTS + if (parallel_) + return new_context(std::move(code), cleanup, process); + else +#endif + return new_context(std::move(code), cleanup, process); } -Context* UContextFactory::create_context(std::function code, - void_pfn_smxprocess_t cleanup, smx_process_t 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 (sysv_parallel) - return new_context(std::move(code), cleanup, process); +#if HAVE_THREAD_CONTEXTS + if (parallel_) + ParallelUContext::run_all(); else - return new_context(std::move(code), cleanup, process); +#endif + SerialUContext::run_all(); } -UContext::UContext(std::function code, - void_pfn_smxprocess_t cleanup_func, smx_process_t process) - : Context(std::move(code), cleanup_func, process) +// UContext + +UContext* UContext::maestro_context_ = nullptr; + +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(); + 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); - simgrid_makecontext(&this->uc_, smx_ctx_sysv_wrapper, this); + UContext::make_ctx(&this->uc_, UContext::wrapper, this); } else { - if (process != nullptr && sysv_maestro_context == nullptr) - sysv_maestro_context = this; + if (process != nullptr && maestro_context_ == nullptr) + maestro_context_ = this; } -#if HAVE_MC +#if SIMGRID_HAVE_MC if (MC_is_active() && has_code()) { - MC_register_stack_area(this->stack_, process, - &(this->uc_), smx_context_usable_stack_size); + MC_register_stack_area(this->stack_, process, &(this->uc_), smx_context_usable_stack_size); } #endif } @@ -237,148 +121,173 @@ UContext::~UContext() SIMIX_context_stack_delete(this->stack_); } -}}} // namespace simgrid::kernel::context - -static void smx_ctx_sysv_wrapper(int first, ...) +void UContext::wrapper(int i1, int i2) { - // Rebuild the Context* pointer from the integers: - int ctx_addr[CTX_ADDR_LEN]; - 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(simgrid::kernel::context::UContext*)); - - (*context)(); - context->stop(); + smx_ctx_sysv_wrapper(i1, i2); } -namespace simgrid { -namespace kernel { -namespace context { +/** 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 SerialUContext::stop() +void UContext::stop() { Context::stop(); - this->suspend(); + 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 = nullptr; - unsigned long int i = sysv_process_index++; + SerialUContext* next_context; + unsigned long int i = process_index_; + process_index_++; - if (i < xbt_dynar_length(simix_global->process_to_run)) { + if (i < simix_global->process_to_run.size()) { /* execute the next process */ XBT_DEBUG("Run next process"); - next_context = (SerialUContext*) xbt_dynar_get_as( - simix_global->process_to_run,i, smx_process_t)->context; - } - else { + next_context = static_cast(simix_global->process_to_run[i]->context); + } else { /* all processes were run, return to maestro */ XBT_DEBUG("No more process to run"); - next_context = (SerialUContext*) sysv_maestro_context; + next_context = static_cast(UContext::getMaestro()); } SIMIX_context_set_current(next_context); - swapcontext(&this->uc_, &next_context->uc_); + UContext::swap(this, next_context); } -// UContextSerial - void SerialUContext::resume() { SIMIX_context_set_current(this); - swapcontext(&((SerialUContext*)sysv_maestro_context)->uc_, &this->uc_); + UContext::swap(UContext::getMaestro(), this); } -void ParallelUContext::stop() +void SerialUContext::run_all() { - UContext::stop(); - this->suspend(); + if (simix_global->process_to_run.empty()) + return; + smx_actor_t first_process = simix_global->process_to_run.front(); + process_index_ = 1; + static_cast(first_process->context)->resume(); } -/** Run one particular simulated process on the current thread. */ -void ParallelUContext::resume() -{ +// ParallelUContext + #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 +simgrid::xbt::Parmap* ParallelUContext::parmap_; +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::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(SIMIX_context_get_nthreads(), SIMIX_context_get_parallel_mode()); + parmap_->apply( + [](smx_actor_t process) { + ParallelUContext* context = static_cast(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). + * 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() { -#if HAVE_THREAD_CONTEXTS /* determine the next context */ // Get the next soul to embody now: - smx_process_t next_work = (smx_process_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) { + boost::optional 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 = (ParallelUContext*) next_work->context; - } - else { + next_context = static_cast(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 = - (uintptr_t) xbt_os_thread_get_specific(sysv_worker_id_key); + // Get back the identity of my body that was stored when starting the scheduling round + uintptr_t worker_id = reinterpret_cast(xbt_os_thread_get_specific(worker_id_key_)); // Deduce the initial soul of that body - next_context = (ParallelUContext*) sysv_workers_context[worker_id]; + next_context = 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 + // Get the next soul to run, either simulated or initial minion's one: + UContext::swap(this, next_context); } -}}} // namespace simgrid::kernel::context +/** Run one particular simulated process on the current thread. */ +void ParallelUContext::resume() +{ + // What is my containing body? + uintptr_t worker_id = __sync_fetch_and_add(&threads_working_, 1); + // Store the number of my containing body in os-thread-specific area : + xbt_os_thread_set_specific(worker_id_key_, reinterpret_cast(worker_id)); + // Get my current soul: + ParallelUContext* worker_context = static_cast(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