X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/cd05fcfa9ff6df9b054060937165d422a536bd99..fcf33975379cd050a6d70b94ae7857910dd01217:/include/simgrid/simix.hpp diff --git a/include/simgrid/simix.hpp b/include/simgrid/simix.hpp index 1122d16cfb..9e3ec63a77 100644 --- a/include/simgrid/simix.hpp +++ b/include/simgrid/simix.hpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2007-2010, 2012-2015. The SimGrid Team. +/* Copyright (c) 2007-2022. The SimGrid Team. * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it @@ -7,190 +7,117 @@ #ifndef SIMGRID_SIMIX_HPP #define SIMGRID_SIMIX_HPP -#include +#include +#include +#include -#include #include -#include -#include -#include -#include -#include +#include -#include -#include - -#include - -XBT_PUBLIC(void) simcall_run_kernel(std::function const& code); +XBT_PUBLIC void simcall_run_answered(std::function const& code, + simgrid::kernel::actor::SimcallObserver* observer); +XBT_PUBLIC void simcall_run_blocking(std::function const& code, + simgrid::kernel::actor::SimcallObserver* observer); +XBT_PUBLIC void simcall_run_object_access(std::function const& code, + simgrid::kernel::actor::ObjectAccessSimcallItem* item); namespace simgrid { -namespace simix { +namespace kernel { +namespace actor { -/** Execute some code in the kernel/maestro +/** Execute some code in kernel context on behalf of the user code. + * + * Every modification of the environment must be protected this way: every setter, constructor and similar. + * Getters don't have to be protected this way, and setters may use the simcall_object_access() variant (see below). + * + * This allows deterministic parallel simulation without any locking, even if almost nobody uses parallel simulation in + * SimGrid. More interestingly it makes every modification of the simulated world observable by the model-checker, + * allowing the whole MC business. + * + * It is highly inspired from the syscalls in a regular operating system, allowing the user code to get some specific + * code executed in the kernel context. But here, there is almost no security involved. Parameters get checked for + * finiteness but that's all. The main goal remain to ensure reproducible ordering of uncomparable events (in + * [parallel] simulation) and observability of events (in model-checking). * - * This can be used to enforce mutual exclusion with other simcall. - * More importantly, this enforces a deterministic/reproducible ordering - * of the operation with respect to other simcalls. + * The code passed as argument is supposed to terminate at the exact same simulated timestamp. + * Do not use it if your code may block waiting for a subsequent event, e.g. if you lock a mutex, + * you may need to wait for that mutex to be unlocked by its current owner. + * Potentially blocking simcall must be issued using simcall_blocking(), right below in this file. */ -template -typename std::result_of::type kernel(F&& code) +template typename std::result_of_t simcall_answered(F&& code, SimcallObserver* observer = nullptr) { // If we are in the maestro, we take the fast path and execute the - // code directly without simcall mashalling/unmarshalling/dispatch: - if (SIMIX_is_maestro()) + // code directly without simcall marshalling/unmarshalling/dispatch: + if (s4u::Actor::is_maestro()) return std::forward(code)(); - // If we are in the application, pass the code to the maestro which is + // If we are in the application, pass the code to the maestro which // executes it for us and reports the result. We use a std::future which // conveniently handles the success/failure value for us. - typedef typename std::result_of::type R; - std::promise promise; - simcall_run_kernel([&]{ - xbt_assert(SIMIX_is_maestro(), "Not in maestro"); - simgrid::xbt::fulfillPromise(promise, std::forward(code)); - }); - return promise.get_future().get(); + using R = typename std::result_of_t; + simgrid::xbt::Result result; + simcall_run_answered([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward(code)); }, observer); + return result.get(); } -class Context; -class ContextFactory; - -XBT_PUBLIC_CLASS ContextFactory { -private: - std::string name_; -public: - - explicit ContextFactory(std::string name) : name_(std::move(name)) {} - virtual ~ContextFactory(); - virtual Context* create_context(std::function code, - void_pfn_smxprocess_t cleanup, smx_process_t process) = 0; - - // Optional methods for attaching main() as a context: - - /** Creates a context from the current context of execution - * - * This will not work on all implementation of `ContextFactory`. - */ - virtual Context* attach(void_pfn_smxprocess_t cleanup_func, smx_process_t process); - virtual Context* create_maestro(std::function code, smx_process_t process); - - virtual void run_all() = 0; - virtual Context* self(); - std::string const& name() const - { - return name_; - } -private: - void declare_context(void* T, std::size_t size); -protected: - template - T* new_context(Args&&... args) - { - T* context = new T(std::forward(args)...); - this->declare_context(context, sizeof(T)); - return context; - } -}; - -XBT_PUBLIC_CLASS Context { -private: - std::function code_; - void_pfn_smxprocess_t cleanup_func_ = nullptr; - smx_process_t process_ = nullptr; -public: - bool iwannadie; -public: - Context(std::function code, - void_pfn_smxprocess_t cleanup_func, - smx_process_t process); - void operator()() - { - code_(); - } - bool has_code() const - { - return (bool) code_; - } - smx_process_t process() - { - return this->process_; - } - void set_cleanup(void_pfn_smxprocess_t cleanup) - { - cleanup_func_ = cleanup; - } - - // Virtual methods - virtual ~Context(); - virtual void stop(); - virtual void suspend() = 0; -}; - -XBT_PUBLIC_CLASS AttachContext : public Context { -public: - - AttachContext(std::function code, - void_pfn_smxprocess_t cleanup_func, - smx_process_t process) - : Context(std::move(code), cleanup_func, process) - {} - - ~AttachContext() override; - - /** Called by the context when it is ready to give control - * to the maestro. - */ - virtual void attach_start() = 0; - - /** Called by the context when it has finished its job */ - virtual void attach_stop() = 0; -}; +/** Use a setter on the `item` object. That's a simcall only if running in parallel or with MC activated. + * + * Simulation without MC and without parallelism (contexts/nthreads=1) will not pay the price of a simcall for an + * harmless setter. When running in parallel, you want your write access to be done in a mutual exclusion way, while the + * getters can still occure out of order. + * + * When running in MC, you want to make this access visible to the checker. Actually in this case, it's not visible from + * the checker (and thus still use a fast track) if the setter is called from the actor that created the object. + */ +template typename std::result_of_t simcall_object_access(ObjectAccessSimcallItem* item, F&& code) +{ + // If we are in the maestro, we take the fast path and execute the code directly + if (simgrid::s4u::Actor::is_maestro()) + return std::forward(code)(); -XBT_PUBLIC(void) set_maestro(std::function code); -XBT_PUBLIC(void) create_maestro(std::function code); + // If called from another thread, do a real simcall. It will be short-cut on need + using R = typename std::result_of_t; + simgrid::xbt::Result result; + simcall_run_object_access([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward(code)); }, item); -} + return result.get(); } -/* - * Type of function that creates a process. - * The function must accept the following parameters: - * void* process: the process created will be stored there - * const char *name: a name for the object. It is for user-level information and can be NULL - * xbt_main_func_t code: is a function describing the behavior of the process - * void *data: data a pointer to any data one may want to attach to the new object. - * sg_host_t host: the location where the new process is executed - * int argc, char **argv: parameters passed to code - * xbt_dict_t pros: properties +/** Execute some code (that does not return immediately) in kernel context + * + * This is very similar to simcall_answered() above, but the calling actor will not get rescheduled until + * actor->simcall_answer() is called explicitly. + * + * This is meant for blocking actions. For example, locking a mutex is a blocking simcall. + * First it's a simcall because that's obviously a modification of the world. Then, that's a blocking simcall because if + * the mutex happens not to be free, the actor is added to a queue of actors in the mutex. Every mutex->unlock() takes + * the first actor from the queue, mark it as current owner of the mutex and call actor->simcall_answer() to mark that + * this mutex is now unblocked and ready to run again. If the mutex is initially free, the calling actor is unblocked + * right away with actor->simcall_answer() once the mutex is marked as locked. + * + * If your code never calls actor->simcall_answer() itself, the actor will never return from its simcall. + * + * The return value is obtained from observer->get_result() if it exists. Otherwise void is returned. */ -typedef smx_process_t (*smx_creation_func_t) ( - /* name */ const char*, - std::function code, - /* userdata */ void*, - /* hostname */ const char*, - /* kill_time */ double, - /* props */ xbt_dict_t, - /* auto_restart */ int, - /* parent_process */ smx_process_t); - -extern "C" -XBT_PUBLIC(void) SIMIX_function_register_process_create(smx_creation_func_t function); - -XBT_PUBLIC(smx_process_t) simcall_process_create(const char *name, - std::function code, - void *data, - const char *hostname, - double kill_time, - xbt_dict_t properties, - int auto_restart); +template void simcall_blocking(F&& code, SimcallObserver* observer = nullptr) +{ + xbt_assert(not s4u::Actor::is_maestro(), "Cannot execute blocking call in kernel mode"); -XBT_PUBLIC(smx_timer_t) SIMIX_timer_set(double date, std::function callback); + // Pass the code to the maestro which executes it for us and reports the result. We use a std::future which + // conveniently handles the success/failure value for us. + simgrid::xbt::Result result; + simcall_run_blocking([&result, &code] { simgrid::xbt::fulfill_promise(result, std::forward(code)); }, observer); + result.get(); // rethrow stored exception if any +} -template inline -XBT_PUBLIC(smx_timer_t) SIMIX_timer_set(double date, R(*callback)(T*), T* arg) +template +auto simcall_blocking(F&& code, Observer* observer) -> decltype(observer->get_result()) { - return SIMIX_timer_set(date, [=](){ callback(arg); }); + simcall_blocking(std::forward(code), static_cast(observer)); + return observer->get_result(); } - +// compact namespaces are C++17 and this is a public header file so let's stick to C++14 +} // namespace actor +} // namespace kernel +} // namespace simgrid #endif