X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d0ffc37686edcc803601f76ab51fdfed5fc2f241..3203ed1f4fb6f4617e94d5351661ba07e8b8f833:/src/simix/smx_context_sysv.c diff --git a/src/simix/smx_context_sysv.c b/src/simix/smx_context_sysv.c index 3af7b3cef9..050249923d 100644 --- a/src/simix/smx_context_sysv.c +++ b/src/simix/smx_context_sysv.c @@ -1,38 +1,31 @@ /* context_sysv - context switching with ucontexts from System V */ -/* Copyright (c) 2009-2013. The SimGrid Team. +/* Copyright (c) 2009-2015. 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. */ +/* 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. */ #include #include "xbt/parmap.h" #include "smx_private.h" -#include "internal_config.h" -#include "context_sysv_config.h" /* loads context system definitions */ +#include "src/internal_config.h" +#include "src/context_sysv_config.h" /* loads context system definitions */ #include "mc/mc.h" #ifdef _XBT_WIN32 -# include /* context relative declarations */ +# include /* context relative declarations */ #else # include /* context relative declarations */ #endif -#ifdef HAVE_VALGRIND_VALGRIND_H -# include -#endif /* HAVE_VALGRIND_VALGRIND_H */ - XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context); typedef struct s_smx_ctx_sysv { s_smx_ctx_base_t super; /* Fields of super implementation */ ucontext_t uc; /* the ucontext that executes the code */ -#ifdef HAVE_VALGRIND_VALGRIND_H - unsigned int valgrind_stack_id; /* the valgrind stack id */ -#endif - char stack[0]; /* the thread stack (must remain the last element of the structure) */ + char *stack; /* the thread stack */ } s_smx_ctx_sysv_t, *smx_ctx_sysv_t; #ifdef CONTEXT_THREADS @@ -46,16 +39,10 @@ static unsigned long sysv_process_index = 0; /* index of the next process to r static smx_ctx_sysv_t sysv_maestro_context; static int smx_ctx_sysv_factory_finalize(smx_context_factory_t *factory); -static smx_context_t -smx_ctx_sysv_create_context_sized(size_t structure_size, - xbt_main_func_t code, int argc, - char **argv, - void_pfn_smxprocess_t cleanup_func, - void *data); static void smx_ctx_sysv_free(smx_context_t context); static smx_context_t smx_ctx_sysv_create_context(xbt_main_func_t code, int argc, char **argv, - void_pfn_smxprocess_t cleanup_func, void* data); + void_pfn_smxprocess_t cleanup_func, smx_process_t process); static void smx_ctx_sysv_wrapper(int count, ...); @@ -117,40 +104,35 @@ static int smx_ctx_sysv_factory_finalize(smx_context_factory_t *factory) } static smx_context_t -smx_ctx_sysv_create_context_sized(size_t size, xbt_main_func_t code, - int argc, char **argv, - void_pfn_smxprocess_t cleanup_func, - void *data) +smx_ctx_sysv_create_context(xbt_main_func_t code, int argc, char **argv, + void_pfn_smxprocess_t cleanup_func, + smx_process_t process) { int ctx_addr[CTX_ADDR_LEN]; smx_ctx_sysv_t context = - (smx_ctx_sysv_t) smx_ctx_base_factory_create_context_sized(size, - code, - argc, - argv, - cleanup_func, - data); + (smx_ctx_sysv_t) smx_ctx_base_factory_create_context_sized( + sizeof(s_smx_ctx_sysv_t), + code, + argc, + argv, + cleanup_func, + process); /* if the user provided a function for the process then use it, otherwise it is the context for maestro */ if (code) { + context->stack = SIMIX_context_stack_new(); getcontext(&(context->uc)); context->uc.uc_link = NULL; context->uc.uc_stack.ss_sp = - pth_skaddr_makecontext(context->stack, smx_context_stack_size); + pth_skaddr_makecontext(context->stack, smx_context_usable_stack_size); context->uc.uc_stack.ss_size = - pth_sksize_makecontext(context->stack, smx_context_stack_size); - -#ifdef HAVE_VALGRIND_VALGRIND_H - context->valgrind_stack_id = - VALGRIND_STACK_REGISTER(context->uc.uc_stack.ss_sp, - ((char *) context->uc.uc_stack.ss_sp) + - context->uc.uc_stack.ss_size); -#endif /* HAVE_VALGRIND_VALGRIND_H */ + pth_sksize_makecontext(context->stack, smx_context_usable_stack_size); + memcpy(ctx_addr, &context, sizeof(smx_ctx_sysv_t)); switch (CTX_ADDR_LEN) { case 1: @@ -166,38 +148,25 @@ smx_ctx_sysv_create_context_sized(size_t size, xbt_main_func_t code, sizeof(smx_ctx_sysv_t), sizeof(int), CTX_ADDR_LEN); } } else { - if(data != NULL && sysv_maestro_context == NULL) + if (process != NULL && sysv_maestro_context == NULL) sysv_maestro_context = context; } - if(MC_is_active() && code) - MC_new_stack_area(context, ((smx_process_t)((smx_context_t)context)->data)->name, &(context->uc), size); +#ifdef HAVE_MC + if (MC_is_active() && code) { + MC_register_stack_area(context->stack, ((smx_context_t)context)->process, + &(context->uc), smx_context_usable_stack_size); + } +#endif return (smx_context_t) context; } -static smx_context_t -smx_ctx_sysv_create_context(xbt_main_func_t code, int argc, char **argv, - void_pfn_smxprocess_t cleanup_func, - void *data) -{ - - return smx_ctx_sysv_create_context_sized(sizeof(s_smx_ctx_sysv_t) + smx_context_stack_size, - code, argc, argv, cleanup_func, - data); - -} - static void smx_ctx_sysv_free(smx_context_t context) { if (context) { - -#ifdef HAVE_VALGRIND_VALGRIND_H - VALGRIND_STACK_DEREGISTER(((smx_ctx_sysv_t) - context)->valgrind_stack_id); -#endif /* HAVE_VALGRIND_VALGRIND_H */ - + SIMIX_context_stack_delete(((smx_ctx_sysv_t)context)->stack); } smx_ctx_base_free(context); } @@ -274,54 +243,70 @@ static void smx_ctx_sysv_stop_parallel(smx_context_t context) smx_ctx_sysv_suspend_parallel(context); } -static void smx_ctx_sysv_suspend_parallel(smx_context_t context) -{ +/* 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. + */ +static void smx_ctx_sysv_runall_parallel(void) { +#ifdef CONTEXT_THREADS + 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 + xbt_parmap_apply(sysv_parmap, (void_f_pvoid_t) smx_ctx_sysv_resume_parallel, + simix_global->process_to_run); +#else + xbt_die("You asked for a parallel execution, but you don't have any threads."); +#endif +} + +/* This function is in charge of running one particular simulated process on the current thread */ +static void smx_ctx_sysv_resume_parallel(smx_process_t simulated_process_to_run) { +#ifdef CONTEXT_THREADS + unsigned long worker_id = __sync_fetch_and_add(&sysv_threads_working, 1); // what is my containing body? + xbt_os_thread_set_specific(sysv_worker_id_key, (void*) worker_id); // Store the number of my containing body in os-thread-specific area + smx_ctx_sysv_t worker_context = (smx_ctx_sysv_t)SIMIX_context_self(); // get my current soul + sysv_workers_context[worker_id] = worker_context; // write down that this soul is hosted in that body (for now) + ucontext_t* worker_stack = &worker_context->uc; // retrieves the system-level info that fuels this soul + + smx_context_t context = simulated_process_to_run->context; // That's the first soul that I should become + SIMIX_context_set_current(context); // write in simix that I switched my soul + swapcontext(worker_stack, &((smx_ctx_sysv_t) context)->uc); // actually do that using the relevant syscall + // 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 +} + +/* 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). + */ +static void smx_ctx_sysv_suspend_parallel(smx_context_t context) { #ifdef CONTEXT_THREADS /* determine the next context */ - smx_process_t next_work = xbt_parmap_next(sysv_parmap); + smx_process_t next_work = xbt_parmap_next(sysv_parmap); // get the next soul to embody now smx_context_t next_context; - ucontext_t* next_stack; + ucontext_t* next_stack; // will contain the next soul to run, either simulated or initial minion's one - if (next_work != NULL) { - /* there is a next process to resume */ + if (next_work != NULL) { // there is a next soul to embody (ie, a next process to resume) XBT_DEBUG("Run next process"); next_context = next_work->context; - next_stack = &((smx_ctx_sysv_t) next_context)->uc; } else { /* all processes were run, go to the barrier */ XBT_DEBUG("No more processes to run"); - unsigned long worker_id = + unsigned long worker_id = // Get back the identity of my body that was stored when starting the scheduling round (unsigned long) xbt_os_thread_get_specific(sysv_worker_id_key); - next_context = (smx_context_t)sysv_workers_context[worker_id]; - next_stack = &((smx_ctx_sysv_t)next_context)->uc; + next_context = (smx_context_t)sysv_workers_context[worker_id]; // deduce the initial soul of that body + // When given that soul, the body will wait for the next scheduling round } - SIMIX_context_set_current(next_context); - swapcontext(&((smx_ctx_sysv_t) context)->uc, next_stack); -#endif -} - -static void smx_ctx_sysv_resume_parallel(smx_process_t first_process) -{ -#ifdef CONTEXT_THREADS - unsigned long worker_id = __sync_fetch_and_add(&sysv_threads_working, 1); - xbt_os_thread_set_specific(sysv_worker_id_key, (void*) worker_id); - smx_ctx_sysv_t worker_context = (smx_ctx_sysv_t)SIMIX_context_self(); - sysv_workers_context[worker_id] = worker_context; - ucontext_t* worker_stack = &worker_context->uc; + next_stack = &((smx_ctx_sysv_t)next_context)->uc; - smx_context_t context = first_process->context; - SIMIX_context_set_current(context); - swapcontext(worker_stack, &((smx_ctx_sysv_t) context)->uc); -#endif -} - -static void smx_ctx_sysv_runall_parallel(void) -{ -#ifdef CONTEXT_THREADS - sysv_threads_working = 0; - xbt_parmap_apply(sysv_parmap, (void_f_pvoid_t) smx_ctx_sysv_resume_parallel, - simix_global->process_to_run); + SIMIX_context_set_current(next_context); + swapcontext(&((smx_ctx_sysv_t) context)->uc, next_stack); // get that next soul #endif }