+++ /dev/null
-/* context_sysv - context switching with ucontexts from System V */
-
-/* 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. */
-
-#include <stdarg.h>
-
-#include "xbt/parmap.h"
-#include "smx_private.h"
-#include "src/internal_config.h"
-#include "src/context_sysv_config.h" /* loads context system definitions */
-#include "mc/mc.h"
-
-#ifdef _XBT_WIN32
-# include <xbt/win32_ucontext.h> /* context relative declarations */
-#else
-# include <ucontext.h> /* context relative declarations */
-#endif
-
-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 */
- char *stack; /* the thread stack */
-} s_smx_ctx_sysv_t, *smx_ctx_sysv_t;
-
-#ifdef CONTEXT_THREADS
-static xbt_parmap_t sysv_parmap;
-static smx_ctx_sysv_t* sysv_workers_context; /* space to save the worker's context in each thread */
-static unsigned long 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 smx_ctx_sysv_t sysv_maestro_context;
-
-static int smx_ctx_sysv_factory_finalize(smx_context_factory_t *factory);
-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, smx_process_t process);
-
-static void smx_ctx_sysv_wrapper(int count, ...);
-
-static void smx_ctx_sysv_stop_serial(smx_context_t context);
-static void smx_ctx_sysv_suspend_serial(smx_context_t context);
-static void smx_ctx_sysv_resume_serial(smx_process_t first_process);
-static void smx_ctx_sysv_runall_serial(void);
-
-static void smx_ctx_sysv_stop_parallel(smx_context_t context);
-static void smx_ctx_sysv_suspend_parallel(smx_context_t context);
-static void smx_ctx_sysv_resume_parallel(smx_process_t first_process);
-static void smx_ctx_sysv_runall_parallel(void);
-
-/* 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(smx_ctx_sysv_t) / sizeof(int) + \
- !!(sizeof(smx_ctx_sysv_t) % sizeof(int)))
-
-void SIMIX_ctx_sysv_factory_init(smx_context_factory_t *factory)
-{
- smx_ctx_base_factory_init(factory);
- XBT_VERB("Activating SYSV context factory");
-
- (*factory)->finalize = smx_ctx_sysv_factory_finalize;
- (*factory)->create_context = smx_ctx_sysv_create_context;
- /* Do not overload that method (*factory)->finalize */
- (*factory)->free = smx_ctx_sysv_free;
- (*factory)->name = "smx_sysv_context_factory";
-
- if (SIMIX_context_is_parallel()) {
-#ifdef CONTEXT_THREADS /* To use parallel ucontexts a thread pool is needed */
- int nthreads = SIMIX_context_get_nthreads();
- sysv_parmap = xbt_parmap_new(nthreads, SIMIX_context_get_parallel_mode());
- sysv_workers_context = xbt_new(smx_ctx_sysv_t, nthreads);
- sysv_maestro_context = NULL;
- xbt_os_thread_key_create(&sysv_worker_id_key);
- (*factory)->stop = smx_ctx_sysv_stop_parallel;
- (*factory)->suspend = smx_ctx_sysv_suspend_parallel;
- (*factory)->runall = smx_ctx_sysv_runall_parallel;
-#else
- THROWF(arg_error, 0, "No thread support for parallel context execution");
-#endif
- } else {
- (*factory)->stop = smx_ctx_sysv_stop_serial;
- (*factory)->suspend = smx_ctx_sysv_suspend_serial;
- (*factory)->runall = smx_ctx_sysv_runall_serial;
- }
-}
-
-static int smx_ctx_sysv_factory_finalize(smx_context_factory_t *factory)
-{
-#ifdef CONTEXT_THREADS
- if (sysv_parmap)
- xbt_parmap_destroy(sysv_parmap);
- xbt_free(sysv_workers_context);
-#endif
- return smx_ctx_base_factory_finalize(factory);
-}
-
-static smx_context_t
-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(
- 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_usable_stack_size);
-
- context->uc.uc_stack.ss_size =
- 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:
- makecontext(&context->uc, (void (*)())smx_ctx_sysv_wrapper,
- 1, ctx_addr[0]);
- break;
- case 2:
- makecontext(&context->uc, (void (*)())smx_ctx_sysv_wrapper,
- 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(smx_ctx_sysv_t), sizeof(int), CTX_ADDR_LEN);
- }
- } else {
- if (process != NULL && sysv_maestro_context == NULL)
- sysv_maestro_context = context;
- }
-
-#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 void smx_ctx_sysv_free(smx_context_t context)
-{
-
- if (context) {
- SIMIX_context_stack_delete(((smx_ctx_sysv_t)context)->stack);
- }
- smx_ctx_base_free(context);
-}
-
-static void smx_ctx_sysv_wrapper(int first, ...)
-{
- int ctx_addr[CTX_ADDR_LEN];
- smx_ctx_sysv_t context;
-
- ctx_addr[0] = first;
- if (CTX_ADDR_LEN > 1) {
- va_list ap;
- int i;
- va_start(ap, first);
- for (i = 1; i < CTX_ADDR_LEN; i++)
- ctx_addr[i] = va_arg(ap, int);
- va_end(ap);
- }
- memcpy(&context, ctx_addr, sizeof(smx_ctx_sysv_t));
- (context->super.code) (context->super.argc, context->super.argv);
-
- simix_global->context_factory->stop((smx_context_t) context);
-}
-
-static void smx_ctx_sysv_stop_serial(smx_context_t context)
-{
- smx_ctx_base_stop(context);
- smx_ctx_sysv_suspend_serial(context);
-}
-
-static void smx_ctx_sysv_suspend_serial(smx_context_t context)
-{
- /* determine the next context */
- smx_context_t next_context;
- 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 = xbt_dynar_get_as(
- simix_global->process_to_run,i, smx_process_t)->context;
- }
- else {
- /* all processes were run, return to maestro */
- XBT_DEBUG("No more process to run");
- next_context = (smx_context_t) sysv_maestro_context;
- }
- SIMIX_context_set_current(next_context);
- swapcontext(&((smx_ctx_sysv_t) context)->uc,
- &((smx_ctx_sysv_t) next_context)->uc);
-}
-
-static void smx_ctx_sysv_resume_serial(smx_process_t first_process)
-{
- smx_context_t context = first_process->context;
- SIMIX_context_set_current(context);
- swapcontext(&sysv_maestro_context->uc,
- &((smx_ctx_sysv_t) context)->uc);
-}
-
-static void smx_ctx_sysv_runall_serial(void)
-{
- smx_process_t first_process =
- xbt_dynar_get_as(simix_global->process_to_run, 0, smx_process_t);
- sysv_process_index = 1;
-
- /* execute the first process */
- smx_ctx_sysv_resume_serial(first_process);
-}
-
-static void smx_ctx_sysv_stop_parallel(smx_context_t context)
-{
- smx_ctx_base_stop(context);
- smx_ctx_sysv_suspend_parallel(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); // get the next soul to embody now
- smx_context_t next_context;
- 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 soul to embody (ie, a next process to resume)
- XBT_DEBUG("Run next process");
- next_context = next_work->context;
- }
- else {
- /* all processes were run, go to the barrier */
- XBT_DEBUG("No more processes to run");
- 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]; // deduce the initial soul of that body
- // When given that soul, the body will wait for the next scheduling round
- }
-
- next_stack = &((smx_ctx_sysv_t)next_context)->uc;
-
- SIMIX_context_set_current(next_context);
- swapcontext(&((smx_ctx_sysv_t) context)->uc, next_stack); // get that next soul
-#endif
-}
