X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f365d61a634d854a3244979c0524de3cf3a74f72..b3ca3a517af21780e88cc89869b16927d1fea68a:/src/simix/smx_context.c diff --git a/src/simix/smx_context.c b/src/simix/smx_context.c index 4926372722..f222f62f28 100644 --- a/src/simix/smx_context.c +++ b/src/simix/smx_context.c @@ -1,6 +1,6 @@ /* a fast and simple context switching library */ -/* Copyright (c) 2009, 2010. The SimGrid Team. +/* Copyright (c) 2009-2014. The SimGrid Team. * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it @@ -10,17 +10,38 @@ #include "xbt/log.h" #include "xbt/swag.h" #include "xbt/xbt_os_thread.h" -#include "src/simix/private.h" -#include "simix/context.h" -#include "gras_config.h" +#include "smx_private.h" +#include "simgrid/sg_config.h" +#include "internal_config.h" +#include "simgrid/modelchecker.h" + + +#ifdef _WIN32 +#include +#else +#include +#endif + +#ifdef __MINGW32__ +#define _aligned_malloc __mingw_aligned_malloc +#define _aligned_free __mingw_aligned_free +#endif //MINGW + + + +#ifdef HAVE_VALGRIND_VALGRIND_H +# include +#endif XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix, - "Context switching mecanism"); + "Context switching mechanism"); char* smx_context_factory_name = NULL; /* factory name specified by --cfg=contexts/factory:value */ smx_ctx_factory_initializer_t smx_factory_initializer_to_use = NULL; -int smx_context_stack_size = 128 * 1024; - +int smx_context_stack_size; +int smx_context_stack_size_was_set = 0; +int smx_context_guard_size; +int smx_context_guard_size_was_set = 0; #ifdef HAVE_THREAD_LOCAL_STORAGE static __thread smx_context_t smx_current_context_parallel; #else @@ -29,12 +50,18 @@ static xbt_os_thread_key_t smx_current_context_key = 0; static smx_context_t smx_current_context_serial; static int smx_parallel_contexts = 1; static int smx_parallel_threshold = 2; +static e_xbt_parmap_mode_t smx_parallel_synchronization_mode = XBT_PARMAP_DEFAULT; /** * This function is called by SIMIX_global_init() to initialize the context module. */ void SIMIX_context_mod_init(void) { +#if defined(CONTEXT_THREADS) && !defined(HAVE_THREAD_LOCAL_STORAGE) + /* the __thread storage class is not available on this platform: + * use getspecific/setspecific instead to store the current context in each thread */ + xbt_os_thread_key_create(&smx_current_context_key); +#endif if (!simix_global->context_factory) { /* select the context factory to use to create the contexts */ if (smx_factory_initializer_to_use) { @@ -42,41 +69,32 @@ void SIMIX_context_mod_init(void) } else { /* use the factory specified by --cfg=contexts/factory:value */ - if (smx_context_factory_name == NULL) { - /* use the default factory */ - #ifdef HAVE_RAWCTX - SIMIX_ctx_raw_factory_init(&simix_global->context_factory); - #elif CONTEXT_UCONTEXT - SIMIX_ctx_sysv_factory_init(&simix_global->context_factory); - #else - SIMIX_ctx_thread_factory_init(&simix_global->context_factory); - #endif - } - else if (!strcmp(smx_context_factory_name, "ucontext")) { - /* use ucontext */ + + if (!strcmp(smx_context_factory_name, "thread")) { + /* use os threads (either pthreads or windows ones) */ + SIMIX_ctx_thread_factory_init(&simix_global->context_factory); + } #ifdef CONTEXT_UCONTEXT + else if (!strcmp(smx_context_factory_name, "ucontext")) { + /* use ucontext */ SIMIX_ctx_sysv_factory_init(&simix_global->context_factory); -#else - xbt_die("The context factory 'ucontext' unavailable on your system"); -#endif - } - else if (!strcmp(smx_context_factory_name, "thread")) { - /* use os threads (either pthreads or windows ones) */ - SIMIX_ctx_thread_factory_init(&simix_global->context_factory); } +#endif +#ifdef HAVE_RAWCTX else if (!strcmp(smx_context_factory_name, "raw")) { - /* use raw contexts */ - SIMIX_ctx_raw_factory_init(&simix_global->context_factory); + /* use raw contexts */ + SIMIX_ctx_raw_factory_init(&simix_global->context_factory); } +#endif else { XBT_ERROR("Invalid context factory specified. Valid factories on this machine:"); #ifdef HAVE_RAWCTX XBT_ERROR(" raw: high performance context factory implemented specifically for SimGrid"); #else - XBT_ERROR(" (raw contextes are disabled at compilation time on this machine -- check configure logs for details)"); + XBT_ERROR(" (raw contexts are disabled at compilation time on this machine -- check configure logs for details)"); #endif #ifdef CONTEXT_UCONTEXT - XBT_ERROR(" ucontext: classical system V contextes (implemented with makecontext, swapcontext and friends)"); + XBT_ERROR(" ucontext: classical system V contexts (implemented with makecontext, swapcontext and friends)"); #else XBT_ERROR(" (ucontext is disabled at compilation time on this machine -- check configure logs for details)"); #endif @@ -85,16 +103,10 @@ void SIMIX_context_mod_init(void) } } } - -#if defined(CONTEXT_THREADS) && !defined(HAVE_THREAD_LOCAL_STORAGE) - /* the __thread storage class is not available on this platform: - * use getspecific/setspecific instead to store the current context in each thread */ - xbt_os_thread_key_create(&smx_current_context_key); -#endif } /** - * This function is call by SIMIX_clean() to finalize the context module. + * This function is called by SIMIX_clean() to finalize the context module. */ void SIMIX_context_mod_exit(void) { @@ -105,30 +117,100 @@ void SIMIX_context_mod_exit(void) finalize_factory = simix_global->context_factory->finalize; finalize_factory(&simix_global->context_factory); } - xbt_dict_remove((xbt_dict_t) _surf_cfg_set,"contexts/factory"); + xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory"); } -/** - * \brief Sets the number of parallel threads to use - * for the user contexts. - * - * This function should be called before initializing SIMIX. - * A value of 1 means no parallelism. - * If the value is greater than 1, the thread support must be enabled. - * - * \param nb_threads the number of threads to use - */ -XBT_INLINE void SIMIX_context_set_nthreads(int nb_threads) { +void *SIMIX_context_stack_new(void) +{ + void *stack; - xbt_assert(nb_threads > 0, "Invalid number of parallel threads: %d", nb_threads); + /* FIXME: current code for stack overflow protection assumes that stacks are + * growing downward (PTH_STACKGROWTH == -1). Protected pages need to be put + * after the stack when PTH_STACKGROWTH == 1. */ - if (nb_threads > 1) { -#ifndef CONTEXT_THREADS - THROWF(arg_error, 0, "No thread support for parallel context execution"); + if (smx_context_guard_size > 0 && !MC_is_active()) { + +#if defined(_XBT_WIN32) || (PTH_STACKGROWTH != -1) + static int warned_once = 0; + if (!warned_once) { + XBT_WARN("Stack overflow protection is known to be broken on your system. Either you're on Windows or PTH_STACKGROWTH != -1 (current value is %d).", + PTH_STACKGROWTH); + warned_once = 1; + } +#endif + + size_t size = smx_context_stack_size + smx_context_guard_size; +#ifdef HAVE_MC + /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the + * pointer returned by xbt_malloc0. */ + char *alloc = xbt_malloc0(size + xbt_pagesize); + stack = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize; + *((void **)stack - 1) = alloc; +#elif !defined(_XBT_WIN32) + if (posix_memalign(&stack, xbt_pagesize, size) != 0) + xbt_die("Failed to allocate stack."); +#else + stack = _aligned_malloc(size, xbt_pagesize); +#endif + +#ifndef _XBT_WIN32 + if (mprotect(stack, smx_context_guard_size, PROT_NONE) == -1) { + XBT_WARN("Failed to protect stack: %s", strerror(errno)); + /* That's not fatal, pursue anyway. */ + } #endif + stack = (char *)stack + smx_context_guard_size; + } else { + stack = xbt_malloc0(smx_context_stack_size); } - smx_parallel_contexts = nb_threads; +#ifdef HAVE_VALGRIND_VALGRIND_H + unsigned int valgrind_stack_id = + VALGRIND_STACK_REGISTER(stack, (char *)stack + smx_context_stack_size); + memcpy((char *)stack + smx_context_usable_stack_size, &valgrind_stack_id, + sizeof valgrind_stack_id); +#endif + + return stack; +} + +void SIMIX_context_stack_delete(void *stack) +{ + if (!stack) + return; + +#ifdef HAVE_VALGRIND_VALGRIND_H + unsigned int valgrind_stack_id; + memcpy(&valgrind_stack_id, (char *)stack + smx_context_usable_stack_size, + sizeof valgrind_stack_id); + VALGRIND_STACK_DEREGISTER(valgrind_stack_id); +#endif + +#ifndef WIN32 + if (smx_context_guard_size > 0 && !MC_is_active()) { + stack = (char *)stack - smx_context_guard_size; + if (mprotect(stack, smx_context_guard_size, + PROT_READ | PROT_WRITE | PROT_EXEC) == -1) { + XBT_WARN("Failed to remove page protection: %s", strerror(errno)); + /* try to pursue anyway */ + } +#ifdef HAVE_MC + /* Retrieve the saved pointer. See SIMIX_context_stack_new above. */ + stack = *((void **)stack - 1); +#endif + } +#endif + + xbt_free(stack); +} + +/** + * \brief Returns whether some parallel threads are used + * for the user contexts. + * \return 1 if parallelism is used + */ +XBT_INLINE int SIMIX_context_is_parallel(void) { + return smx_parallel_contexts > 1; } /** @@ -141,38 +223,71 @@ XBT_INLINE int SIMIX_context_get_nthreads(void) { } /** - * \brief Returns whether some parallel threads are used + * \brief Sets the number of parallel threads to use * for the user contexts. - * \return 1 if parallelism is used + * + * This function should be called before initializing SIMIX. + * A value of 1 means no parallelism (1 thread only). + * If the value is greater than 1, the thread support must be enabled. + * + * \param nb_threads the number of threads to use */ -XBT_INLINE int SIMIX_context_is_parallel(void) { - return smx_parallel_contexts > 1; +void SIMIX_context_set_nthreads(int nb_threads) { + if (nb_threads<=0) { + nb_threads = xbt_os_get_numcores(); + XBT_INFO("Auto-setting contexts/nthreads to %d",nb_threads); + } + + if (nb_threads > 1) { +#ifndef CONTEXT_THREADS + THROWF(arg_error, 0, "The thread factory cannot be run in parallel"); +#endif + } + smx_parallel_contexts = nb_threads; } /** - * \brief Sets the threshold above which user processes are run in parallel. + * \brief Returns the threshold above which user processes are run in parallel. * * If the number of threads is set to 1, there is no parallelism and this * threshold has no effect. * - * \param threshold when the number of user processes ready to run is above + * \return when the number of user processes ready to run is above * this threshold, they are run in parallel */ -XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) { - smx_parallel_threshold = threshold; +XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { + return smx_parallel_threshold; } /** - * \brief Returns the threshold above which user processes are run in parallel. + * \brief Sets the threshold above which user processes are run in parallel. * * If the number of threads is set to 1, there is no parallelism and this * threshold has no effect. * - * \return when the number of user processes ready to run is above + * \param threshold when the number of user processes ready to run is above * this threshold, they are run in parallel */ -XBT_INLINE int SIMIX_context_get_parallel_threshold(void) { - return smx_parallel_threshold; +XBT_INLINE void SIMIX_context_set_parallel_threshold(int threshold) { + smx_parallel_threshold = threshold; +} + +/** + * \brief Returns the synchronization mode used when processes are run in + * parallel. + * \return how threads are synchronized if processes are run in parallel + */ +XBT_INLINE e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode(void) { + return smx_parallel_synchronization_mode; +} + +/** + * \brief Sets the synchronization mode to use when processes are run in + * parallel. + * \param mode how to synchronize threads if processes are run in parallel + */ +XBT_INLINE void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) { + smx_parallel_synchronization_mode = mode; } /** @@ -210,4 +325,3 @@ XBT_INLINE void SIMIX_context_set_current(smx_context_t context) smx_current_context_serial = context; } } -