- void *stack;
-
- /* 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 (smx_context_guard_size > 0 && !MC_is_active()) {
-
-#if !defined(PTH_STACKGROWTH) || (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 stack grows upwards, or it was not even tested properly.");
- warned_once = 1;
- }
-#endif
-
- size_t size = smx_context_stack_size + smx_context_guard_size;
-#if HAVE_MC
- /* Cannot use posix_memalign when HAVE_MC. Align stack by hand, and save the
- * pointer returned by xbt_malloc0. */
- char *alloc = (char*)xbt_malloc0(size + xbt_pagesize);
- stack = alloc - ((uintptr_t)alloc & (xbt_pagesize - 1)) + xbt_pagesize;
- *((void **)stack - 1) = alloc;
-#elif !defined(_WIN32)
- if (posix_memalign(&stack, xbt_pagesize, size) != 0)
- xbt_die("Failed to allocate stack.");
-#else
- stack = _aligned_malloc(size, xbt_pagesize);
-#endif
-
-#ifndef _WIN32
- if (mprotect(stack, smx_context_guard_size, PROT_NONE) == -1) {
- xbt_die("Failed to protect stack %p: %s", stack, strerror(errno));
- /* This is fatal. We are going to fail at some point when we try reusing this. */
- }
-#endif
- stack = (char *)stack + smx_context_guard_size;
- } else {
- stack = xbt_malloc0(smx_context_stack_size);
- }
-
-#if HAVE_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;
-
-#if HAVE_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) == -1) {
- XBT_WARN("Failed to remove page protection: %s", strerror(errno));
- /* try to pursue anyway */
- }
-#if HAVE_MC
- /* Retrieve the saved pointer. See SIMIX_context_stack_new above. */
- stack = *((void **)stack - 1);
-#endif
- }
-#endif /* not windows */
-
- xbt_free(stack);
-}
-
-/** @brief Returns whether some parallel threads are used for the user contexts. */
-int SIMIX_context_is_parallel() {
- return smx_parallel_contexts > 1;
-}
-
-/**
- * @brief Returns the number of parallel threads used for the user contexts.
- * \return the number of threads (1 means no parallelism)
- */
-int SIMIX_context_get_nthreads() {
- return smx_parallel_contexts;
-}
-
-/**
- * \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 (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
- */
-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 !HAVE_THREAD_CONTEXTS
- xbt_assert(nb_threads == 1, "Parallel runs are impossible when the pthreads are missing.");
-#endif
- smx_parallel_contexts = nb_threads;
-}
-
-/**
- * \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.
- *
- * \return when the number of user processes ready to run is above
- * this threshold, they are run in parallel
- */
-int SIMIX_context_get_parallel_threshold() {
- return smx_parallel_threshold;
-}
-
-/**
- * \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.
- *
- * \param threshold when the number of user processes ready to run is above
- * this threshold, they are run in parallel
- */
-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
- */
-e_xbt_parmap_mode_t SIMIX_context_get_parallel_mode() {
- 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
- */
-void SIMIX_context_set_parallel_mode(e_xbt_parmap_mode_t mode) {
- smx_parallel_synchronization_mode = mode;