/* a fast and simple context switching library */
-/* Copyright (c) 2009 - 2011. 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
#include "smx_private.h"
#include "simgrid/sg_config.h"
#include "internal_config.h"
+#include "simgrid/modelchecker.h"
+#include <sys/mman.h>
+
+#ifdef HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+#endif
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
"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
}
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
xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory");
}
+void *SIMIX_context_stack_new(void)
+{
+ void *stack;
+
+ if (smx_context_guard_size > 0 && !MC_is_active()) {
+ 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;
+#else
+ if (posix_memalign(&stack, xbt_pagesize, size) != 0)
+ xbt_die("Failed to allocate stack.");
+#endif
+ 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. */
+ }
+ stack = (char *)stack + smx_context_guard_size;
+ } else {
+ stack = xbt_malloc0(smx_context_stack_size);
+ }
+
+#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
+
+ 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
+ }
+ xbt_free(stack);
+}
+
/**
* \brief Returns whether some parallel threads are used
* for the user contexts.
*
* \param nb_threads the number of threads to use
*/
-XBT_INLINE void SIMIX_context_set_nthreads(int nb_threads) {
+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);
smx_current_context_serial = context;
}
}
-
