/* a fast and simple context switching library */
-/* Copyright (c) 2009-2014. 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
#include "smx_private.h"
#include "simgrid/sg_config.h"
#include "internal_config.h"
+#include "simgrid/modelchecker.h"
+
+
+#ifdef _WIN32
+#include <windows.h>
+#include <malloc.h>
+#else
+#include <sys/mman.h>
+#endif
+
+#ifdef __MINGW32__
+#define _aligned_malloc __mingw_aligned_malloc
+#define _aligned_free __mingw_aligned_free
+#endif //MINGW
+
+#ifdef HAVE_VALGRIND_VALGRIND_H
+# include <valgrind/valgrind.h>
+#endif
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_context, simix,
"Context switching mechanism");
smx_ctx_factory_initializer_t smx_factory_initializer_to_use = NULL;
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;
+static XBT_THREAD_LOCAL smx_context_t smx_current_context_parallel;
#else
static xbt_os_thread_key_t smx_current_context_key = 0;
#endif
/* use raw contexts */
SIMIX_ctx_raw_factory_init(&simix_global->context_factory);
}
+#endif
+#ifdef HAVE_BOOST_CONTEXT
+ else if (!strcmp(smx_context_factory_name, "boost")) {
+ /* use Boost.Context */
+ SIMIX_ctx_boost_factory_init(&simix_global->context_factory);
+ }
#endif
else {
XBT_ERROR("Invalid context factory specified. Valid factories on this machine:");
xbt_dict_remove((xbt_dict_t) _sg_cfg_set,"contexts/factory");
}
+void *SIMIX_context_stack_new(void)
+{
+ 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(_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_die("Failed to protect stack: %s", strerror(errno));
+ /* This is fatal. We are going to fail at some point when
+ we tryi reusing this. */
+ }
+#endif
+ 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
+
+#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 */
+ }
+#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.