-/* Copyright (c) 2009-2018. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2009-2019. 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. */
XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(simix_context);
-/** Many integers are needed to store a pointer
- *
- * Support up to two ints. */
+/** Up to two integers may be needed to store a pointer on the system we target */
constexpr int CTX_ADDR_LEN = 2;
static_assert(sizeof(simgrid::kernel::context::UContext*) <= CTX_ADDR_LEN * sizeof(int),
- "Ucontexts are not supported on this arch yet");
+ "Ucontexts are not supported on this arch yet. Please increase CTX_ADDR_LEN.");
namespace simgrid {
namespace kernel {
namespace context {
-// UContextFactory
-Context* UContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup, smx_actor_t process)
-{
- return new_context<UContext>(std::move(code), cleanup, process, this);
-}
-
-
-// UContext
-
-UContext::UContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t process,
- SwappedContextFactory* factory)
- : SwappedContext(std::move(code), cleanup_func, process, factory)
-{
- /* if the user provided a function for the process then use it, otherwise it is the context for maestro */
- if (has_code()) {
- getcontext(&this->uc_);
- this->uc_.uc_link = nullptr;
- this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(this->stack_);
- this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_usable_stack_size);
-#if PTH_STACKGROWTH == -1
- ASAN_ONLY(this->asan_stack_ = static_cast<char*>(this->stack_) + smx_context_usable_stack_size);
-#else
- ASAN_ONLY(this->asan_stack_ = this->stack_);
-#endif
- UContext::make_ctx(&this->uc_, UContext::smx_ctx_sysv_wrapper, this);
- } else {
- if (process != nullptr && get_maestro() == nullptr)
- set_maestro(this);
- }
-
-#if SIMGRID_HAVE_MC
- if (MC_is_active() && has_code()) {
- MC_register_stack_area(this->stack_, process, &(this->uc_), smx_context_usable_stack_size);
- }
-#endif
-}
-
-UContext::~UContext() = default;
-
-// The name of this function is currently hardcoded in the code (as string).
+// The name of this function is currently hardcoded in MC (as string).
// Do not change it without fixing those references as well.
-void UContext::smx_ctx_sysv_wrapper(int i1, int i2)
+static void smx_ctx_wrapper(int i1, int i2)
{
// Rebuild the Context* pointer from the integers:
int ctx_addr[CTX_ADDR_LEN] = {i1, i2};
context->suspend();
}
-/** A better makecontext
- *
- * Makecontext expects integer arguments, we the context variable is decomposed into a serie of integers and each
- * integer is passed as argument to makecontext.
- */
-void UContext::make_ctx(ucontext_t* ucp, void (*func)(int, int), UContext* arg)
+// UContextFactory
+Context* UContextFactory::create_context(std::function<void()> code, void_pfn_smxprocess_t cleanup, smx_actor_t actor)
+{
+ return new_context<UContext>(std::move(code), cleanup, actor, this);
+}
+
+
+// UContext
+
+UContext::UContext(std::function<void()> code, void_pfn_smxprocess_t cleanup_func, smx_actor_t actor,
+ SwappedContextFactory* factory)
+ : SwappedContext(std::move(code), cleanup_func, actor, factory)
{
- int ctx_addr[CTX_ADDR_LEN]{};
- memcpy(ctx_addr, &arg, sizeof arg);
- makecontext(ucp, (void (*)())func, 2, ctx_addr[0], ctx_addr[1]);
+ /* if the user provided a function for the actor then use it. If not, nothing to do for maestro. */
+ if (has_code()) {
+ getcontext(&this->uc_);
+ this->uc_.uc_link = nullptr;
+ this->uc_.uc_stack.ss_sp = sg_makecontext_stack_addr(get_stack());
+ this->uc_.uc_stack.ss_size = sg_makecontext_stack_size(smx_context_usable_stack_size);
+#if PTH_STACKGROWTH == -1
+ ASAN_ONLY(this->asan_stack_ = static_cast<char*>(get_stack()) + smx_context_usable_stack_size);
+#else
+ ASAN_ONLY(this->asan_stack_ = get_stack());
+#endif
+ // Makecontext expects integer arguments; we want to pass a pointer.
+ // This context address is decomposed into a serie of integers, which are passed as arguments to makecontext.
+
+ int ctx_addr[CTX_ADDR_LEN]{};
+ UContext* arg = this;
+ memcpy(ctx_addr, &arg, sizeof this);
+ makecontext(&this->uc_, (void (*)())smx_ctx_wrapper, 2, ctx_addr[0], ctx_addr[1]);
+ }
+
+#if SIMGRID_HAVE_MC
+ if (MC_is_active() && has_code()) {
+ MC_register_stack_area(get_stack(), actor, &(this->uc_), smx_context_usable_stack_size);
+ }
+#endif
}
void UContext::swap_into(SwappedContext* to_)
{
UContext* to = static_cast<UContext*>(to_);
ASAN_ONLY(void* fake_stack = nullptr);
- ASAN_ONLY(to->asan_ctx_ = from);
- ASAN_START_SWITCH(from->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
+ ASAN_ONLY(to->asan_ctx_ = this);
+ ASAN_START_SWITCH(this->asan_stop_ ? nullptr : &fake_stack, to->asan_stack_, to->asan_stack_size_);
swapcontext(&this->uc_, &to->uc_);
- ASAN_FINISH_SWITCH(fake_stack, &from->asan_ctx_->asan_stack_, &from->asan_ctx_->asan_stack_size_);
+ ASAN_FINISH_SWITCH(fake_stack, &this->asan_ctx_->asan_stack_, &this->asan_ctx_->asan_stack_size_);
}
