diff options
| -rw-r--r-- | src/rt/arch/i386/context.h | 6 | ||||
| -rw-r--r-- | src/rt/arch/x86_64/context.h | 6 | ||||
| -rw-r--r-- | src/rt/rust_task.cpp | 39 | ||||
| -rw-r--r-- | src/rt/rust_task.h | 11 | ||||
| -rw-r--r-- | src/rt/rust_task_thread.cpp | 58 | ||||
| -rw-r--r-- | src/rt/rust_task_thread.h | 4 |
6 files changed, 96 insertions, 28 deletions
diff --git a/src/rt/arch/i386/context.h b/src/rt/arch/i386/context.h index 71cd7aeada2..ae65cdb5813 100644 --- a/src/rt/arch/i386/context.h +++ b/src/rt/arch/i386/context.h @@ -29,8 +29,6 @@ struct registers_t { uint32_t eip; } __attribute__((aligned(16))); -extern "C" void __morestack(void *args, void *fn_ptr, uintptr_t stack_ptr); - class context { public: registers_t regs; @@ -41,10 +39,6 @@ public: void swap(context &out); void call(void *f, void *arg, void *sp); - - void call_and_change_stacks(void *args, void *fn_ptr) { - __morestack(args, fn_ptr, regs.esp); - } }; #endif diff --git a/src/rt/arch/x86_64/context.h b/src/rt/arch/x86_64/context.h index 2b9b5d4c6c7..412d968599f 100644 --- a/src/rt/arch/x86_64/context.h +++ b/src/rt/arch/x86_64/context.h @@ -28,8 +28,6 @@ struct registers_t { uint64_t data[RUSTRT_MAX]; } __attribute__((aligned(16))); -extern "C" void __morestack(void *args, void *fn_ptr, uintptr_t stack_ptr); - class context { public: registers_t regs; @@ -40,10 +38,6 @@ public: void swap(context &out); void call(void *f, void *arg, void *sp); - - void call_and_change_stacks(void *args, void *fn_ptr) { - __morestack(args, fn_ptr, regs.data[RUSTRT_RSP]); - } }; #endif diff --git a/src/rt/rust_task.cpp b/src/rt/rust_task.cpp index 912225fba3f..a025800e4ae 100644 --- a/src/rt/rust_task.cpp +++ b/src/rt/rust_task.cpp @@ -88,7 +88,9 @@ rust_task::rust_task(rust_task_thread *thread, rust_task_list *state, propagate_failure(true), dynastack(this), cc_counter(0), - total_stack_sz(0) + total_stack_sz(0), + c_stack(NULL), + next_c_sp(0) { LOGPTR(thread, "new task", (uintptr_t)this); DLOG(thread, task, "sizeof(task) = %d (0x%x)", sizeof *this, sizeof *this); @@ -166,7 +168,6 @@ cleanup_task(cleanup_args *args) { } // This runs on the Rust stack -extern "C" CDECL void task_start_wrapper(spawn_args *a) { rust_task *task = a->task; @@ -180,8 +181,15 @@ void task_start_wrapper(spawn_args *a) A(task->thread, ex == task, "Expected this task to be thrown for unwinding"); threw_exception = true; + + if (task->c_stack) { + task->return_c_stack(); + } } + // We should have returned any C stack by now + I(task->thread, task->c_stack == NULL); + rust_opaque_box* env = a->envptr; if(env) { // free the environment (which should be a unique closure). @@ -722,10 +730,35 @@ rust_task::config_notify(chan_handle chan) { notify_chan = chan; } +extern "C" void __morestack(void *args, void *fn_ptr, uintptr_t stack_ptr); + void rust_task::call_on_c_stack(void *args, void *fn_ptr) { I(thread, on_rust_stack()); - thread->c_context.call_and_change_stacks(args, fn_ptr); + + bool borrowed_a_c_stack = false; + if (c_stack == NULL) { + c_stack = thread->borrow_c_stack(); + next_c_sp = align_down(c_stack->end); + borrowed_a_c_stack = true; + } + + __morestack(args, fn_ptr, next_c_sp); + + // Note that we may not actually get here if we threw an exception, + // in which case we will return the c stack when the exception is caught. + if (borrowed_a_c_stack) { + return_c_stack(); + } +} + +void +rust_task::return_c_stack() { + I(thread, on_rust_stack()); + I(thread, c_stack != NULL); + thread->return_c_stack(c_stack); + c_stack = NULL; + next_c_sp = 0; } // diff --git a/src/rt/rust_task.h b/src/rt/rust_task.h index c4939d208c1..5ac2d7a212e 100644 --- a/src/rt/rust_task.h +++ b/src/rt/rust_task.h @@ -36,6 +36,8 @@ typedef unsigned long task_result; #define tr_success 0 #define tr_failure 1 +struct spawn_args; + // std::lib::task::task_notification // // since it's currently a unary tag, we only add the fields. @@ -104,6 +106,11 @@ rust_task : public kernel_owned<rust_task>, rust_cond size_t total_stack_sz; private: + + // The stack used for running C code, borrowed from the scheduler thread + stk_seg *c_stack; + uintptr_t next_c_sp; + // Called when the atomic refcount reaches zero void delete_this(); @@ -112,6 +119,10 @@ private: void free_stack(stk_seg *stk); size_t get_next_stack_size(size_t min, size_t current, size_t requested); + void return_c_stack(); + + friend void task_start_wrapper(spawn_args *a); + public: // Only a pointer to 'name' is kept, so it must live as long as this task. diff --git a/src/rt/rust_task_thread.cpp b/src/rt/rust_task_thread.cpp index 4129969057c..48bd7f16bdf 100644 --- a/src/rt/rust_task_thread.cpp +++ b/src/rt/rust_task_thread.cpp @@ -61,10 +61,6 @@ rust_task_thread::~rust_task_thread() { #ifndef __WIN32__ pthread_attr_destroy(&attr); #endif - - if (cached_c_stack) { - destroy_stack(kernel, cached_c_stack); - } } void @@ -72,7 +68,9 @@ rust_task_thread::activate(rust_task *task) { task->ctx.next = &c_context; DLOG(this, task, "descheduling..."); lock.unlock(); + prepare_c_stack(); task->ctx.swap(c_context); + unprepare_c_stack(); lock.lock(); DLOG(this, task, "task has returned"); } @@ -287,6 +285,13 @@ rust_task_thread::start_main_loop() { DLOG(this, dom, "finished main-loop %d", id); lock.unlock(); + + I(this, !extra_c_stack); + if (cached_c_stack) { + unconfig_valgrind_stack(cached_c_stack); + destroy_stack(kernel, cached_c_stack); + cached_c_stack = NULL; + } } rust_crate_cache * @@ -374,24 +379,51 @@ rust_task_thread::exit() { lock.signal(); } +// Before activating each task, make sure we have a C stack available. +// It needs to be allocated ahead of time (while we're on our own +// stack), because once we're on the Rust stack we won't have enough +// room to do the allocation +void +rust_task_thread::prepare_c_stack() { + I(this, !extra_c_stack); + if (!cached_c_stack) { + cached_c_stack = create_stack(kernel, C_STACK_SIZE); + } +} + +void +rust_task_thread::unprepare_c_stack() { + if (extra_c_stack) { + destroy_stack(kernel, extra_c_stack); + extra_c_stack = NULL; + } +} + +// NB: Runs on the Rust stack stk_seg * rust_task_thread::borrow_c_stack() { - - if (cached_c_stack) { - stk_seg *your_stack = cached_c_stack; - cached_c_stack = NULL; - return your_stack; + I(this, cached_c_stack); + stk_seg *your_stack; + if (extra_c_stack) { + your_stack = extra_c_stack; + extra_c_stack = NULL; } else { - return create_stack(kernel, C_STACK_SIZE); + your_stack = cached_c_stack; + cached_c_stack = NULL; } + config_valgrind_stack(your_stack); + return your_stack; } +// NB: Runs on the Rust stack void rust_task_thread::return_c_stack(stk_seg *stack) { - if (cached_c_stack) { - destroy_stack(kernel, stack); - } else { + I(this, !extra_c_stack); + unconfig_valgrind_stack(stack); + if (!cached_c_stack) { cached_c_stack = stack; + } else { + extra_c_stack = stack; } } diff --git a/src/rt/rust_task_thread.h b/src/rt/rust_task_thread.h index 360e4e44e0b..82609bc887a 100644 --- a/src/rt/rust_task_thread.h +++ b/src/rt/rust_task_thread.h @@ -95,6 +95,10 @@ struct rust_task_thread : public kernel_owned<rust_task_thread>, private: stk_seg *cached_c_stack; + stk_seg *extra_c_stack; + + void prepare_c_stack(); + void unprepare_c_stack(); public: |