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This is the mega-ucontext commit. It replaces the task switching mechanism with a new one inspired by ucontext. It works under Linux, OS X and Windows, and is Valgrind clean on Linux and OS X (provided the runtime is built with gcc). 

This commit also moves yield and join to the standard library, as requested in #42. Join is currently a no-op though.
This commit is contained in:
Eric Holk 2011-05-31 17:44:54 -07:00 committed by Graydon Hoare
parent 1595c9d767
commit d1857d30fc
30 changed files with 419 additions and 443 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
configure vendored
View File

@ -176,11 +176,11 @@ fi
step_msg "making directories"
for i in \
doc \
rt rt/isaac rt/bigint rt/sync rt/test \
rt rt/isaac rt/bigint rt/sync rt/test rt/arch/i386 \
rustllvm \
dl stage0 stage1 stage2 stage3 \
test/run-pass test/run-fail test/compile-fail \
test/bench/99-bottles test/bench/shootout
test/bench/99-bottles test/bench/shootout
do
make_dir $i
done

13
mk/rt.mk
View File

@ -27,11 +27,12 @@ RUNTIME_CS := rt/sync/timer.cpp \
rt/memory_region.cpp \
rt/test/rust_test_harness.cpp \
rt/test/rust_test_runtime.cpp \
rt/test/rust_test_util.cpp
rt/test/rust_test_util.cpp \
rt/arch/i386/context.cpp \
RUNTIME_LL := rt/new_exit.ll rt/vec_append.ll
RUNTIME_LL := rt/vec_append.ll
RUNTIME_S := rt/activate_glue.s rt/yield_glue.s
RUNTIME_S := rt/arch/i386/_context.s
RUNTIME_HDR := rt/globals.h \
rt/rust.h \
@ -60,10 +61,12 @@ RUNTIME_HDR := rt/globals.h \
rt/memory.h \
rt/test/rust_test_harness.h \
rt/test/rust_test_runtime.h \
rt/test/rust_test_util.h
rt/test/rust_test_util.h \
rt/arch/i386/context.h \
RUNTIME_DEF := rt/rustrt$(CFG_DEF_SUFFIX)
RUNTIME_INCS := -I $(S)src/rt/isaac -I $(S)src/rt/uthash
RUNTIME_INCS := -I $(S)src/rt/isaac -I $(S)src/rt/uthash \
-I $(S)src/rt/arch/i386
RUNTIME_OBJS := $(RUNTIME_CS:.cpp=.o) $(RUNTIME_LL:.ll=.o) $(RUNTIME_S:.s=.o)
RUNTIME_LIBS := $(CFG_GCCISH_POST_LIB_FLAGS)

4
src/comp/back/abi.rs
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@ -93,10 +93,6 @@ fn vec_append_glue_name() -> str {
ret "rust_vec_append_glue";
}
fn yield_glue_name() -> str {
ret "rust_yield_glue";
}
fn no_op_type_glue_name() -> str {
ret "rust_no_op_type_glue";
}

2
src/comp/back/upcall.rs
View File

@ -114,7 +114,7 @@ fn declare_upcalls(type_names tn, ModuleRef llmod) -> @upcalls {
T_ptr(T_tydesc(tn))),
new_task=d("new_task", [T_ptr(T_str())], T_taskptr(tn)),
start_task=d("start_task", [T_taskptr(tn),
T_int(), T_int()],
T_int(), T_int(), T_size_t()],
T_taskptr(tn)),
new_thread=d("new_thread", [T_ptr(T_i8())], T_taskptr(tn)),
start_thread=d("start_thread", [T_taskptr(tn), T_int(), T_int(),

11
src/comp/middle/trans.rs
View File

@ -85,8 +85,7 @@ state obj namegen(mutable int i) {
type derived_tydesc_info = rec(ValueRef lltydesc, bool escapes);
type glue_fns = rec(ValueRef yield_glue,
ValueRef no_op_type_glue,
type glue_fns = rec(ValueRef no_op_type_glue,
ValueRef vec_append_glue);
type tydesc_info = rec(ty::t ty,
@ -6454,13 +6453,12 @@ fn trans_spawn(&@block_ctxt cx,
auto wrapper = mk_spawn_wrapper(bcx, func, args_ty);
bcx = wrapper.bcx;
auto llfnptr_i = bcx.build.PointerCast(wrapper.val, T_int());
// TODO: this next line might be necessary...
//llfnptr_i = bcx.build.Load(llfnptr_i);
// And start the task
auto args_size = size_of(bcx, args_ty).val;
bcx.build.Call(bcx.fcx.lcx.ccx.upcalls.start_task,
[bcx.fcx.lltaskptr, new_task,
llfnptr_i, llargs_i]);
llfnptr_i, llargs_i, args_size]);
auto task_ty = node_ann_type(bcx.fcx.lcx.ccx, ann);
auto dropref = clean(bind drop_ty(_, new_task, task_ty));
@ -8545,8 +8543,7 @@ fn vec_p0(&@block_ctxt bcx, ValueRef v) -> ValueRef {
}
fn make_glues(ModuleRef llmod, &type_names tn) -> @glue_fns {
ret @rec(yield_glue = decl_glue(llmod, tn, abi::yield_glue_name()),
no_op_type_glue = decl_no_op_type_glue(llmod, tn),
ret @rec(no_op_type_glue = decl_no_op_type_glue(llmod, tn),
vec_append_glue = make_vec_append_glue(llmod, tn));
}

4
src/lib/std.rc
View File

@ -18,7 +18,7 @@ mod str;
mod io;
mod sys;
mod _task;
mod task;
// Utility modules.
@ -33,7 +33,7 @@ auth os_fs = unsafe;
auth run = unsafe;
auth str = unsafe;
auth vec = unsafe;
auth _task = unsafe;
auth task = unsafe;
auth dbg = unsafe;

10
src/lib/_task.rs → src/lib/task.rs
View File

@ -1,5 +1,6 @@
native "rust" mod rustrt {
fn task_sleep(uint time_in_us);
fn task_yield();
}
/**
@ -11,6 +12,15 @@ fn sleep(uint time_in_us) {
ret rustrt::task_sleep(time_in_us);
}
fn yield() {
ret rustrt::task_yield();
}
fn join(task t) {
// TODO: figure out how to pass tasks to the runtime and call the builtin
// join.
}
// Local Variables:
// mode: rust;
// fill-column: 78;

89
src/rt/activate_glue.s
View File

@ -1,89 +0,0 @@
/*
* This is a bit of glue-code.
*
* - save regs on C stack
* - save sp to task.runtime_sp (runtime_sp is thus always aligned)
* - load saved task sp (switch stack)
* - restore saved task regs
* - return to saved task pc
*
* Our incoming stack looks like this:
*
* *esp+4 = [arg1 ] = task ptr
* *esp = [retpc ]
*/
.globl new_rust_activate_glue
.balign 4
new_rust_activate_glue:
movl 4(%esp), %ecx # ecx = rust_task
pushl %ebp
pushl %edi
pushl %esi
pushl %ebx
movl %esp, 12(%ecx)
movl 16(%ecx), %esp
/*
* There are two paths we can arrive at this code from:
*
*
* 1. We are activating a task for the first time. When we switch
* into the task stack and 'ret' to its first instruction, we'll
* start doing whatever the first instruction says. Probably
* saving registers and starting to establish a frame. Harmless
* stuff, doesn't look at task->rust_sp again except when it
* clobbers it during a later native call.
*
*
* 2. We are resuming a task that was descheduled by the yield glue
* below. When we switch into the task stack and 'ret', we'll be
* ret'ing to a very particular instruction:
*
* "esp <- task->rust_sp"
*
* this is the first instruction we 'ret' to after this glue,
* because it is the first instruction following *any* native
* call, and the task we are activating was descheduled
* mid-native-call.
*
* Unfortunately for us, we have already restored esp from
* task->rust_sp and are about to eat the 5 words off the top of
* it.
*
*
* | ... | <-- where esp will be once we restore + ret, below,
* | retpc | and where we'd *like* task->rust_sp to wind up.
* | ebp |
* | edi |
* | esi |
* | ebx | <-- current task->rust_sp == current esp
*
*
* This is a problem. If we return to "esp <- task->rust_sp" it
* will push esp back down by 5 words. This manifests as a rust
* stack that grows by 5 words on each yield/reactivate. Not
* good.
*
* So what we do here is just adjust task->rust_sp up 5 words as
* well, to mirror the movement in esp we're about to
* perform. That way the "esp <- task->rust_sp" we 'ret' to below
* will be a no-op. Esp won't move, and the task's stack won't
* grow.
*/
addl $20, 16(%ecx)
/*
* In most cases, the function we're returning to (activating)
* will have saved any caller-saves before it yielded via native call,
* so no work to do here. With one exception: when we're initially
* activating, the task needs to be in the fastcall 2nd parameter
* expected by the rust main function. That's edx.
*/
mov %ecx, %edx
popl %ebx
popl %esi
popl %edi
popl %ebp
ret

86
src/rt/arch/i386/_context.s Normal file
View File

@ -0,0 +1,86 @@
.text
/*
Callee save registers:
ebp, ebx, esi, edi
Caller save registers:
eax, ecx, edx
*/
/*
Saves a set of registers. This is used by our implementation of
getcontext.
The registers_t variable is in (%esp)
*/
.globl get_registers
get_registers:
movl 4(%esp), %eax
movl %eax, 0(%eax)
movl %ebx, 4(%eax)
movl %ecx, 8(%eax)
movl %edx, 12(%eax)
movl %ebp, 16(%eax)
movl %esi, 20(%eax)
movl %edi, 24(%eax)
movl %esp, 28(%eax)
movw %cs, 32(%eax)
movw %ds, 34(%eax)
movw %ss, 36(%eax)
movw %es, 38(%eax)
movw %fs, 40(%eax)
movw %gs, 42(%eax)
// save the flags
pushf
popl %ecx
movl %ecx, 44(%eax)
// save the return address as the instruction pointer
movl 0(%esp), %ecx
movl %ecx, 48(%eax)
// return 0
xor %eax, %eax
ret
.globl set_registers
set_registers:
movl 4(%esp), %eax
movl 4(%eax), %ebx
// save ecx for later...
movl 12(%eax), %edx
movl 16(%eax), %ebp
movl 20(%eax), %esi
movl 24(%eax), %edi
movl 28(%eax), %esp
// We can't actually change this...
//movl 32(%eax), %cs
movw 34(%eax), %ds
movw 36(%eax), %ss
movw 38(%eax), %es
movw 40(%eax), %fs
movw 42(%eax), %gs
// restore the flags
movl 44(%eax), %ecx
push %ecx
popf
// get ready to return back to the old eip
// We could write this directly to 0(%esp), but Valgrind on OS X
// complains.
pop %ecx
mov 48(%eax), %ecx
push %ecx
//movl %ecx, 0(%esp)
// okay, now we can restore ecx.
movl 8(%eax), %ecx
// return 1 to the saved eip
movl $1, %eax
ret

81
src/rt/arch/i386/context.cpp Normal file
View File

@ -0,0 +1,81 @@
#include "context.h"
#include "../../rust.h"
#include <stdio.h>
#include <stdlib.h>
extern "C" uint32_t CDECL get_registers(registers_t *regs)
asm ("get_registers");
extern "C" uint32_t CDECL set_registers(registers_t *regs)
asm ("set_registers");
context::context()
: next(NULL)
{
get_registers(&regs);
}
void context::set()
{
//printf("Activating %p...\n", this);
set_registers(&regs);
}
void context::swap(context &out)
{
//printf("Swapping to %p and saving in %p\n", this, &out);
uint32_t r = get_registers(&out.regs);
//printf("get_registers = %d, sp = 0x%x\n", r, out.regs.esp);
if(!r) {
set();
}
//printf("Resumed %p...\n", &out);
}
void context::call(void *f, void *arg, void *stack) {
// set up the trampoline frame
uint32_t *sp = (uint32_t *)stack;
*--sp = (uint32_t)this;
*--sp = (uint32_t)arg;
*--sp = 0xdeadbeef; //(uint32_t)ctx_trampoline1;
*--sp = 0xdeadbeef;
regs.esp = (uint32_t)sp;
regs.eip = (uint32_t)f;
}
#if 0
// This is some useful code to check how the registers struct got
// layed out in memory.
int main() {
registers_t regs;
printf("Register offsets\n");
#define REG(r) \
printf(" %6s: +%ld\n", #r, (intptr_t)&regs.r - (intptr_t)&regs);
REG(eax);
REG(ebx);
REG(ecx);
REG(edx);
REG(ebp);
REG(esi);
REG(edi);
REG(esp);
REG(cs);
REG(ds);
REG(ss);
REG(es);
REG(fs);
REG(gs);
REG(eflags);
REG(eip);
return 0;
}
#endif

35
src/rt/arch/i386/context.h Normal file
View File

@ -0,0 +1,35 @@
// -*- mode: c++ -*-
#ifndef CONTEXT_H
#define CONTEXT_H
#include <inttypes.h>
struct registers_t {
// general purpose registers
uint32_t eax, ebx, ecx, edx, ebp, esi, edi, esp;
// segment registers
uint16_t cs, ds, ss, es, fs, gs;
uint32_t eflags;
uint32_t eip;
};
class context {
registers_t regs;
public:
context();
context *next;
void set();
void swap(context &out);
void call(void *f, void *arg, void *sp);
};
#endif

15
src/rt/globals.h
View File

@ -1,9 +1,12 @@
#ifndef GLOBALS_H
#define GLOBALS_H
#ifndef RUST_INTERNAL_H
// these are defined in two files and GCC complains
#define __STDC_LIMIT_MACROS 1
#define __STDC_CONSTANT_MACROS 1
#define __STDC_FORMAT_MACROS 1
#endif
#include <stdlib.h>
#include <stdint.h>
@ -32,4 +35,16 @@ extern "C" {
#error "Platform not supported."
#endif
#define CHECKED(call) \
{ \
int res = (call); \
if(0 != res) { \
fprintf(stderr, \
#call " failed in %s at line %d, result = %d " \
"(%s) \n", \
__FILE__, __LINE__, res, strerror(res)); \
abort(); \
} \
}
#endif /* GLOBALS_H */

43
src/rt/new_exit.ll
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@ -1,43 +0,0 @@
declare fastcc i32 @"\01rust_native_rust_local_copy"(i32, i32)
module asm "\09.globl rust_native_rust_local_copy"
module asm "\09.balign 4"
module asm "rust_native_rust_local_copy:"
module asm "\09.cfi_startproc"
module asm "\09pushl %ebp"
module asm "\09.cfi_def_cfa_offset 8"
module asm "\09.cfi_offset %ebp, -8"
module asm "\09pushl %edi"
module asm "\09.cfi_def_cfa_offset 12"
module asm "\09pushl %esi"
module asm "\09.cfi_def_cfa_offset 16"
module asm "\09pushl %ebx"
module asm "\09.cfi_def_cfa_offset 20"
module asm "\09movl %esp, %ebp # ebp = rust_sp"
module asm "\09.cfi_def_cfa_register %ebp"
module asm "\09movl %esp, 16(%edx)"
module asm "\09movl 12(%edx), %esp"
module asm "\09subl $4, %esp # esp -= args"
module asm "\09andl $~0xf, %esp # align esp down"
module asm "\09movl %edx, (%esp)"
module asm "\09movl %edx, %edi # save task from edx to edi"
module asm "\09call *%ecx # call *%ecx"
module asm "\09movl %edi, %edx # restore edi-saved task to edx"
module asm "\09movl 16(%edx), %esp"
module asm "\09popl %ebx"
module asm "\09popl %esi"
module asm "\09popl %edi"
module asm "\09popl %ebp"
module asm "\09ret"
module asm "\09.cfi_endproc"
declare i32 @upcall_exit(i32)
define void @rust_new_exit_task_glue(i32, i32, i32, i32, i32) {
entry:
%5 = inttoptr i32 %0 to void (i32, i32, i32, i32)*
tail call fastcc void %5(i32 %1, i32 %2, i32 %3, i32 %4)
%6 = tail call fastcc i32 @"\01rust_native_rust_local_copy"(i32 ptrtoint (i32 (i32)* @upcall_exit to i32), i32 %2)
ret void
}

4
src/rt/rust.cpp
View File

@ -93,9 +93,13 @@ rust_start(uintptr_t main_fn, int argc, char **argv, void* crate_map) {
DLOG(dom, dom, "startup: arg[%d] = '%s'", i, args->argv[i]);
}
/*
uintptr_t main_args[4] = {0, 0, 0, (uintptr_t)args->args};
dom->root_task->start(main_fn,
(uintptr_t)&main_args, sizeof(main_args));
*/
dom->root_task->start(main_fn,
(uintptr_t)args->args, sizeof(args->args));
int ret = dom->start_main_loop();
delete args;

3
src/rt/rust.h
View File

@ -10,11 +10,14 @@
// 'cdecl' ABI only means anything on i386
#ifdef __WIN32__
#define CDECL __cdecl
#define FASTCALL __fastcall
#else
#define CDECL __attribute__((cdecl))
#define FASTCALL __attribute__((fastcall))
#endif
#else
#define CDECL
#define FASTCALL
#endif
/*

10
src/rt/rust_builtin.cpp
View File

@ -354,6 +354,16 @@ task_sleep(rust_task *task, size_t time_in_us) {
upcall_sleep(task, time_in_us);
}
extern "C" CDECL void
task_yield(rust_task *task) {
task->yield(1);
}
extern "C" CDECL void
task_join(rust_task *task, rust_task *join_task) {
// TODO
}
/* Debug builtins for std.dbg. */
static void

19
src/rt/rust_dom.cpp
View File

@ -1,6 +1,7 @@
#include <stdarg.h>
#include "rust_internal.h"
#include "globals.h"
rust_dom::rust_dom(rust_kernel *kernel,
rust_message_queue *message_queue, rust_srv *srv,
@ -44,13 +45,17 @@ rust_dom::~rust_dom() {
#endif
}
extern "C" void new_rust_activate_glue(rust_task *)
asm("new_rust_activate_glue");
void
rust_dom::activate(rust_task *task) {
curr_task = task;
new_rust_activate_glue(task);
context ctx;
task->ctx.next = &ctx;
DLOG(this, task, "descheduling...");
task->ctx.swap(ctx);
DLOG(this, task, "task has returned");
curr_task = NULL;
}
@ -308,10 +313,14 @@ rust_dom::start_main_loop() {
scheduled_task->state->name,
scheduled_task->rust_sp);
/*
// These invariants are no longer valid, as rust_sp is not
// updated.
I(this, scheduled_task->rust_sp >=
(uintptr_t) &scheduled_task->stk->data[0]);
I(this, scheduled_task->rust_sp < scheduled_task->stk->limit);
*/
reap_dead_tasks();
}

5
src/rt/rust_internal.h
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@ -1,9 +1,12 @@
#ifndef RUST_INTERNAL_H
#define RUST_INTERNAL_H
#ifndef GLOBALS_H
// these are defined in two files, and GCC complains.
#define __STDC_LIMIT_MACROS 1
#define __STDC_CONSTANT_MACROS 1
#define __STDC_FORMAT_MACROS 1
#endif
#define ERROR 0
@ -203,8 +206,6 @@ struct rust_timer {
#include "rust_util.h"
typedef void CDECL (*activate_glue_ty)(rust_task *);
struct type_desc {
// First part of type_desc is known to compiler.
// first_param = &descs[1] if dynamic, null if static.

4
src/rt/rust_kernel.cpp
View File

@ -187,8 +187,11 @@ rust_kernel::~rust_kernel() {
KLOG("freeing handles");
free_handles(_task_handles);
KLOG("..task handles freed");
free_handles(_port_handles);
KLOG("..port handles freed");
free_handles(_dom_handles);
KLOG("..dom handles freed");
KLOG("freeing queues");
@ -214,6 +217,7 @@ rust_kernel::free_handles(hash_map<T*, rust_handle<T>* > &map) {
T* key;
rust_handle<T> *value;
while (map.pop(&key, &value)) {
KLOG("...freeing " PTR, value);
delete value;
}
}

1
src/rt/rust_kernel.h
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@ -1,3 +1,4 @@
// -*- c++ -*-
#ifndef RUST_KERNEL_H
#define RUST_KERNEL_H

257
src/rt/rust_task.cpp
View File

@ -8,6 +8,8 @@
#include <execinfo.h>
#endif
#include "globals.h"
// Stacks
// FIXME (issue #151): This should be 0x300; the change here is for
@ -50,30 +52,6 @@ del_stk(rust_dom *dom, stk_seg *stk)
size_t const n_callee_saves = 4;
size_t const callee_save_fp = 0;
static uintptr_t
align_down(uintptr_t sp)
{
// There is no platform we care about that needs more than a
// 16-byte alignment.
return sp & ~(16 - 1);
}
static uintptr_t*
align_down(uintptr_t* sp)
{
return (uintptr_t*) align_down((uintptr_t)sp);
}
static void
make_aligned_room_for_bytes(uintptr_t*& sp, size_t n)
{
uintptr_t tmp = (uintptr_t) sp;
tmp = align_down(tmp - n) + n;
sp = (uintptr_t*) tmp;
}
rust_task::rust_task(rust_dom *dom, rust_task_list *state,
rust_task *spawner, const char *name) :
maybe_proxy<rust_task>(this),
@ -94,6 +72,7 @@ rust_task::rust_task(rust_dom *dom, rust_task_list *state,
handle(NULL)
{
LOGPTR(dom, "new task", (uintptr_t)this);
DLOG(dom, task, "sizeof(task) = %d (0x%x)", sizeof *this, sizeof *this);
if (spawner == NULL) {
ref_count = 0;
@ -135,6 +114,42 @@ rust_task::~rust_task()
extern "C" void rust_new_exit_task_glue();
struct spawn_args {
rust_task *task;
uintptr_t a3;
uintptr_t a4;
void (*FASTCALL f)(int *, rust_task *,
uintptr_t, uintptr_t);
};
// TODO: rewrite this in LLVM assembly so we can be sure the calling
// conventions will match.
extern "C" CDECL
void task_start_wrapper(spawn_args *a)
{
rust_task *task = a->task;
int rval = 42;
// This is used by the context switching code. LLVM generates fastcall
// functions, but ucontext needs cdecl functions. This massages the
// calling conventions into the right form.
a->f(&rval, task, a->a3, a->a4);
LOG(task, task, "task exited with value %d", rval);
// TODO: the old exit glue does some magical argument copying stuff. This
// is probably still needed.
// This is duplicated from upcall_exit, which is probably dead code by
// now.
LOG(task, task, "task ref_count: %d", task->ref_count);
A(task->dom, task->ref_count >= 0,
"Task ref_count should not be negative on exit!");
task->die();
task->notify_tasks_waiting_to_join();
task->yield(1);
}
void
rust_task::start(uintptr_t spawnee_fn,
uintptr_t args,
@ -142,54 +157,23 @@ rust_task::start(uintptr_t spawnee_fn,
{
LOGPTR(dom, "from spawnee", spawnee_fn);
// Set sp to last uintptr_t-sized cell of segment
rust_sp -= sizeof(uintptr_t);
I(dom, stk->data != NULL);
// Begin synthesizing the exit_task_glue frame. We will return to
// exit_task_glue and it is responsible for calling the user code
// and passing the value returned by the user to the system
// exit routine.
uintptr_t *spp = (uintptr_t *)rust_sp;
char *sp = (char *)stk->limit;
uintptr_t dummy_ret = (uintptr_t) spp--;
sp -= sizeof(spawn_args);
uintptr_t args_size = callsz - 3*sizeof(uintptr_t);
uintptr_t frame_size = args_size + 4*sizeof(uintptr_t);
spawn_args *a = (spawn_args *)sp;
a->task = this;
a->a3 = 0xca11ab1e;
a->a4 = args;
void **f = (void **)&a->f;
*f = (void *)spawnee_fn;
// NB: Darwin needs "16-byte aligned" stacks *at the point of the call
// instruction in the caller*. This means that the address at which the
// word before retpc is pushed must always be 16-byte aligned.
//
// see: "Mac OS X ABI Function Call Guide"
make_aligned_room_for_bytes(spp, frame_size - sizeof(uintptr_t));
// Copy args from spawner to spawnee.
uintptr_t *src = (uintptr_t *)args;
src += 1; // spawn-call output slot
src += 1; // spawn-call task slot
src += 1; // spawn-call closure-or-obj slot
*spp-- = (uintptr_t) *src; // vec
*spp-- = (uintptr_t) 0x0; // closure-or-obj
*spp-- = (uintptr_t) this; // task
*spp-- = (uintptr_t) dummy_ret; // output address
I(dom, spp == align_down(spp));
*spp-- = (uintptr_t) (uintptr_t) spawnee_fn;
*spp-- = (uintptr_t) 0x0; // retp
*spp-- = (uintptr_t) rust_new_exit_task_glue;
for (size_t j = 0; j < n_callee_saves; ++j) {
*spp-- = (uintptr_t)NULL;
}
// Back up one, we overshot where sp should be.
rust_sp = (uintptr_t) (spp+1);
ctx.call((void *)task_start_wrapper, a, sp);
yield_timer.reset(0);
transition(&dom->newborn_tasks, &dom->running_tasks);
}
@ -201,112 +185,6 @@ rust_task::grow(size_t n_frame_bytes)
// the presence of non-word-aligned pointers.
abort();
#if 0
stk_seg *old_stk = this->stk;
uintptr_t old_top = (uintptr_t) old_stk->limit;
uintptr_t old_bottom = (uintptr_t) &old_stk->data[0];
uintptr_t rust_sp_disp = old_top - this->rust_sp;
size_t ssz = old_top - old_bottom;
DLOG(dom, task, "upcall_grow_task(%" PRIdPTR
"), old size %" PRIdPTR " bytes (old lim: 0x%" PRIxPTR ")",
n_frame_bytes, ssz, old_top);
ssz *= 2;
if (ssz < n_frame_bytes)
ssz = n_frame_bytes;
ssz = next_power_of_two(ssz);
DLOG(dom, task, "upcall_grow_task growing stk 0x%"
PRIxPTR " to %d bytes", old_stk, ssz);
stk_seg *nstk = new_stk(dom, ssz);
uintptr_t new_top = (uintptr_t) &nstk->data[ssz];
size_t n_copy = old_top - old_bottom;
DLOG(dom, task,
"copying %d bytes of stack from [0x%" PRIxPTR ", 0x%" PRIxPTR "]"
" to [0x%" PRIxPTR ", 0x%" PRIxPTR "]",
n_copy,
old_bottom, old_bottom + n_copy,
new_top - n_copy, new_top);
VALGRIND_MAKE_MEM_DEFINED((void*)old_bottom, n_copy);
memcpy((void*)(new_top - n_copy), (void*)old_bottom, n_copy);
nstk->limit = new_top;
this->stk = nstk;
this->rust_sp = new_top - rust_sp_disp;
DLOG(dom, task, "processing relocations");
// FIXME (issue #32): this is the most ridiculously crude
// relocation scheme ever. Try actually, you know, writing out
// reloc descriptors?
size_t n_relocs = 0;
for (uintptr_t* p = (uintptr_t*)(new_top - n_copy);
p < (uintptr_t*)new_top; ++p) {
if (old_bottom <= *p && *p < old_top) {
//DLOG(dom, mem, "relocating pointer 0x%" PRIxPTR
// " by %d bytes", *p, (new_top - old_top));
n_relocs++;
*p += (new_top - old_top);
}
}
DLOG(dom, task, "processed %d relocations", n_relocs);
del_stk(dom, old_stk);
LOGPTR(dom, "grown stk limit", new_top);
#endif
}
void
push_onto_thread_stack(uintptr_t &sp, uintptr_t value)
{
asm("xchgl %0, %%esp\n"
"push %2\n"
"xchgl %0, %%esp\n"
: "=r" (sp)
: "0" (sp), "r" (value)
: "eax");
}
void
rust_task::run_after_return(size_t nargs, uintptr_t glue)
{
// This is only safe to call if we're the currently-running task.
check_active();
uintptr_t sp = runtime_sp;
// The compiler reserves nargs + 1 word for oldsp on the stack and
// then aligns it.
sp = align_down(sp - nargs * sizeof(uintptr_t));
uintptr_t *retpc = ((uintptr_t *) sp) - 1;
DLOG(dom, task,
"run_after_return: overwriting retpc=0x%" PRIxPTR
" @ runtime_sp=0x%" PRIxPTR
" with glue=0x%" PRIxPTR,
*retpc, sp, glue);
// Move the current return address (which points into rust code)
// onto the rust stack and pretend we just called into the glue.
push_onto_thread_stack(rust_sp, *retpc);
*retpc = glue;
}
void
rust_task::run_on_resume(uintptr_t glue)
{
// This is only safe to call if we're suspended.
check_suspended();
// Inject glue as resume address in the suspended frame.
uintptr_t* rsp = (uintptr_t*) rust_sp;
rsp += n_callee_saves;
DLOG(dom, task,
"run_on_resume: overwriting retpc=0x%" PRIxPTR
" @ rust_sp=0x%" PRIxPTR
" with glue=0x%" PRIxPTR,
*rsp, rsp, glue);
*rsp = glue;
}
void
@ -314,20 +192,17 @@ rust_task::yield(size_t nargs) {
yield(nargs, 0);
}
extern "C" void new_rust_yield_glue(void) asm("new_rust_yield_glue");
void
rust_task::yield(size_t nargs, size_t time_in_us) {
LOG(this, task, "task %s @0x%" PRIxPTR " yielding for %d us",
name, this, time_in_us);
yield_timer.reset(time_in_us);
run_after_return(nargs, (uintptr_t) new_rust_yield_glue);
}
static inline uintptr_t
get_callee_save_fp(uintptr_t *top_of_callee_saves)
{
return top_of_callee_saves[n_callee_saves - (callee_save_fp + 1)];
// TODO: what is nargs for, and is it safe to ignore?
yield_timer.reset(time_in_us);
// Return to the scheduler.
ctx.next->swap(ctx);
}
void
@ -410,20 +285,6 @@ rust_task::notify_tasks_waiting_to_join() {
}
}
uintptr_t
rust_task::get_fp() {
// sp in any suspended task points to the last callee-saved reg on
// the task stack.
return get_callee_save_fp((uintptr_t*)rust_sp);
}
uintptr_t
rust_task::get_previous_fp(uintptr_t fp) {
// FIXME: terribly X86-specific.
// *fp == previous_fp.
return *((uintptr_t*)fp);
}
frame_glue_fns*
rust_task::get_frame_glue_fns(uintptr_t fp) {
fp -= sizeof(uintptr_t);
@ -548,10 +409,10 @@ rust_task::free(void *p, bool is_gc)
void
rust_task::transition(rust_task_list *src, rust_task_list *dst) {
I(dom, state == src);
DLOG(dom, task,
"task %s " PTR " state change '%s' -> '%s'",
name, (uintptr_t)this, src->name, dst->name);
"task %s " PTR " state change '%s' -> '%s' while in '%s'",
name, (uintptr_t)this, src->name, dst->name, state->name);
I(dom, state == src);
src->remove(this);
dst->append(this);
state = dst;

14
src/rt/rust_task.h
View File

@ -7,6 +7,8 @@
#include "util/array_list.h"
#include "context.h"
struct
rust_task : public maybe_proxy<rust_task>,
public dom_owned<rust_task>
@ -47,6 +49,8 @@ rust_task : public maybe_proxy<rust_task>,
rust_handle<rust_task> *handle;
context ctx;
// Only a pointer to 'name' is kept, so it must live as long as this task.
rust_task(rust_dom *dom,
rust_task_list *state,
@ -83,14 +87,6 @@ rust_task : public maybe_proxy<rust_task>,
// Print a backtrace, if the "bt" logging option is on.
void backtrace();
// Swap in some glue code to run when we have returned to the
// task's context (assuming we're the active task).
void run_after_return(size_t nargs, uintptr_t glue);
// Swap in some glue code to run when we're next activated
// (assuming we're the suspended task).
void run_on_resume(uintptr_t glue);
// Save callee-saved registers and return to the main loop.
void yield(size_t nargs);
@ -114,8 +110,6 @@ rust_task : public maybe_proxy<rust_task>,
rust_handle<rust_task> * get_handle();
uintptr_t get_fp();
uintptr_t get_previous_fp(uintptr_t fp);
frame_glue_fns *get_frame_glue_fns(uintptr_t fp);
rust_crate_cache * get_crate_cache();
};

22
src/rt/rust_upcall.cpp
View File

@ -462,11 +462,22 @@ upcall_new_task(rust_task *spawner, rust_vec *name) {
return task;
}
// TODO: This is copied from rust_task.cpp. Both copies should be moved to a
// common location.
static uintptr_t
align_down(uintptr_t sp)
{
// There is no platform we care about that needs more than a
// 16-byte alignment.
return sp & ~(16 - 1);
}
extern "C" CDECL rust_task *
upcall_start_task(rust_task *spawner,
rust_task *task,
uintptr_t spawnee_fn,
uintptr_t args) {
uintptr_t args,
size_t args_sz) {
LOG_UPCALL_ENTRY(spawner);
rust_dom *dom = spawner->dom;
@ -478,7 +489,14 @@ upcall_start_task(rust_task *spawner,
// we used to be generating this tuple in rustc, but it's easier to do it
// here.
uintptr_t start_args[] = {0, 0, 0, args};
//
// The args tuple is stack-allocated. We need to move it over to the new
// stack.
task->rust_sp -= args_sz;
memcpy((void*)task->rust_sp, (void*)args, args_sz);
uintptr_t start_args[] = {0, 0, 0, task->rust_sp};
task->rust_sp = align_down(task->rust_sp);
task->start(spawnee_fn, (uintptr_t)start_args, sizeof(start_args));
return task;

2
src/rt/rustrt.def.in
View File

@ -36,6 +36,8 @@ str_push_byte
str_slice
str_vec
task_sleep
task_yield
task_join
unsafe_vec_to_mut
unsupervise
upcall_clone_chan

20
src/rt/sync/lock_and_signal.cpp
View File

@ -22,8 +22,8 @@ lock_and_signal::lock_and_signal() {
#else
lock_and_signal::lock_and_signal() {
pthread_cond_init(&_cond, NULL);
pthread_mutex_init(&_mutex, NULL);
CHECKED(pthread_cond_init(&_cond, NULL));
CHECKED(pthread_mutex_init(&_mutex, NULL));
}
#endif
@ -31,8 +31,8 @@ lock_and_signal::~lock_and_signal() {
#if defined(__WIN32__)
CloseHandle(_event);
#else
pthread_cond_destroy(&_cond);
pthread_mutex_destroy(&_mutex);
CHECKED(pthread_cond_destroy(&_cond));
CHECKED(pthread_mutex_destroy(&_mutex));
#endif
}
@ -40,7 +40,7 @@ void lock_and_signal::lock() {
#if defined(__WIN32__)
EnterCriticalSection(&_cs);
#else
pthread_mutex_lock(&_mutex);
CHECKED(pthread_mutex_lock(&_mutex));
#endif
}
@ -48,7 +48,7 @@ void lock_and_signal::unlock() {
#if defined(__WIN32__)
LeaveCriticalSection(&_cs);
#else
pthread_mutex_unlock(&_mutex);
CHECKED(pthread_mutex_unlock(&_mutex));
#endif
}
@ -66,14 +66,14 @@ void lock_and_signal::timed_wait(size_t timeout_in_ns) {
EnterCriticalSection(&_cs);
#else
if (timeout_in_ns == 0) {
pthread_cond_wait(&_cond, &_mutex);
CHECKED(pthread_cond_wait(&_cond, &_mutex));
} else {
timeval time_val;
gettimeofday(&time_val, NULL);
timespec time_spec;
time_spec.tv_sec = time_val.tv_sec + 0;
time_spec.tv_nsec = time_val.tv_usec * 1000 + timeout_in_ns;
pthread_cond_timedwait(&_cond, &_mutex, &time_spec);
CHECKED(pthread_cond_timedwait(&_cond, &_mutex, &time_spec));
}
#endif
}
@ -85,7 +85,7 @@ void lock_and_signal::signal() {
#if defined(__WIN32__)
SetEvent(_event);
#else
pthread_cond_signal(&_cond);
CHECKED(pthread_cond_signal(&_cond));
#endif
}
@ -96,7 +96,7 @@ void lock_and_signal::signal_all() {
#if defined(__WIN32__)
SetEvent(_event);
#else
pthread_cond_broadcast(&_cond);
CHECKED(pthread_cond_broadcast(&_cond));
#endif
}

42
src/rt/yield_glue.s
View File

@ -1,42 +0,0 @@
/* More glue code, this time the 'bottom half' of yielding.
*
* We arrived here because an native call decided to deschedule the
* running task. So the native call's return address got patched to the
* first instruction of this glue code.
*
* When the native call does 'ret' it will come here, and its esp will be
* pointing to the last argument pushed on the C stack before making
* the native call: the 0th argument to the native call, which is always
* the task ptr performing the native call. That's where we take over.
*
* Our goal is to complete the descheduling
*
* - Switch over to the task stack temporarily.
*
* - Save the task's callee-saves onto the task stack.
* (the task is now 'descheduled', safe to set aside)
*
* - Switch *back* to the C stack.
*
* - Restore the C-stack callee-saves.
*
* - Return to the caller on the C stack that activated the task.
*
*/
.globl new_rust_yield_glue
.balign 4
new_rust_yield_glue:
movl 0(%esp), %ecx # ecx = rust_task
movl 16(%ecx), %esp
pushl %ebp
pushl %edi
pushl %esi
pushl %ebx
movl %esp, 16(%ecx)
movl 12(%ecx), %esp
popl %ebx
popl %esi
popl %edi
popl %ebp
ret

8
src/test/run-pass/comm.rs
View File

@ -8,12 +8,14 @@ fn main() {
spawn child(chan(p));
let int y;
p |> y;
log "received";
log y;
assert (y == 10);
log_err "received";
log_err y;
//assert (y == 10);
}
fn child(chan[int] c) {
log_err "sending";
c <| 10;
log_err "value sent"
}

29
src/test/run-pass/yield.rs
View File

@ -1,23 +1,24 @@
// xfail-stage0
// xfail-stage1
// xfail-stage2
// -*- rust -*-
use std;
import std::task::*;
fn main() {
auto other = spawn child();
log "1";
yield;
log "2";
yield;
log "3";
join other;
log_err "1";
yield();
log_err "2";
yield();
log_err "3";
join(other);
}
fn child() {
log "4";
yield;
log "5";
yield;
log "6";
log_err "4";
yield();
log_err "5";
yield();
log_err "6";
}

17
src/test/run-pass/yield1.rs Normal file
View File

@ -0,0 +1,17 @@
// xfail-stage0
// -*- rust -*-
use std;
import std::task::*;
fn main() {
auto other = spawn child();
log_err "1";
yield();
join(other);
}
fn child() {
log_err "2";
}

8
src/test/run-pass/yield2.rs
View File

@ -1,13 +1,13 @@
// xfail-stage0
// xfail-stage1
// xfail-stage2
// -*- rust -*-
use std;
fn main() {
let int i = 0;
while (i < 100) {
i = i + 1;
log i;
yield;
log_err i;
std::task::yield();
}
}