void become_dependent(THREAD, utilities::thread::Condition* cond = NULL) {
switch(state->run_state()) {
case ManagedThread::eAlone:
// Running alone, ignore.
return;
case ManagedThread::eRunning:
// Ignore this, a running thread is already dependent.
return;
case ManagedThread::eSuspended:
// Again, bad, don't allow this.
rubinius::bug("Trying to make a suspended thread dependent");
break;
case ManagedThread::eIndependent:
// If the GC is running, wait here...
if(should_stop_) {
utilities::thread::Mutex::LockGuard guard(mutex_);
state->run_state_ = ManagedThread::eSuspended;
if(cond) cond->broadcast();
// We need to grab the mutex because we might want
// to wait here.
while(should_stop_) {
waiting_to_run_.wait(mutex_);
}
}
// Ok, we're running again.
state->run_state_ = ManagedThread::eRunning;
atomic::fetch_and_add(&pending_threads_, 1);
}
}
void wait_to_run(THREAD) {
if(cDebugThreading) {
std::cerr << "[" << VM::current() << " WORLD stopping, waiting to be restarted]\n";
}
if(state->run_state_ != ManagedThread::eRunning) {
rubinius::bug("Suspending a non running thread!");
}
state->run_state_ = ManagedThread::eSuspended;
atomic::fetch_and_sub(&pending_threads_, 1);
utilities::thread::Mutex::LockGuard guard(mutex_);
// Ok, since we have just locked that implies a barrier
// so we don't have to add an explicit barrier here.
while(should_stop_) {
waiting_to_run_.wait(mutex_);
}
atomic::fetch_and_add(&pending_threads_, 1);
state->run_state_ = ManagedThread::eRunning;
if(cDebugThreading) {
std::cerr << "[" << VM::current() << " WORLD restarted]\n";
}
}
void pause() {
utilities::thread::Mutex::LockGuard guard(mutex_);
// it's idle, ie paused.
if(state == cIdle || state == cPaused) return;
pause_ = true;
while(!paused_ && (ls_->run_state() == ManagedThread::eRunning ||
ls_->run_state() == ManagedThread::eIndependent)) {
pause_condition_.wait(mutex_);
}
}
void become_dependent(THREAD, utilities::thread::Condition* cond = NULL) {
switch(state->run_state()) {
case ManagedThread::eAlone:
// Running alone, ignore.
return;
case ManagedThread::eRunning:
// Ignore this, a running thread is already dependent.
return;
case ManagedThread::eSuspended:
// Again, bad, don't allow this.
rubinius::bug("Trying to make a suspended thread dependent");
break;
case ManagedThread::eIndependent:
for(;;) {
// If the GC is running, wait here...
if(should_stop_) {
utilities::thread::Mutex::LockGuard guard(mutex_);
state->run_state_ = ManagedThread::eSuspended;
if(cond) cond->broadcast();
// We need to grab the mutex because we might want
// to wait here.
while(should_stop_) {
waiting_to_run_.wait(mutex_);
}
}
// Ok, we're running again.
state->run_state_ = ManagedThread::eRunning;
atomic::fetch_and_add(&pending_threads_, 1);
// After decreasing the thread count, we have to check whether
// we might have to stop. This is basically because
// there is a race condition here that should_stop isn't true
// yet the first time before incrementing. However, another thread
// waiting to GC could have set should_stop and not seen the
// increment of this thread yet, thinking it's safe to GC.
//
if(!atomic::read(&should_stop_)) return;
// If we do have to stop, subtract one from the thread count
// and retry again. This will make the thread go into the wait.
atomic::fetch_and_sub(&pending_threads_, 1);
}
}
}
void stop_threads_externally() {
while(!atomic::compare_and_swap(&should_stop_, 0, 1)) {
if(cDebugThreading) {
std::cerr << "[WORLD waiting to stopping all threads (as external event)]\n";
}
// Wait around on the run condition variable until whoever is currently
// working independently is done and sets should_stop_ to false.
utilities::thread::Mutex::LockGuard guard(mutex_);
while(should_stop_) {
waiting_to_run_.wait(mutex_);
}
// We will now redo the loop to check if we can stop properly this time
}
if(cDebugThreading) {
std::cerr << "[WORLD stopping all threads (as external event)]\n";
}
*check_global_interrupts_ = true;
// We need a write barrier so we're sure we're seeing an up to
// date version of pending_threads_ in each loop.
while(atomic::read(&pending_threads_) > 0) {
if(cDebugThreading) {
std::cerr << "[" << VM::current() << " WORLD waiting on condvar: "
<< pending_threads_ << "]\n";
}
// We yield here so other threads are scheduled and can be run.
// We've benchmarked this and this turned out to cause the least
// cpu burn compared to not doing anything at all here or sleeping
// for 1 nanosecond with {0, 1}.
atomic::pause();
}
if(cDebugThreading) {
std::cerr << "[" << VM::current() << " WORLD o/~ I think we're alone now.. o/~]\n";
}
}
virtual void perform() {
const char* thread_name = "rbx.jit";
ManagedThread::set_current(ls_, thread_name);
ls_->set_run_state(ManagedThread::eIndependent);
RUBINIUS_THREAD_START(thread_name, ls_->thread_id(), 1);
#ifndef RBX_WINDOWS
sigset_t set;
sigfillset(&set);
pthread_sigmask(SIG_SETMASK, &set, NULL);
#endif
for(;;) { // forever
BackgroundCompileRequest* req = 0;
// Lock, wait, get a request, unlock
{
utilities::thread::Mutex::LockGuard guard(mutex_);
if(pause_) {
state = cPaused;
paused_ = true;
pause_condition_.broadcast();
if(stop_) goto halt;
while(pause_) {
condition_.wait(mutex_);
if(stop_) goto halt;
}
state = cUnknown;
paused_ = false;
}
// If we've been asked to stop, do so now.
if(stop_) goto halt;
while(pending_requests_.empty()) {
state = cIdle;
// unlock and wait...
condition_.wait(mutex_);
if(stop_) goto halt;
}
// now locked again, shift a request
req = pending_requests_.front();
state = cRunning;
}
// This isn't ideal, but it's the safest. Keep the GC from
// running while we're building the IR.
ls_->gc_dependent();
Context ctx(ls_);
jit::Compiler jit(&ctx);
// mutex now unlock, allowing others to push more requests
//
current_req_ = req;
current_compiler_ = &jit;
int spec_id = 0;
Class* cls = req->receiver_class();
if(cls && !cls->nil_p()) {
spec_id = cls->class_id();
}
void* func = 0;
{
timer::Running<1000000> timer(ls_->shared().stats.jit_time_spent);
jit.compile(req);
func = jit.generate_function();
}
// We were unable to compile this function, likely
// because it's got something we don't support.
if(!func) {
if(ls_->config().jit_show_compiling) {
CompiledCode* code = req->method();
llvm::outs() << "[[[ JIT error background compiling "
<< ls_->enclosure_name(code) << "#" << ls_->symbol_debug_str(code->name())
<< (req->is_block() ? " (block)" : " (method)")
<< " ]]]\n";
}
// If someone was waiting on this, wake them up.
if(utilities::thread::Condition* cond = req->waiter()) {
cond->signal();
}
current_req_ = 0;
current_compiler_ = 0;
pending_requests_.pop_front();
delete req;
// We don't depend on the GC here, so let it run independent
// of us.
ls_->gc_independent();
continue;
}
if(show_machine_code_) {
jit.show_machine_code();
}
// If the method has had jit'ing request disabled since we started
// JIT'ing it, discard our work.
if(!req->machine_code()->jit_disabled()) {
jit::RuntimeDataHolder* rd = ctx.runtime_data_holder();
atomic::memory_barrier();
ls_->start_method_update();
if(!req->is_block()) {
if(spec_id) {
req->method()->add_specialized(spec_id, reinterpret_cast<executor>(func), rd);
} else {
req->method()->set_unspecialized(reinterpret_cast<executor>(func), rd);
}
} else {
req->method()->set_unspecialized(reinterpret_cast<executor>(func), rd);
}
req->machine_code()->clear_compiling();
// assert(req->method()->jit_data());
ls_->end_method_update();
rd->run_write_barrier(ls_->write_barrier(), req->method());
ls_->shared().stats.jitted_methods++;
if(ls_->config().jit_show_compiling) {
CompiledCode* code = req->method();
llvm::outs() << "[[[ JIT finished background compiling "
<< ls_->enclosure_name(code) << "#" << ls_->symbol_debug_str(code->name())
<< (req->is_block() ? " (block)" : " (method)")
<< " ]]]\n";
}
}
// If someone was waiting on this, wake them up.
if(utilities::thread::Condition* cond = req->waiter()) {
cond->signal();
}
current_req_ = 0;
current_compiler_ = 0;
pending_requests_.pop_front();
delete req;
// We don't depend on the GC here, so let it run independent
// of us.
ls_->gc_independent();
}
halt:
RUBINIUS_THREAD_STOP(thread_name, ls_->thread_id(), 1);
}