Array c_WaitableWaitHandle::t_getdependencystack() {
Array result = Array::Create();
if (isFinished()) return result;
hphp_hash_set<int64_t> visited;
auto wait_handle = this;
auto session = AsioSession::Get();
while (wait_handle != nullptr) {
result.append(wait_handle);
visited.insert(wait_handle->t_getid());
auto context_idx = wait_handle->getContextIdx();
// 1. find parent in the same context
auto p = wait_handle->getParentChain().firstInContext(context_idx);
if (p && visited.find(p->t_getid()) == visited.end()) {
wait_handle = p;
continue;
}
// 2. cross the context boundary
auto context = session->getContext(context_idx);
if (!context) {
break;
}
wait_handle = c_ResumableWaitHandle::getRunning(context->getSavedFP());
auto target_context_idx = wait_handle ? wait_handle->getContextIdx() : 0;
while (context_idx > target_context_idx) {
--context_idx;
result.append(null_object);
}
}
return result;
}
Array c_WaitableWaitHandle::t_getdependencystack() {
Array result = Array::Create();
if (isFinished()) return result;
hphp_hash_set<int64_t> visited;
auto wait_handle = this;
while (wait_handle != nullptr) {
result.append(wait_handle);
visited.insert(wait_handle->t_getid());
auto context_idx = wait_handle->getContextIdx();
// 1. find parent in the same context
auto p = wait_handle->getFirstParent();
while (p) {
if ((p->getContextIdx() == context_idx) &&
visited.find(p->t_getid()) == visited.end()) {
wait_handle = p;
break;
}
p = p->getNextParent();
}
if (p) continue;
// 2. cross the context boundary
result.append(null_object);
wait_handle = (context_idx > 1)
? AsioSession::Get()->getContext(context_idx - 1)->getCurrent()
: nullptr;
}
return result;
}
// Form a trace of the async stack starting with the currently running
// generator, if any. For now we just toss in the function name and
// id, as well as the pseudo-frames for context breaks at explicit
// joins. Later we'll add more, like file and line, hopefully function
// args, wait handle status, etc.
static Array createAsyncStacktrace() {
Array trace;
auto currentWaitHandle = HHVM_FN(asio_get_running)();
if (currentWaitHandle.isNull()) return trace;
Array depStack =
objToWaitableWaitHandle(currentWaitHandle)->t_getdependencystack();
for (ArrayIter iter(depStack); iter; ++iter) {
if (iter.secondRef().isNull()) {
trace.append(Array(staticEmptyArray()));
} else {
auto wh = objToWaitableWaitHandle(iter.secondRef().toObject());
auto parents = wh->t_getparents();
Array ancestors;
for (ArrayIter piter(parents); piter; ++piter) {
// Note: the parent list contains no nulls.
auto parent = objToWaitableWaitHandle(piter.secondRef().toObject());
ancestors.append(parent->t_getname());
}
Array frameData;
frameData.set(s_function, wh->t_getname(), true);
frameData.set(s_id, wh->t_getid(), true);
frameData.set(s_ancestors, ancestors, true);
// Async function wait handles may have a source location to add.
if (wh->getKind() == c_WaitHandle::Kind::AsyncFunction) {
auto afwh = static_cast<c_AsyncFunctionWaitHandle*>(wh);
addAsyncFunctionLocation(frameData, *afwh);
}
trace.append(frameData);
}
}
return trace;
}
// always throws
void c_BlockableWaitHandle::reportCycle(c_WaitableWaitHandle* start) {
assert(getState() == STATE_BLOCKED);
assert(getChild() == start);
smart::vector<std::string> exception_msg_items;
exception_msg_items.push_back("Encountered dependency cycle.\n");
exception_msg_items.push_back("Existing stack:\n");
assert(dynamic_cast<c_BlockableWaitHandle*>(start));
auto current = static_cast<c_BlockableWaitHandle*>(start);
assert(current->getState() == STATE_BLOCKED);
do {
exception_msg_items.push_back(folly::stringPrintf(
" %s (%" PRId64 ")\n", current->getName()->data(), current->t_getid()));
auto next = current->getChild();
assert(dynamic_cast<c_BlockableWaitHandle*>(next));
current = static_cast<c_BlockableWaitHandle*>(next);
assert(current->getState() == STATE_BLOCKED);
} while (current != start);
exception_msg_items.push_back("Trying to introduce dependency on:\n");
exception_msg_items.push_back(folly::stringPrintf(
" %s (%" PRId64 ") (dupe)\n", start->getName()->data(), start->t_getid()));
Object e(SystemLib::AllocInvalidOperationExceptionObject(
folly::join("", exception_msg_items)));
throw e;
}
ObjectData*
c_BlockableWaitHandle::createCycleException(c_WaitableWaitHandle* child) const {
assert(isDescendantOf(child));
smart::vector<std::string> exception_msg_items;
exception_msg_items.push_back("Encountered dependency cycle.\n");
exception_msg_items.push_back("Existing stack:\n");
exception_msg_items.push_back(folly::stringPrintf(
" %s (%" PRId64 ")\n", child->getName().data(), child->t_getid()));
assert(child->instanceof(c_BlockableWaitHandle::classof()));
auto current = static_cast<c_BlockableWaitHandle*>(child);
while (current != this) {
assert(current->getState() == STATE_BLOCKED);
assert(current->getChild()->instanceof(c_BlockableWaitHandle::classof()));
current = static_cast<c_BlockableWaitHandle*>(current->getChild());
exception_msg_items.push_back(folly::stringPrintf(
" %s (%" PRId64 ")\n", current->getName().data(), current->t_getid()));
}
exception_msg_items.push_back("Trying to introduce dependency on:\n");
exception_msg_items.push_back(folly::stringPrintf(
" %s (%" PRId64 ") (dupe)\n", child->getName().data(), child->t_getid()));
return SystemLib::AllocInvalidOperationExceptionObject(
folly::join("", exception_msg_items));
}
// Form a trace of the async stack starting with the currently running
// generator, if any. For now we just toss in the function name and
// id, as well as the pseudo-frames for context breaks at explicit
// joins. Later we'll add more, like file and line, hopefully function
// args, wait handle status, etc.
Array createAsyncStacktrace() {
Array trace;
auto currentWaitHandle = f_asio_get_running();
if (currentWaitHandle.isNull()) return trace;
Array depStack =
objToWaitableWaitHandle(currentWaitHandle)->t_getdependencystack();
for (ArrayIter iter(depStack); iter; ++iter) {
if (iter.secondRef().isNull()) {
trace.append(ArrayInit(0).toVariant());
} else {
auto wh = objToWaitableWaitHandle(iter.secondRef().toObject());
auto parents = wh->t_getparents();
Array ancestors;
for (ArrayIter piter(parents); piter; ++piter) {
// Note: the parent list contains no nulls.
auto parent = objToWaitableWaitHandle(piter.secondRef().toObject());
ancestors.append(parent->t_getname());
}
Array frameData;
frameData.set(s_function, wh->t_getname(), true);
frameData.set(s_id, wh->t_getid(), true);
frameData.set(s_ancestors, ancestors, true);
// Continuation wait handles may have a source location to add.
auto contWh = dynamic_cast<c_AsyncFunctionWaitHandle*>(wh);
if (contWh != nullptr) addContinuationLocation(frameData, *contWh);
trace.append(frameData);
}
}
return trace;
}
