brpc/include/bthread/task_group_inl.h
2022-12-14 19:05:52 +08:00

110 lines
4.1 KiB
C++

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
// bthread - A M:N threading library to make applications more concurrent.
// Date: Tue Jul 10 17:40:58 CST 2012
#ifndef BTHREAD_TASK_GROUP_INL_H
#define BTHREAD_TASK_GROUP_INL_H
namespace bthread {
// Utilities to manipulate bthread_t
inline bthread_t make_tid(uint32_t version, butil::ResourceId<TaskMeta> slot) {
return (((bthread_t)version) << 32) | (bthread_t)slot.value;
}
inline butil::ResourceId<TaskMeta> get_slot(bthread_t tid) {
butil::ResourceId<TaskMeta> id = { (tid & 0xFFFFFFFFul) };
return id;
}
inline uint32_t get_version(bthread_t tid) {
return (uint32_t)((tid >> 32) & 0xFFFFFFFFul);
}
inline TaskMeta* TaskGroup::address_meta(bthread_t tid) {
// TaskMeta * m = address_resource<TaskMeta>(get_slot(tid));
// if (m != NULL && m->version == get_version(tid)) {
// return m;
// }
// return NULL;
return address_resource(get_slot(tid));
}
inline void TaskGroup::exchange(TaskGroup** pg, bthread_t next_tid) {
TaskGroup* g = *pg;
if (g->is_current_pthread_task()) {
return g->ready_to_run(next_tid);
}
ReadyToRunArgs args = { g->current_tid(), false };
g->set_remained((g->current_task()->about_to_quit
? ready_to_run_in_worker_ignoresignal
: ready_to_run_in_worker),
&args);
TaskGroup::sched_to(pg, next_tid);
}
inline void TaskGroup::sched_to(TaskGroup** pg, bthread_t next_tid) {
TaskMeta* next_meta = address_meta(next_tid);
if (next_meta->stack == NULL) {
ContextualStack* stk = get_stack(next_meta->stack_type(), task_runner);
if (stk) {
next_meta->set_stack(stk);
} else {
// stack_type is BTHREAD_STACKTYPE_PTHREAD or out of memory,
// In latter case, attr is forced to be BTHREAD_STACKTYPE_PTHREAD.
// This basically means that if we can't allocate stack, run
// the task in pthread directly.
next_meta->attr.stack_type = BTHREAD_STACKTYPE_PTHREAD;
next_meta->set_stack((*pg)->_main_stack);
}
}
// Update now_ns only when wait_task did yield.
sched_to(pg, next_meta);
}
inline void TaskGroup::push_rq(bthread_t tid) {
while (!_rq.push(tid)) {
// Created too many bthreads: a promising approach is to insert the
// task into another TaskGroup, but we don't use it because:
// * There're already many bthreads to run, inserting the bthread
// into other TaskGroup does not help.
// * Insertions into other TaskGroups perform worse when all workers
// are busy at creating bthreads (proved by test_input_messenger in
// brpc)
flush_nosignal_tasks();
LOG_EVERY_SECOND(ERROR) << "_rq is full, capacity=" << _rq.capacity();
// TODO(gejun): May cause deadlock when all workers are spinning here.
// A better solution is to pop and run existing bthreads, however which
// make set_remained()-callbacks do context switches and need extensive
// reviews on related code.
::usleep(1000);
}
}
inline void TaskGroup::flush_nosignal_tasks_remote() {
if (_remote_num_nosignal) {
_remote_rq._mutex.lock();
flush_nosignal_tasks_remote_locked(_remote_rq._mutex);
}
}
} // namespace bthread
#endif // BTHREAD_TASK_GROUP_INL_H