In computing, a task is a unit of execution or a unit of work. The term is ambiguous; precise alternative terms include process, light-weight process, thread (for execution), step, request, or query (for work). In the adjacent diagram, there are queues of incoming work to do and outgoing completed work, and a thread pool of threads to perform this work. Either the work units themselves or the threads that perform the work can be referred to as "tasks", and these can be referred to respectively as requests/responses/threads, incoming tasks/completed tasks/threads (as illustrated), or requests/responses/tasks.

module_config {
    module_library : "/apollo/bazel-bin/modules/canbus/libcanbus.so"
    timer_components {
        class_name : "CanbusComponent"
        config {
            name: "canbus"
            config_file_path:  "/apollo/modules/canbus/conf/canbus_conf.pb.txt"
            flag_file_path:  "/apollo/modules/canbus/conf/canbus.conf"
            interval: 10
        }
    }
}

module_config {
    module_library : "/apollo/bazel-bin/modules/planning/libplanning_component.so"
    components {
        class_name : "PlanningComponent"
        config {
        name: "planning"
        flag_file_path:  "/apollo/modules/planning/conf/planning.conf"
        readers: [
            {
            channel: "/apollo/prediction"
            },
            {
            channel: "/apollo/canbus/chassis"
            qos_profile: {
                depth : 15
            }
            pending_queue_size: 50
            },
            {
            channel: "/apollo/localization/pose"
            qos_profile: {
                depth : 15
            }
            pending_queue_size: 50
            }
        ]
        }
    }
}

SchedulerClassic
Choreography Classic就是根據用家給的scheduler conf去給每個task priority，然後就按conf中預先設定的priority去做。還支持把Processor做分組，某不同range的Processor負責不同的種類的任務。
SchedulerClassic中的ClassicContext是用static變量去放CRoutine的，CRoutine不能保證自己被該組中的那一個Processor執行。而每個ClassicContext都有一個group_name_，那Processor在拿Task時只會拿到該group的Task。

SchedulerChoreography
SchedulerChoreography跟SchedulerClassic沒有差很大，它是在支持SchedulerClassic的前題下（但不支持Processor分組)，把一部份的processor留出來，容許你指定每個task用當中那一個processor。所以被特別留出來的processor，各有一個自己的context，不跟其他processor共用，確保該processor只會處理指定的Task

scheduler_conf {
    policy: "classic"
    classic_conf {
        groups: [
        {
            name: "control"
            processor_num: 8
            affinity: "range"
            cpuset: "8-15"
            processor_policy: "SCHED_OTHER"
            processor_prio: 0
            tasks: [
            {
                name: "control_/apollo/planning"
                prio: 10
            },
            {
                name: "canbus_/apollo/control"
                prio: 11
            }
            ]
        }
        ]
    }
}

scheduler_conf {
    policy: "choreography"

    choreography_conf {
        choreography_processor_num: 2
        choreography_affinity: "range"
        choreography_cpuset: "8-12"
        choreography_processor_policy: "SCHED_FIFO"

        pool_processor_num: 2
        pool_affinity: "range"
        pool_cpuset: "12-15"
        pool_processor_policy: "SCHED_OTHER"

        tasks: [
        {
            name: "control_/apollo/planning"
            processor: 0
        },
        {
            name: "canbus_/apollo/control"
            processor: 0
            prio: 2
        }

        {
            name: "guardian"
            processor: 1
        },
        ]
    }
}