SERVICE_STATUS_PROCESS

SERVICE_STATUS_PROCESS

The SERVICE_STATUS_PROCESS structure contains information about a service. The EnumServicesStatusEx and QueryServiceStatusEx functions use this structure to return information about a service.

typedef struct _SERVICE_STATUS_PROCESS {
DWORD dwServiceType;
DWORD dwCurrentState;
DWORD dwControlsAccepted;
DWORD dwWin32ExitCode;
DWORD dwServiceSpecificExitCode;
DWORD dwCheckPoint;
DWORD dwWaitHint;
DWORD dwProcessId;
DWORD dwServiceFlags; } SERVICE_STATUS_PROCESS,
*LPSERVICE_STATUS_PROCESS;
Members
dwServiceType
Type of service. This member can be one of the following values.
ValueMeaning
SERVICE_FILE_SYSTEM_DRIVER
0x00000002
The service is a file system driver.
SERVICE_KERNEL_DRIVER
0x00000001
The service is a device driver.
SERVICE_WIN32_OWN_PROCESS
0x00000010
The service runs in its own process.
SERVICE_WIN32_SHARE_PROCESS
0x00000020
The service shares a process with other services.

If the service type is either SERVICE_WIN32_OWN_PROCESS or SERVICE_WIN32_SHARE_PROCESS, and the service is running in the context of the LocalSystem account, the following type may also be specified.

ValueMeaning
SERVICE_INTERACTIVE_PROCESSThe service can interact with the desktop.

For more information, see Interactive Services.

dwCurrentState
Current state of the service. This member can be one of the following values.
ValueMeaning
SERVICE_CONTINUE_PENDING
0x00000005
The service continue is pending.
SERVICE_PAUSE_PENDING
0x00000006
The service pause is pending.
SERVICE_PAUSED
0x00000007
The service is paused.
SERVICE_RUNNING
0x00000004
The service is running.
SERVICE_START_PENDING
0x00000002
The service is starting.
SERVICE_STOP_PENDING
0x00000003
The service is stopping.
SERVICE_STOPPED
0x00000001
The service is not running.
dwControlsAccepted
Control codes the service accepts and processes in its handler function (see Handler and HandlerEx). A user interface process can control a service by specifying a control command in the ControlService function. By default, all services accept the SERVICE_CONTROL_INTERROGATE value.

The following are the control codes.

Control codeMeaning
SERVICE_ACCEPT_NETBINDCHANGE
0x00000010
The service is a network component that can accept changes in its binding without being stopped and restarted.

This control code allows the service to receive SERVICE_CONTROL_NETBINDADD, SERVICE_CONTROL_NETBINDREMOVE, SERVICE_CONTROL_NETBINDENABLE, and SERVICE_CONTROL_NETBINDDISABLE notifications.

Windows NT:  This value is not supported.
SERVICE_ACCEPT_PARAMCHANGE
0x00000008
The service can reread its startup parameters without being stopped and restarted.

This control code allows the service to receive SERVICE_CONTROL_PARAMCHANGE notifications.

Windows NT:  This value is not supported.
SERVICE_ACCEPT_PAUSE_CONTINUE
0x00000002
The service can be paused and continued.

This control code allows the service to receive SERVICE_CONTROL_PAUSE and SERVICE_CONTROL_CONTINUE notifications.

SERVICE_ACCEPT_SHUTDOWN
0x00000004
The service is notified when system shutdown occurs.

This control code allows the service to receive SERVICE_CONTROL_SHUTDOWN notifications. Note that ControlService cannot send this notification; only the system can send it.

SERVICE_ACCEPT_STOP
0x00000001
The service can be stopped.

This control code allows the service to receive SERVICE_CONTROL_STOP notifications.

This value can also contain the following extended control codes, which are supported only by HandlerEx. (Note that these control codes cannot be sent by ControlService.)

Control codeMeaning
SERVICE_ACCEPT_HARDWAREPROFILECHANGE
0x00000020
The service is notified when the computer's hardware profile has changed. This enables the system to send SERVICE_CONTROL_HARDWAREPROFILECHANGE notifications to the service.
Windows NT:  This value is not supported.
SERVICE_ACCEPT_POWEREVENT
0x00000040
The service is notified when the computer's power status has changed. This enables the system to send SERVICE_CONTROL_POWEREVENT notifications to the service.
Windows NT:  This value is not supported.
SERVICE_ACCEPT_SESSIONCHANGE
0x00000080
The service is notified when the computer's session status has changed. This enables the system to send SERVICE_CONTROL_SESSIONCHANGE notifications to the service.
Windows 2000/NT:  This value is not supported.
dwWin32ExitCode
Error code that the service uses to report an error that occurs when it is starting or stopping. To return an error code specific to the service, the service must set this value to ERROR_SERVICE_SPECIFIC_ERROR to indicate that the dwServiceSpecificExitCode member contains the error code. The service should set this value to NO_ERROR when it is running and when it terminates normally.
dwServiceSpecificExitCode
Service-specific error code that the service returns when an error occurs while the service is starting or stopping. This value is ignored unless the dwWin32ExitCode member is set to ERROR_SERVICE_SPECIFIC_ERROR.
dwCheckPoint
Check-point value that the service increments periodically to report its progress during a lengthy start, stop, pause, or continue operation. For example, the service should increment this value as it completes each step of its initialization when it is starting up. The user interface program that invoked the operation on the service uses this value to track the progress of the service during a lengthy operation. This value is not valid and should be zero when the service does not have a start, stop, pause, or continue operation pending.
dwWaitHint
Estimated time required for a pending start, stop, pause, or continue operation, in milliseconds. Before the specified amount of time has elapsed, the service should make its next call to the SetServiceStatus function with either an incremented dwCheckPoint value or a change in dwCurrentState. If the amount of time specified by dwWaitHint passes, and dwCheckPoint has not been incremented or dwCurrentState has not changed, the service control manager or service control program can assume that an error has occurred and the service should be stopped.
dwProcessId
Process identifier of the service.
dwServiceFlags
This member can be one of the following values.
ValueMeaning
0The service is running in a process that is not a system process, or it is not running.

If the service is running in a process that is not a system process, dwProcessId is nonzero. If the service is not running, dwProcessId is zero.

SERVICE_RUNS_IN_SYSTEM_PROCESS
0x00000001
The service runs in a system process that must always be running.
Requirements
ClientRequires Windows XP or Windows 2000 Professional.
ServerRequires Windows Server 2003 or Windows 2000 Server.
Header

Declared in Winsvc.h; include Windows.h.

@celery_app.task(ignore_result=True) def run_work_flow(global_data, node, task_id): """工作流任务执行函数""" try: node = init_node_state(node, task_id) node_status = {front_id: node[front_id]['node_state'] for front_id in node} dependencies = {front_id: set(node[front_id]["from"]) for front_id in node} reverse_map = {front_id: node[front_id]["to"] for front_id in node} ready_queue = deque() lock = Lock() with lock: for front_id in node: if not dependencies[front_id] and node_status[front_id] == TaskNodeState.READY.name: ready_queue.append(front_id) def on_completion(c_front_id, future): with lock: try: result = future.result() print(f"任务 {c_front_id} 执行完成,结果: {result}") node[c_front_id]["node_state"] = result node_status[c_front_id] = result update_node_info(task_id, {"node": json.dumps(node), "end_time": int(time.time())}) except Exception as e: print(f"任务 {c_front_id} 执行失败: {str(e)}") print(traceback.format_exc()) for successor in reverse_map[c_front_id]: if node_status[c_front_id] == TaskNodeState.FINISHED: dependencies[successor].discard(c_front_id) print(f"移除任务 {successor} 的依赖: {c_front_id}") if not dependencies[successor] and node_status[successor] == TaskNodeState.READY.name: print(f"任务 {successor} 的所有依赖已完成,加入就绪队列") ready_queue.append(successor) executor.submit(process_queue) def process_queue(): while True: with lock: if not ready_queue: print("就绪队列为空,退出处理") return current_front_id = ready_queue.popleft() if node_status[current_front_id] != TaskNodeState.READY.name: print(f"任务 {current_front_id} 状态不是就绪状态,跳过处理") continue if current_front_id in ["start", "end"]: current_service_name = "complete_start_end_node" else: current_service_name = node[current_front_id]["service_name"] print(f"开始执行任务 {current_front_id},服务名: {current_service_name}") node[current_front_id]["node_state"] = TaskNodeState.RUNNING.name node_status[current_front_id] = TaskNodeState.RUNNING.name update_task(task_id, {"node": json.dumps(node)}) print(f"调用服务函数: {current_service_name} 处理任务 {current_front_id}") future = executor.submit(SERVICE_DICT[current_service_name], node, current_front_id, global_data) future.add_done_callback(lambda f, n=current_front_id: on_completion(n, f)) with concurrent.futures.ThreadPoolExecutor(max_workers=MAX_WORKERS) as executor: executor.submit(process_queue) except Exception as e: print(e) print(traceback.format_exc()) 这个on_completion 中的内容为什么没有执行
最新发布
03-08
<think>好的,我现在需要帮助用户解决关于他们代码中on_completion回调函数没有执行的问题。首先,我需要仔细阅读用户提供的代码,理解整个工作流的执行逻辑。 用户提供的代码是一个使用Celery的任务函数run_work_flow,用于管理工作流节点的执行。其中,on_completion函数作为回调,应该在任务完成后处理结果和更新状态。但用户反映这个回调没有执行。 首先,我需要分析代码的执行流程。任务通过executor.submit提交到线程池,然后future.add_done_callback注册了on_completion。通常,当future完成时,回调会自动触发。如果回调没执行,可能的原因有几个: 1. **任务未正确提交或执行**:可能SERVICE_DICT中的服务函数没有被正确调用,导致future从未完成,因此回调无法触发。需要检查服务函数是否存在,是否抛出异常,或者是否被正确提交。 2. **线程池问题**:ThreadPoolExecutor可能提前关闭,导致回调无法完成。例如,如果主线程退出而任务还在运行,executor可能会被关闭。但用户代码中executor是在with块中创建的,这应该会等待所有任务完成,所以可能不是这个问题。 3. **异常未被捕获**:如果服务函数抛出异常,但future.result()没有正确处理,可能导致回调中的异常被忽略。需要检查是否有未处理的异常,或者回调函数本身出错。 4. **锁竞争或死锁**:代码中使用了Lock(),如果在获取锁时发生阻塞,可能导致回调无法执行。需要确认锁的使用是否正确,是否在某个地方被长时间持有而没有释放。 5. **任务状态不正确**:比如node_status在回调执行前被修改,导致条件判断失败,例如依赖未被正确移除,后续任务无法加入队列。 接下来,我需要逐一排查这些可能性。用户提到on_completion中的打印语句没有执行,说明回调根本没有被调用。可能的原因更倾向于任务没有完成,或者回调没有被正确添加。 查看代码,executor.submit(SERVICE_DICT[current_service_name], ...)返回的future被添加了回调。如果服务函数执行很快,或者抛出异常,future会立即完成,触发回调。如果服务函数本身有阻塞或未执行,future就不会完成。 可能的测试点包括: - 确认SERVICE_DICT[current_service_name]是否正确,服务函数是否存在。 - 检查服务函数是否正常执行,是否有异常被捕获。 - 在future.add_done_callback前后添加日志,确认回调是否被正确注册。 - 检查线程池是否正常关闭,是否有任务被取消。 此外,用户代码中使用的是concurrent.futures的ThreadPoolExecutor,而Celery本身可能涉及异步任务,需要注意线程和任务的管理是否冲突。例如,Celery任务可能在主线程执行,而线程池中的子线程可能因为某些原因提前终止。 另外,代码中的process_queue函数是通过executor.submit(process_queue)提交的,而process_queue内部有一个while循环。如果process_queue因为某些原因(如就绪队列为空)提前退出,可能导致后续任务无法被处理,从而future无法完成,回调无法执行。 还需要检查锁的使用是否正确,特别是在多线程环境下,锁的竞争可能导致某些代码块无法执行。例如,在process_queue中,获取锁后操作就绪队列,但如果在释放锁后,其他线程没有正确唤醒或处理,可能导致任务停滞。 最后,建议用户添加更多的日志输出,特别是在关键点如任务提交、回调注册、服务函数执行前后,以及异常捕获块中,以便更清晰地跟踪执行流程,找出回调未执行的具体原因。</think>这个`on_completion`回调未执行可能有以下几个关键原因(使用层级分析): $$1.\ 任务未被正确提交或执行$$ - 检查`SERVICE_DICT[current_service_name]`是否存在对应的服务函数 - 确保`executor.submit()`成功提交任务,可在提交后立即添加日志验证 - 示例验证点: ```python try: service_func = SERVICE_DICT[current_service_name] print(f"准备提交服务函数: {service_func.__name__}") # 添加调试日志 future = executor.submit(service_func, node, current_front_id, global_data) except KeyError: print(f"服务 {current_service_name} 不存在!") # 关键错误捕获 ``` $$2.\ 线程生命周期问题$$ - `ThreadPoolExecutor`上下文管理器退出时会等待所有任务完成,但主线程可能提前退出 - 检查是否使用了`daemon`线程导致未完成的任务被终止 - 建议添加等待机制: ```python with executor: future = executor.submit(process_queue) future.result() # 显式等待初始任务完成 ``` $$3.\ 异常吞噬问题$$ - 如果`SERVICE_DICT`中的函数抛出未被捕获的异常,会导致`future.result()`抛出异常 - 在回调中加强异常处理: ```python def on_completion(...): try: result = future.result() except Exception as e: print(f"任务 {n} 执行时发生未捕获异常: {str(e)}") node[c_front_id]["node_state"] = TaskNodeState.FAILED.name # 明确失败状态 ``` $$4.\ 回调注册时序问题$$ - 确保在`future`状态改变前完成回调注册 - 检查是否存在竞态条件,可添加状态日志: ```python future.add_done_callback(lambda f: print("回调已注册")) future.add_done_callback(lambda f, n=current_front_id: on_completion(n, f)) ``` $$5.\ 工作流状态机缺陷$$ - 验证节点状态转换逻辑: ```python if node_status[successor] == TaskNodeState.READY.name: # 需要确保状态转换 ready_queue.append(successor) print(f"当前{successor}状态: {node_status[successor]}") # 添加状态日志 ``` 建议通过以下调试步骤定位问题: 1. 在`process_queue`开头添加`print("进入队列处理循环")` 2. 在`executor.submit()`前后添加提交日志 3. 使用`logging`模块代替`print`确保输出实时刷新 4. 在`on_completion`第一行添加`print("进入完成回调")`验证是否触发 典型问题场景示例: ```python # 错误场景:服务函数立即抛出异常 def bad_service(...): raise ValueError("未处理的异常") # 结果: # 1. future.result() 会抛出异常 # 2. 如果未在回调中捕获,会导致回调提前退出 # 3. 后继节点的依赖关系无法更新 ``` 修正方案: ```python def on_completion(...): try: result = future.result() # ...正常处理... except Exception as e: print(f"关键错误: {str(e)}") node[c_front_id]["node_state"] = TaskNodeState.FAILED.name # 显式处理失败节点的依赖关系 for successor in reverse_map[c_front_id]: dependencies[successor].discard(c_front_id) ``` 通过以上多维度排查,通常可以定位到回调未执行的根本原因。建议优先检查服务函数是否存在/正常执行,其次验证线程池的生命周期管理。
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值