WO2014187166A1

WO2014187166A1 - Communication method and apparatus among multiple processes in star structure

Info

Publication number: WO2014187166A1
Application number: PCT/CN2014/071196
Authority: WO
Inventors: 张飞; 李香富; 张炽成
Original assignee: 福建联迪商用设备有限公司
Priority date: 2013-05-24
Filing date: 2014-01-23
Publication date: 2014-11-27
Also published as: CN103294541B; CN103294541A

Abstract

The present invention proposes a communication method and apparatus among multiple processes in a star structure. In a thread, a poll function is used to ingeniously combine a control link and a communications link and perform centralized monitoring; in this way, as seen in a macroscopic scale, one thread can communicate with multiple threads or processes synchronously. The communications link is used for specific interaction and use of function information, and the control link is used for specific interaction and use of control information. By means of the present invention, a problem in a one-to-multiple model in multiple-process communication that a common communication method cannot perform synchronous communication between one process or thread and other multiple threads or processes is solved; meanwhile, a method in which a control link is used to instruct a thread to actively end a thread operation from inside the thread provides an asynchronous thread termination method.

Description

Multi-process communication method and device with star structure

Technical field

The present invention relates to the field of communications, and in particular to a multi-process communication method and apparatus for a star structure.

Background technique

In Bluetooth-related multi-threaded programming, there is a need for a process that requires data interaction with other multiple processes or threads, and the amount of data exchanged is small, but the time of data interaction is random, that is, The blocking listener waits for the communication link; it needs to be able to terminate the thread asynchronously. In general, to communicate with multiple processes or threads at the same time, each communication link needs to establish a process or thread to block the waiting event, so the program is more complicated. Asynchronous termination of threads generally uses pthread_cancel to notify the thread to terminate, or to terminate the thread in a thread by means of global variables, etc., but there are problems such as resource cleanup or inefficient execution when the thread terminates. In severe cases, even A situation where the program terminated unexpectedly.

1. At present, multi-process communication usually uses pipes, message queues, shared memory, semaphores, sockets, etc., and simultaneously communicates with multiple processes or threads. Each communication link establishes a process or thread to block. Wait for an event to occur.

2. Thread termination generally uses pthread_cancel to notify the thread to terminate, or to terminate the thread by looping through the query mode through global variables.

Commonly used multi-process communication methods (pipe, message queue, shared memory, semaphore, socket, etc.), generally use a blocking method to spend a process or thread to block the occurrence of waiting events, and if it is non-blocking then You need to use the way of query to repeatedly query the occurrence of the event. The former will increase the number of program processes or threads, increasing the complexity of the program, while the latter will waste additional system resources on the occurrence of query events. In addition, in multi-threaded programming, asynchronous termination threads typically terminate threads asynchronously using pthread_cancel or global variables, or have resource cleanup issues or wasted additional system resources. FIG. 1 is a schematic diagram showing the structure of a general real-time multi-process communication model.

Summary of the invention

The present invention provides a multi-process communication invention suitable for a star structure similar to a network topology, in which a poll function is used in a thread to skillfully combine a control link and a communication link for centralized monitoring. From a macro perspective, a thread can communicate with multiple threads or processes at the same time. The communication link is used for the interactive use of specific function information, and the control link is used for the interactive use of specific control information. Through the invention, the problem that the general communication method in the one-to-many model in the multi-process communication cannot simultaneously communicate with other multiple threads or processes in one process or thread is solved, and the thread is notified from the thread through the control link. A method of actively terminating thread operations internally provides a way to terminate threads asynchronously.

The present invention includes three parts of a controller, a processor, and a functional module as a whole. First, the controller starts the processor and establishes a control link with the processor, and then the processor blocks the controller link between the controller and the processor and the functional link between the processor and other functional modules with the poll; Through the control link, the processor can be controlled to add and delete communication links and monitoring functions between the processor and the function module, and the processor can be shut down through the control link; other functional modules are connected through a new communication link. Specific functional operational interactions.

The invention uses a combination of a poll function and a socket to simultaneously monitor the handles of multiple communication links in a thread or process, and can dynamically increase and delete the monitored communication link handles, avoiding the general method. A communication link consumes a process or thread problem in a blocking mode, which reduces the complexity of the program and does not require the use of a query method to generate additional system overhead. At the same time, through the established control link, the notification thread actively terminates the thread from within the thread, and provides a method for asynchronously terminating the thread, which simplifies the process of cleaning the resource when the thread is asynchronously terminated, and avoids the extra system overhead caused by the query mode.

DRAWINGS

The above and other aspects and advantages of the present invention will become more apparent from the following detailed description of exemplary embodiments of the invention.

Figure 1: Schematic diagram of the general real-time multi-process communication model structure;

2 is a schematic structural diagram of a multi-process communication model of a star structure according to an embodiment of the present invention;

Figure 3 is a diagram showing a multi-process communication model framework of a star structure of the present invention;

Figure 4 is a flow chart showing the process of variation of the present invention during the running of the program.

detailed description

In the following, the invention will now be described more fully hereinafter with reference to the accompanying drawings in which FIG. However, the invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

As shown in FIG. 2, it is a schematic diagram of a multi-process communication model structure of a star structure according to the present invention. It can be seen from the model comparison diagram that a general real-time multi-process communication invention is required, and if it is required to simultaneously perform with four functional modules. In the interaction, the main process needs to establish four sub-threads to interact, and the present invention organically combines the control link and the functional link through the poll function, and simultaneously monitors multiple communication links in one thread. The handle, the work that needs to be established by multiple threads or processes is simplified in one thread, and the monitored communication link handle can be dynamically added and deleted, avoiding the cost of a communication link in the blocking mode. A process or thread problem does not require the use of query methods to generate additional system overhead, which reduces the complexity of the program and increases the flexibility of the program. A control link is established between the main process (controller) and the child thread (processor). The main process can notify the sub-thread to actively terminate the thread from the inside of the thread through the control link, simplifying the process of cleaning the resource when the thread is asynchronously terminated, and avoiding the query mode. Additional overhead.

As shown in FIG. 3, it is a multi-process communication model framework diagram of a star structure of the present invention.

The invention can be divided into three parts as a whole: a controller part, a processor part and a function module.

The controller part: the process, is responsible for starting the processor thread and terminating the processor thread, controlling the establishment and deletion of the communication link between the processor and other modules through the control link, and terminating the related operations;

Processor part: thread, controlled by the controller, is responsible for monitoring the communication link handle and control link handle of each function module, interacting with the controller and each functional module, and performing related processing;

Functional module part: A thread or process, a specific functional module, interacts with the processor through a communication link.

As shown in FIG. 4, after the implementation of the present invention, in the process of running the program, there are several flow chart of the change process. Note that in Figure 4, the main process (controller) is referred to as the main process, and the sub-thread (processor) is referred to as the sub-thread.

Procedure 1: The main process creates a new sub-thread and establishes a control link with the sub-process; the sub-thread adds the control link handle to the poll function listener set for monitoring, and processes the control information from the main process at any time.

Process 2: The main process controls the sub-thread to establish a communication link with the function module through the control link, and the sub-thread adds the communication link handle to the poll function listener set for monitoring, and then the sub-thread can process the communication chain from the listener at any time. The interaction information of the road is gone.

Process 3: The main process controls the sub-thread to disconnect the communication link with the function module through the control link, and the sub-thread deletes the communication link handle from the poll function monitoring set, and no longer listens.

Process 4: The main process notifies the child thread to end by controlling the link, that is, shutting down the processor.

The features of the invention are as follows:

1, the combination of socket and poll function, making the mechanism flexible.

2. There is a need to terminate the thread asynchronously. Through the established communication link, the external termination thread in general is converted into a notification thread to actively end from inside the thread.

3. The present invention is applicable to a multi-process communication model similar to a star structure in a network topology.

4. The communication time of each communication link is random.

The invention has been adopted in the Bluetooth module on the POS machine and tested:

1) The activation and termination of the pairing request thread can be controlled by the opening and closing operations of the Bluetooth device, that is, the controller in the invention model enables the processor and turns off the processor, and the process of shutting down the processor is to notify the thread to terminate through the control link.

2) By initiating the pairing request operation, the communication link monitored by the thread can be dynamically added and deleted, that is, the communication link function between the processor and the function module is established and deleted in the invention model.

3) By adopting the invention, the method of asynchronously terminating the thread by means of a method of notifying the thread termination by pthread_cancel or a method of looping through the query in a thread by means of a global variable or the like has a great robustness and stability. Improvement.

4) Apply this invention to the Bluetooth module pairing function on the POS machine, and the function is stable and normal in the strength test up to 4000 times.

The above description is only an embodiment of the present invention and is not intended to limit the present invention. The invention is susceptible to various modifications and changes. Any modifications, equivalents, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

A multi-process communication method of a star structure, characterized in that:

First, the controller starts the processor and establishes a control link with the processor, and then the processor blocks the controller link between the controller and the processor and the functional link between the processor and other functional modules with the poll; Through the control link, the processor can be controlled to add and delete communication links and monitoring functions between the processor and the function module, and the processor can be shut down through the control link; other functional modules are connected through a new communication link. Specific functional operational interactions.

2. A multi-process communication method for a star structure according to claim 1, wherein:

During the operation of the method, the following changes are made:

Process 1: The controller creates a new processor and establishes a control link with the child process; the processor adds a control link handle to the poll function listener set for monitoring, and processes control information from the controller at any time;

Process 2: The controller establishes a communication link with the function module through the control link control processor, and the processor adds the communication link handle to the poll function monitoring set for monitoring, and the processor can then process the communication chain from the listener at any time. Road interaction information;

Process 3: The controller controls the processor to disconnect the communication link with the function module by controlling the link, and the processor deletes the communication link handle from the poll function monitoring set, and no longer listens;

Process 4: The controller notifies the processor to end by controlling the link, ie, shutting down the processor.

3. A multi-process communication device of a star structure, characterized in that:

The device is divided into three parts: a controller part, a processor part and a function module;

Controller part: responsible for the process, responsible for starting the processor thread and terminating the processor thread, controlling the establishment and deletion of the communication link between the processor and other modules through the control link, and terminating the related operations;

Processor part: responsible for the thread, the controller controls its life process, is responsible for monitoring the communication link handles and control link handles established by each function module, interacting with the controller and each functional module, and performing related processing;

Function module: responsible for threads or processes, a specific function module, and the processor interacts through the communication link.

4. A multi-process communication device with a star structure according to claim 3, wherein:

The communication method of the communication device is:

First, the controller starts the processor and establishes a control link with the processor, and then the processor blocks the controller link between the controller and the processor and the functional link between the processor and other functional modules with the poll; Through the control link, the processor can be controlled to add and delete communication links and monitoring functions between the processor and the function module, and the processor can be shut down through the control link; other functional modules are connected through a new communication link. Specific functional operational interactions.

5. A multi-process communication method for a star structure according to claim 4, wherein:

During the operation of the method, the following changes are made:

Process 1: The controller creates a new processor and establishes a control link with the child process; the processor adds a control link handle to the poll function listener set for monitoring, and processes control information from the controller at any time;

Process 2: The controller establishes a communication link with the function module through the control link control processor, and the processor adds the communication link handle to the poll function monitoring set for monitoring, and the processor can then process the communication chain from the listener at any time. Road interaction information;

Process 3: The controller controls the processor to disconnect the communication link with the function module by controlling the link, and the processor deletes the communication link handle from the poll function monitoring set, and no longer listens;

Process 4: The controller notifies the processor to end by controlling the link, ie, shutting down the processor.