A high-security software scheduling method based on function modules

Abstract

The application discloses a high-security software scheduling method based on a function module, relates to the field of civil aircraft onboard software, and comprises the following steps: constructing a three-level scheduling model comprising a sequence, a sequence and scheduling, and realizing fine management of the function module through a hierarchical structure of the sequence-sequence-scheduling; adopting a phase-based deterministic scheduling algorithm to ensure that the function module is strictly executed in a specified period and phase; and designing high-security features, including static resource verification and fault tolerance, modular execution atomization and the determinacy of an execution process. The application has the advantages that: through the construction of the three-level scheduling model, the adoption of the phase-based deterministic scheduling algorithm and the design of the high-security features, efficient and flexible task scheduling, static configuration verification and fault tolerance and modular atomized execution are realized, and the safety, reliability and maintainability of the onboard software scheduling are significantly improved.

Description

Technical Field

[0001] The present invention relates to the field of civil aircraft onboard software, and in particular to a high-security software scheduling method based on functional modules. Background Art

[0002] The onboard software architecture of civil aircraft has evolved from the first to the third generation. The current mainstream third-generation onboard software architecture adopts a "partitioned operating system + middleware + partitioned application" model, supporting the operation of multiple onboard applications on a single device. This achieves integrated software functionality and is widely used in modern large civil aircraft such as the Airbus A350 and Boeing 787. In terms of software scheduling technology, simple scheduling algorithms were initially used, executing tasks sequentially according to a pre-set order. This algorithm was unable to dynamically adjust the execution order based on task priority or real-time requirements. Subsequently, priority-based scheduling algorithms emerged, assigning a priority to each task. When scheduling tasks, the system prioritizes high-priority tasks. To meet the strict real-time requirements of onboard software, real-time scheduling algorithms have been widely used. Common ones include the Earliest Deadline First (EDF) algorithm and the Rate Monotonic Scheduling (RMS) algorithm. However, there are many defects in the existing technology, including poor task scheduling capabilities, cumbersome architecture adjustment processes, long adjustment cycles, slow responses, potential risks in code modifications, and inflexible resource allocation; resource design and configuration are difficult, the complexity brought about by the increase in functions makes the difficulty of system design and configuration increase exponentially, and there is a lack of effective automation tools; software system reconfigurability is difficult to achieve, the application and partition binding problem leads to too high binding between software and partitions, and the limitations of the reconstruction model make it difficult to adapt to the diverse reconfiguration requirements of future complex airborne systems; real-time accuracy assurance faces challenges, the increase in task complexity leads to scheduling delays, and there is a lack of standardized interfaces for tool chain integration; security and reliability need to be improved, and the security and reliability of the system need to be further enhanced. Summary of the Invention

[0003] In order to solve the above technical problems, a high-security software scheduling method based on functional modules is provided. This technical solution solves the problems raised in the above background technology in airborne software scheduling, such as low task scheduling capability, difficulty in resource design and configuration, poor reconfigurability of the software system, insufficient real-time and accuracy guarantees, and the need to improve safety and reliability.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0005] A high-security software scheduling method based on functional modules, comprising:

[0006] Build a three-level scheduling model including order, sequence, and scheduling, and achieve refined management of functional modules through the order-sequence-scheduling hierarchical structure;

[0007] Adopting a phase-based deterministic scheduling algorithm to ensure that functional modules are strictly executed in the specified cycle and phase;

[0008] Design high security features, including static resource verification and fault tolerance, modular execution atomicity, and determinism of the execution process.

[0009] Preferably, the slot module in the three-level scheduling model is a basic scheduling unit of the functional module, and each airborne software functional module is abstracted as a slot, and each slot includes a model, a scheduling cycle and a scheduling phase.

[0010] Preferably, the sequence module in the three-level scheduling model is a sequence arrangement within a single cycle, representing a set of sequence slots within a scheduling cycle. After each sequence has loaded the phase and cycle modules, the sequence module groups these sequences into a set and saves them.

[0011] Preferably, the scheduling module in the three-level scheduling model is a global scheduling management across cycles, which obtains the scheduling cycle and scheduling phase of each sequence by reading the configuration file, stores them in each sequence object, and generates a set;

[0012] The generated sequence set is converted into a sequence set to form a cross-cycle deterministic schedule.

[0013] Preferably, the phase-based deterministic scheduling algorithm includes a phase alignment mechanism, and the phase of each sequence must satisfy 0≤Phase <Cycles。

[0014] Preferably, the phase-based deterministic scheduling algorithm includes generating a cross-cycle scheduling table, which calculates the maximum period MajorPeriod in the scheduling algorithm and the basic time unit by reading a configuration file, and generates a scheduling table containing MajorCycles sequences.

[0015] Preferably, the high-security feature design includes static resource verification and fault tolerance, specifically cycle legitimacy verification and phase boundary checking, forcing the cycle to be an integer multiple of the minimum cycle and checking whether the phase exceeds the legal range.

[0016] Preferably, the high-security design includes modular execution atomicity and determinism of the execution process, specifically, there is no interruption during the execution of each application, and the order and dependencies of task execution are determined during system compilation.

[0017] Preferably, the function module parameters are statically configured through a CSV file, and a period divisibility check and a phase boundary check are introduced to intercept illegal parameters during the initialization phase.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention proposes a high-security software scheduling method based on functional modules, which realizes hierarchical management from single module parameter calculation to global cycle scheduling by decomposing the traditional flat task scheduling into a three-level model of rank-sequence-scheduling. The rank module abstracts each airborne software functional module into a rank, which contains basic scheduling information such as model, scheduling cycle and scheduling phase. At the beginning of each scheduling cycle, the sequence module sorts and arranges all qualified ranks according to their phase and cycle to form an ordered rank set. The scheduling module obtains the scheduling cycle and scheduling phase of each rank by reading the configuration file, and generates a cross-cycle deterministic scheduling table. New functional modules only need to modify the corresponding configuration file without adjusting the core logic of the scheduling algorithm. At the same time, hierarchical isolation makes it easy to locate scheduling anomalies. For example, a phase conflict in a sequence can be directly traced back to the rank parameter. In addition, the architecture designer has highly flexible scheduling control and only needs to make detailed adjustments to the scheduling table. There is no need to communicate and coordinate with the software engineer to modify the code repeatedly to quickly and accurately adjust the system scheduling order.

[0020] This paper proposes a high-security software scheduling method based on functional modules. By using the mathematical relationship between phase and period, a static scheduling table is generated to solve the uncertainty problem of existing real-time scheduling algorithms in complex periodic scenarios. The phase alignment mechanism ensures that the phase of each sequence satisfies 0≤Phase <Cycles的条件。跨周期调度表生成通过读取配置文件,计算出调度算法中的最大周期MajorPeriod,生成包含MajorCycles个序列的调度表。从而可确保功能模块在指定周期和相位严格执行,满足机载软件对确定性调度的严苛要求,并且通过静态调度表的生成方式,避免了运行时的动态调整,提高了系统的确定性和安全性,同时能够有效处理复杂的周期组合,确保即使在周期不同的情况下,系统也能保持调度的确定性和一致性。 BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the process of the present invention;

[0022] Figure 2 This is a flow chart of the three-level model diagram of rank-sequence-scheduling in the present invention;

[0023] Figure 3 It is a schematic diagram of the process of the sequence model diagram in the present invention;

[0024] Figure 4 It is a flow chart of the sequence model diagram in the present invention;

[0025] Figure 5 It is a flow chart of the scheduling model diagram in the present invention;

[0026] Figure 6 Schematic diagram of the dynamic event response process in the present invention. DETAILED DESCRIPTION

[0027] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are merely examples, and those skilled in the art may conceive of other obvious variations.

[0028] Reference Figure 1 As shown, a high-security software scheduling method based on functional modules includes:

[0029] Build a three-level scheduling model including order, sequence, and scheduling, and achieve refined management of functional modules through the order-sequence-scheduling hierarchical structure;

[0030] Adopting a phase-based deterministic scheduling algorithm to ensure that functional modules are strictly executed in the specified cycle and phase;

[0031] Design high security features, including static resource verification and fault tolerance, modular execution atomicity, and determinism of the execution process.

[0032] A three-level scheduling model was constructed, including three levels: order, sequence, and scheduling. The order module is the basic scheduling unit of the functional module, abstracting each onboard software functional module into a order. Each order includes basic scheduling information such as model, scheduling cycle, and scheduling phase. The sequence module is responsible for the arrangement of orders within a single cycle, representing a set of order slots within a scheduling cycle. After loading the phase, cycle, and other modules for each order, the sequence module groups these orders into sets and saves them. The scheduling module is a global scheduling management across cycles. By reading the configuration file, it obtains the scheduling cycle and scheduling phase of each order, stores them in each order object, and generates a set. At the same time, the generated order set is converted into a sequence set to form a deterministic scheduling table across cycles.

[0033] During its implementation, a phase-based deterministic scheduling algorithm ensures that functional modules are strictly executed at the specified cycle and phase. The algorithm includes a phase alignment mechanism to ensure that the phase of each sequence satisfies 0≤Phase <Cycles的条件。此外,算法还包括跨周期调度表生成,通过读取配置文件,计算出调度算法中的最大周期MajorPeriod,生成包含MajorCycles个序列的调度表。在调度执行流程中,每个MinorPeriod触发一次序列更新,按当前相位索引执行对应序位的功能模块,系统在编译时已将序位按相位顺序存入序列,确保调度顺序的确定性。

[0034] Thus, through the hierarchical function module scheduling model, hierarchical management from single module parameter calculation to global cycle arrangement is realized, and the scalability and maintainability of the system are improved. Secondly, the phase-based deterministic scheduling algorithm uses the mathematical relationship between phase and cycle to generate a static scheduling table, solving the uncertainty problem of existing real-time scheduling algorithms in complex cycle scenarios, and meeting the stringent requirements of airborne software for deterministic scheduling. Finally, the high-security static configuration and verification mechanism statically configures the function module parameters through the CSV file, introduces the cycle division verification and phase boundary check, intercepts illegal parameters in the initialization stage, prevents runtime failures, and improves the security and reliability of the system.

[0035] The slot module in the three-level scheduling model is the basic scheduling unit of the function module, which abstracts each airborne software function module as a slot, and each slot includes a model, a scheduling cycle, and a scheduling phase.

[0036] The construction of the slot module first needs to abstract and define each function module of the airborne software, mapping each function module to a slot. Then, the corresponding scheduling cycle and scheduling phase are configured for each slot, and the parameters used are usually statically configured through a configuration file to ensure that the specific scheduling information of each slot can be determined in the system initialization stage. Thus, the scheduling order and time point of each function module can be determined at compile time, thereby avoiding dynamic adjustment at runtime and improving the determinism and security of the system. During its overall use, by abstracting each function module as a slot, fine-grained management of the function modules is achieved, and the scheduling information of each slot can be independently configured and managed, improving the flexibility and maintainability of the system. Secondly, by statically configuring the scheduling cycle and scheduling phase, the execution order and time point of each function module can be determined at compile time, avoiding dynamic adjustment at runtime and reducing the uncertainty and potential security risks of system scheduling. In addition, the design of the slot module also makes it easier to extend and adjust functions, and adding new function modules only requires adding the corresponding slot information in the configuration file without modifying the core scheduling logic of the system, thereby improving the scalability and development efficiency of the system.

[0037] The sequence module in the three-level scheduling model arranges the slots within a single cycle, representing a collection of slot slots within a scheduling cycle. After the phase and cycle modules are loaded, the sequence module groups these slots into a collection and saves them.

[0038] The scheduling cycle and phase information for each sequence is read from the configuration file. Based on this information, the sequence module will then sort and arrange all eligible sequences according to their phase and cycle at the beginning of each scheduling cycle to form an ordered sequence set. This set represents all functional modules that need to be executed within that scheduling cycle and their execution order. This allows the sequence module to work in conjunction with the scheduling module to ensure that the functional modules within each scheduling cycle can be executed in the predetermined order and time point. At the beginning of each scheduling cycle, the sequence module will select the sequences to be executed from the saved sequence set based on the current phase and time point, and pass them to the scheduling module for execution. This design ensures that each functional module is strictly executed within the specified cycle and phase, avoiding scheduling conflicts and uncertainty in the execution order.

[0039] During its operation, by arranging the sequences into an ordered set, the sequence module can accurately control the execution order and timing of the functional modules within each scheduling cycle, thereby improving the scheduling accuracy and reliability of the system. Secondly, by combining the sequence module with the configuration file, it realizes the combination of static configuration and dynamic scheduling, allowing the system to determine the execution order and time point of each functional module at compile time, avoiding dynamic adjustments at runtime, and reducing the uncertainty and potential safety hazards of system scheduling. In addition, the design of the sequence module also makes it easier to expand and adjust the system's functions. New functional modules only need to add the corresponding sequence information in the configuration file without modifying the core scheduling logic of the system, thereby improving the scalability and development efficiency of the system.

[0040] The scheduling module in the three-level scheduling model is a global scheduling management across cycles. It obtains the scheduling cycle and scheduling phase of each sequence by reading the configuration file, stores them in each sequence object, and generates a set.

[0041] The generated sequence set is converted into a sequence set to form a cross-cycle deterministic schedule.

[0042] In the three-level scheduling model, the scheduling module, as the global scheduling management component across cycles, is responsible for reading the scheduling period and phase for each rank from the configuration file and storing them in each rank object. At runtime, the scheduling module first parses the configuration file to obtain the scheduling parameters for all functional modules in the system, including the scheduling period and phase for each rank. These parameters are determined at system compile time, ensuring determinism and predictability in the scheduling process. The scheduling module then stores these parameters in each rank object, forming an ordered set of ranks.

[0043] Next, the scheduling module will further organize the generated sequence set into a sequence set, forming a cross-period deterministic scheduling table. This scheduling table is the scheduling blueprint of the system in the entire running period, ensuring that each functional module is strictly executed at the specified period and phase. The scheduling module calculates the maximum period MajorPeriod in the scheduling algorithm by reading the parameters in the configuration file, and generates a scheduling table containing multiple sequences. This scheduling table is used to guide the execution order and time point of the functional modules during system operation, ensuring efficient and stable operation of the system.

[0044] During its entire operation, the scheduling module realizes the combination of static configuration and dynamic scheduling by reading scheduling parameters from the configuration file and generating a scheduling table, ensuring efficient and stable operation of the system. Secondly, the scheduling module ensures that each functional module is strictly executed at the specified period and phase by generating a cross-period deterministic scheduling table, improving the scheduling accuracy and reliability of the system. In addition, the design of the scheduling module also makes it easier for the system to expand and adjust functions, and the addition of new functional modules only requires the addition of corresponding sequence information in the configuration file without modifying the core scheduling logic of the system, thereby improving the scalability and development efficiency of the system.

[0045] The phase-based deterministic scheduling algorithm includes a phase alignment mechanism, and the phase of each sequence must satisfy 0≤Phase<Cycles.

[0046] By setting a phase parameter for each functional module (i.e. sequence) during the system configuration phase, the parameter must be within the range of 0 to Cycles-1. Cycles represents the total number of phases in a scheduling period, which is usually determined by the scheduling period of the system and the execution time of the functional module. That is, the execution time point of each functional module can be determined at compile time, which is a key design element of the phase alignment mechanism, ensuring that the phase of each sequence satisfies the condition 0≤Phase<Cycles, thereby avoiding dynamic adjustment at runtime, reducing the uncertainty and potential security risks of system scheduling, and improving the determinism and security of the system. If it is found that the phase value of a certain sequence exceeds the range, the system will intercept and report an error during the initialization phase, thereby preventing runtime failures. The static verification mechanism effectively improves the safety and reliability of the system. During its operation, the phase alignment mechanism also ensures that the phase value of each sequence is within the specified range, avoiding scheduling conflicts and uncertainty of execution order caused by incorrect phase values.

[0047] The phase-based deterministic scheduling algorithm includes cross-period scheduling table generation, which calculates the maximum period MajorPeriod in the scheduling algorithm by reading the configuration file, and generates a scheduling table containing MajorCycles sequences.

[0048] The scheduling period and phase parameters for each functional module are defined in the configuration file. These parameters are read during the initialization phase, and an algorithm is used to calculate the maximum scheduling period across all order slots, known as the MajorPeriod. The system also determines a base time unit, typically the lowest common multiple of the scheduling period. Based on the period and phase parameters of each order slot, the system assigns it to the corresponding position in the scheduling table, ensuring that each order slot is strictly executed within the specified period and phase. This static scheduling table generation method avoids dynamic adjustments at runtime, improving system determinism and security. By statically configuring and pre-generating the scheduling table, the system can determine the execution order and timing of each functional module at compile time, avoiding dynamic adjustments at runtime and reducing system scheduling uncertainty and potential security risks. Furthermore, it can effectively handle complex period combinations, ensuring that the system maintains scheduling determinism and consistency even with varying periods. Furthermore, this static scheduling table generation method improves system maintainability and scalability. Adding new functional modules requires only adding the corresponding parameters to the configuration file, without modifying the system's core scheduling logic, thus simplifying system development and maintenance.

[0049] The high-security design includes static resource verification and fault tolerance, specifically cycle legitimacy verification and phase boundary checking, forcing the cycle to be an integer multiple of the minimum cycle and checking whether the phase exceeds the legal range.

[0050] In high-security design, static resource verification and fault-tolerance mechanisms are crucial for ensuring system stability and security. Cycle validity verification ensures that the scheduling period of each functional module is an integer multiple of the system's minimum period, thereby avoiding task conflicts and scheduling chaos caused by improper cycle settings. By rigorously verifying the cycle parameters of each sequence during system initialization, the system can promptly detect and intercept non-compliant configurations, preventing runtime errors.

[0051] The phase boundary check verifies the phase parameter of each sequence to ensure that its value is within the legal range, that is, 0≤Phase <Cycles。从而防止了因相位设置错误而导致的调度越界问题,避免了可能的内存访问错误和系统崩溃。通过在配置文件读取和调度表生成过程中进行相位参数的校验,也能够在早期阶段发现并纠正配置错误,从而提高系统的可靠性和安全性。

[0052] Static resource verification, in conjunction with the fault-tolerance mechanism, enables parameter verification during system initialization, identifying and correcting configuration errors early on, thus avoiding scheduling issues and system crashes caused by parameter errors during runtime. Furthermore, this improves system security and reliability, ensuring that each functional module executes strictly within the predetermined cycle and phase, avoiding task conflicts and scheduling disruptions. Furthermore, the static verification mechanism simplifies system maintenance and debugging, allowing developers to quickly locate and fix issues using configuration files, improving development and maintenance efficiency.

[0053] The high-security design includes modular execution atomicity and deterministic execution process. Specifically, there is no interruption during the execution of each application, and the order and dependencies of task execution are determined during system compilation.

[0054] The execution order and dependencies of each functional module are defined using static configuration files (such as CSV files). These configuration files are read and parsed during system compilation to generate a fixed schedule. The schedule details the execution order of each functional module within each scheduling cycle and phase, ensuring that each module's execution is not interrupted by other modules or external events. This allows the execution order and dependencies of all tasks to be determined at compile time, avoiding dynamic adjustments and potential scheduling conflicts at runtime.

[0055] During its implementation, the configuration file undergoes rigorous validation during initialization, including period divisibility checks and phase boundary checks, to ensure the validity and consistency of all configuration parameters. A static schedule is then generated based on the configuration file, and each functional module is executed strictly according to this schedule at runtime. Because the execution order and dependencies of all tasks are determined at compile time, the system does not require dynamic scheduling decisions during execution, thus avoiding the uncertainty and potential risks associated with such decisions.

[0056] This allows task execution to be determined statically at compile time, avoiding the uncertainty and potential risks associated with dynamic scheduling at runtime and improving system reliability and security. Furthermore, since each application is not interrupted during execution, the integrity and consistency of task execution is guaranteed, preventing inconsistent execution states or data errors caused by interruptions. Furthermore, this simplifies system development and maintenance. Developers can quickly define and adjust task execution order through static configuration files without having to modify complex scheduling algorithms and logic, thereby improving development efficiency and system maintainability.

[0057] Function module parameters are statically configured through CSV files, and period divisibility check and phase boundary check are introduced to intercept illegal parameters during the initialization phase.

[0058] A configuration file (CSV format) defines the scheduling parameters for each functional module, including key information such as the scheduling period and scheduling phase. This allows the system to determine the scheduling behavior of all functional modules at compile time rather than runtime, thus avoiding security risks associated with dynamic configuration at runtime, such as memory tampering or parameter anomalies. During runtime, the system first reads the CSV configuration file, parses the functional module parameters, and performs rigorous validation. Period divisibility checks ensure that the scheduling period of each functional module is an integer multiple of the minimum period, avoiding task conflicts or scheduling confusion caused by improper period settings. Phase boundary checks ensure that the scheduling phase of each functional module is within the legal range, preventing memory access errors or other anomalies caused by incorrect phase settings. By performing these checks during the initialization phase, illegal parameters are promptly detected and blocked, ensuring that the scheduling parameters of all functional modules meet expectations, thereby improving system stability and security.

[0059] Therefore, through the design of static configuration and strict verification, static configuration avoids the uncertainty and potential risks brought by dynamic adjustment at runtime, so that the system scheduling behavior is determined at compile time, improving the predictability and reliability of the system. The period divisibility check and phase boundary check can intercept illegal parameters during the initialization phase, preventing system failures or safety hazards caused by configuration errors, and enhancing the security and stability of the system.

[0060] In summary, the advantages of the present invention are: by constructing a three-level scheduling model, adopting a phase-based deterministic scheduling algorithm and designing high-security features, efficient and flexible task scheduling, static configuration verification and fault tolerance, and modular atomic execution are achieved, which significantly improves the security, reliability and maintainability of onboard software scheduling.

[0061] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-security software scheduling method based on functional modules, characterized in that: include: Build a three-level scheduling model including order, sequence, and scheduling, and achieve refined management of functional modules through the order-sequence-scheduling hierarchical structure; Adopting a phase-based deterministic scheduling algorithm to ensure that functional modules are strictly executed in the specified cycle and phase; Design high-security features, including static resource verification and fault tolerance, modular execution atomicity, and deterministic execution process; The sequence slot module in the three-level scheduling model is the basic scheduling unit of the functional module, abstracting each onboard software functional module into a sequence, each sequence including the model, scheduling cycle and scheduling phase; The sequence module in the three-level scheduling model is a sequence arrangement within a single cycle, representing a set of sequence slots within a scheduling cycle. After each sequence has loaded the phase and cycle modules, the sequence module groups these sequences into a set and saves them. The scheduling module in the three-level scheduling model is a global scheduling management across cycles. It obtains the scheduling cycle and scheduling phase of each sequence by reading the configuration file, stores them in each sequence object, and generates a set. The generated sequence set is converted into a sequence set to form a cross-cycle deterministic schedule.

2. A high-security software scheduling method based on functional modules according to claim 1, characterized in that: The phase-based deterministic scheduling algorithm includes a phase alignment mechanism, and the phase of each sequence must satisfy 0≤Phase <Cycles。 3. A high-security software scheduling method based on functional modules according to claim 2, characterized in that: The phase-based deterministic scheduling algorithm includes generating a cross-cycle scheduling table. By reading a configuration file, the maximum period MajorPeriod in the scheduling algorithm is calculated, and a scheduling table containing MajorCycles sequences is generated.

4. A high-security software scheduling method based on functional modules according to claim 3, characterized in that: The high-security design includes static resource verification and fault tolerance, specifically cycle legitimacy verification and phase boundary checking, forcing the cycle to be an integer multiple of the minimum cycle and checking whether the phase exceeds the legal range.

5. The high-security software scheduling method based on functional modules according to claim 4, characterized in that: The high-security design includes modular execution atomicity and deterministic execution process. Specifically, there is no interruption during the execution of each application, and the order and dependencies of task execution are determined during system compilation.

6. A high-security software scheduling method based on functional modules according to claim 5, characterized in that: Function module parameters are statically configured through CSV files, and period divisibility check and phase boundary check are introduced to intercept illegal parameters during the initialization phase.

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