The message passing interface (MPI) has become a de facto standard for programming models of highperformance computing, but its rich and flexible interface semantics makes the program easy to generate communication de...The message passing interface (MPI) has become a de facto standard for programming models of highperformance computing, but its rich and flexible interface semantics makes the program easy to generate communication deadlock, which seriously affects the usability of the system. However, the existing detection tools for MPI communication deadlock are not scalable enough to adapt to the continuous expansion of system scale. In this context, we propose a framework for MPI runtime communication deadlock detection, namely MPI-RCDD, which contains three kinds of main mechanisms. Firstly, MPI-RCDD has a message logging protocol that is associated with deadlock detection to ensure that the communication messages required for deadlock analysis are not lost. Secondly, it uses the asynchronous processing thread provided by the MPI to implement the transfer of dependencies between processes, so that multiple processes can participate in deadlock detection simultaneously, thus alleviating the performance bottleneck problem of centralized analysis. In addition, it uses an AND⊕OR model based algorithm named AODA to perform deadlock analysis work. The AODA algorithm combines the advantages of both timeout-based and dependency-based deadlock analysis approaches, and allows the processes in the timeout state to search for a deadlock circle or knot in the process of dependency transfer. Further, the AODA algorithm cannot lead to false positives and can represent the source of the deadlock accurately. The experimental results on typical MPI communication deadlock benchmarks such as Umpire Test Suit demonstrate the capability of MPIRCDD. Additionally, the experiments on the NPB benchmarks obtain the satisfying performance cost, which show that the MPI-RCDD has strong scalability.展开更多
Implantable materials have broad applications in tissue engineering and in vivo sensors. It is essential to know the detailed information of the implantable materials during their degradation. In this paper, we develo...Implantable materials have broad applications in tissue engineering and in vivo sensors. It is essential to know the detailed information of the implantable materials during their degradation. In this paper, we developed a method to monitor the degradation process of a well-used biomaterial, poly（lactide-co- glycolide） （PLGA） by taking advantage of inverse opal structure. We found that mass loss, molecular weight and glass transition temperature of PLGA during the degradation process in Hank＇s artificial body fluid can be in situ monitored bv measuring the ootical orooerties of PLGA inverse ooal.展开更多
基金This work was supported by the National Key Research and Development Program of China under Grant No. 2017YFB0202003。
文摘The message passing interface (MPI) has become a de facto standard for programming models of highperformance computing, but its rich and flexible interface semantics makes the program easy to generate communication deadlock, which seriously affects the usability of the system. However, the existing detection tools for MPI communication deadlock are not scalable enough to adapt to the continuous expansion of system scale. In this context, we propose a framework for MPI runtime communication deadlock detection, namely MPI-RCDD, which contains three kinds of main mechanisms. Firstly, MPI-RCDD has a message logging protocol that is associated with deadlock detection to ensure that the communication messages required for deadlock analysis are not lost. Secondly, it uses the asynchronous processing thread provided by the MPI to implement the transfer of dependencies between processes, so that multiple processes can participate in deadlock detection simultaneously, thus alleviating the performance bottleneck problem of centralized analysis. In addition, it uses an AND⊕OR model based algorithm named AODA to perform deadlock analysis work. The AODA algorithm combines the advantages of both timeout-based and dependency-based deadlock analysis approaches, and allows the processes in the timeout state to search for a deadlock circle or knot in the process of dependency transfer. Further, the AODA algorithm cannot lead to false positives and can represent the source of the deadlock accurately. The experimental results on typical MPI communication deadlock benchmarks such as Umpire Test Suit demonstrate the capability of MPIRCDD. Additionally, the experiments on the NPB benchmarks obtain the satisfying performance cost, which show that the MPI-RCDD has strong scalability.
基金supported in by the National Natural Science Foundation of China(Nos.51273056,21202091, 5121010502,and 21074031)Innovation Fellowship Foundation of Heilongjiang University(No.Hdtd2010-11)
文摘Implantable materials have broad applications in tissue engineering and in vivo sensors. It is essential to know the detailed information of the implantable materials during their degradation. In this paper, we developed a method to monitor the degradation process of a well-used biomaterial, poly（lactide-co- glycolide） （PLGA） by taking advantage of inverse opal structure. We found that mass loss, molecular weight and glass transition temperature of PLGA during the degradation process in Hank＇s artificial body fluid can be in situ monitored bv measuring the ootical orooerties of PLGA inverse ooal.
