Hitachi, Ltd.

Hitachi Software Engineering Company, Ltd.

Hitachi Electronics Services Co. Ltd.

Fujio Fujita

Toshio Hirosawa

Shigeru Sasaki

Atsushi Ueoka

Kazuyuki Nakamura

Motohide Kokunishi

Tadashi Yamagishi

Masahiko Ishimaru

Yoshikazu Ichikawa

Michio Hirano

Kaoru Kozuma

Hideki Namba

Kazuo Takaragi

Akinobu Shimada

Masafumi Nozawa

Masaaki Shimizu

Takashi Nishikado

Toshiyuki Ukai

Yasuhiro Ishii

Tutomu Itoh

Tokuhiro Tsukiyama

Toshifumi Nishimura

Katsuharu Kakuse

Kiyoshi Yata

Tsutomu Itoh

Nobuo Yamamoto

Michio Tandai

Masaaki Hama

Yasushi Kuba

Tutomo Itoh

When the OS judges that a read request to the secondary storage device from the user process is the sequential access, the OS judges whether prefetching is to be stopped before the data succeeding to the data designated by the request is prefetched, so as to decrease replacement of data prefetched to the main memory by other data before the data is used. The judgment is executed to prevent that succeeding data from being replaced by other data after the succeeding data is prefetched to the cache area in the main memory. That is, it is judged whether the data requested by the read request has already been prefetched, and has already been replaced by other data before the requested data is used by the user process, if the requested data has been prefetched. When these two conditions are met, prefetch is useless. The prefetching accompanying this read request is not executed, the prefetch stop flag is set, and prefetching is prohibited to the succeeding sequential access by this prefetch stop flag. The technology is also disclosed which controls allocation of the cache entries so that a cache entry which holds prefetched data is not used to hold other data before the data is used.

Data prefetch control method for main storage cache for protecting

In an information processing debugging apparatus, a debugger owns a debug information adding element and a data with type access instructing element. The debug information adding element gives data type symbol information of a data type from a debug information object file to be used by an information processing program in a program object file to be debugged. The typed data access instructing element instructs an access operation by using a variable symbol of the information process program and an added data type symbol information as a variable having a data type where an operator designates a variable of the information program. Such an information processing program which is not formed by a debug option is symbolically debugged without increasing the memory capacity. A practical information processing program such as a library which is not directly related to debugging operation can also be symbolically debugged.

Debugging method and debugger

In an electronic mail associated type computer system network equipped with a computer system for executing a job and a general-purpose electronic mail system, a user of an electronic mail can freely recognize a condition of an execution result of a job performed in the computer system and a job execution result. Also, these results are available from a desired output device for the user. When a mail processing unit employed in the computer system analyzes a mail statement about the job execution derived from the electronic mail system, and the job execution is completed, this mail processing unit sends to the electronic mail system, such a mail statement for the completion of the job execution containing information about fail/safe execution result. Upon receipt of this report, the user designates the output device into a response mail so as to output the job execution result from the designated output device.

Computer system and job transfer method using electronic mail system

In an arrangement of a mail terminal 1, an electronic mail system 2, a job control terminal 4, and a computer system 3, a user makes a proposal of a file operation via a mail by way of the mail terminal 1. The electronic mail system 2 stores therein the proposal mail, exchanges this proposal mail with the job control terminal 4, and furthermore distributes a file operation result to the respective mail terminals. The job control terminal 4 receives a mail from the electronic mail system 2, and interprets the proposal mail, thereby executing a conversion from a mail ID into a host ID, a judgement of an access authorization with respect to the designated file, and a production of an instruction to the computer process system 3. Furthermore, an execution host computer is selected by monitoring operation conditions of the host computers. When the file operation result is sent from the computer process system 3, a mail containing this file operation result is produced, and the resultant mail is sent to the electronic mail system 2. The computer system 3 interprets a command issued from the job control terminal 4, thereby executing a reading operation from the designated file, a writing operation to the designated file, and a reading operation of a file name list.

Electronic mail drive type computer system and file operation method

A job control terminal creates a unit configuration table indicating the configuration of units connected to each of a plurality of processors in a multi-processor system. The job control terminal also creates an operating state table indicating an operating state of each processor including a CPU using ratio, I/O using ratio, memory using ratio, response time, and so on. When the job control terminal receives electronic mail for requesting job execution from a user through an electronic mail terminal, the job control terminal selects a processor assigned to execute the requested job based on the unit configuration table and the operating state table. When it is determined from the states of the processors that the requested job cannot be executed, information indicating that the job is unacceptable is transmitted from the job control terminal to the electronic mail terminal.

Method and apparatus for having a processor execute a job utilizing an

In an information processing system including a file shared by computer systems each having a central processing system and a main memory, a method for controlling access to the shared file includes a step of storing blocks read from the file into the main memory when the blocks of the file are updated, and a step of comparing at least a portion of the blocks held in a cache memory with at least a portion of the blocks stored in the main memory. When the comparison of at least the portion of the blocks held in the cache memory with at least the portion of the blocks stored in the main memory indicates mismatching, the block is read from the file into the main memory, and when the comparison indicates matching, the block of the main memory is updated. The data to be updated may be in a resident area, an input/output buffer or a same area.

Method for controlling access to a shared file and apparatus therefor

In an information processing system having an upper rank apparatus and an external storage device which performs transmission and reception of data between the storage device and the upper rank apparatus, at least one of encryption and decryption of the data by use of an algorithm controlled by a desired data key is performed in the external storage device, while generation, encryption and decryption of the data key are performed on the upper rank apparatus side. By this configuration, the burden of the upper rank apparatus is largely reduced and the secrecy of data stored in the external storage device can be surely kept without spoiling the throughput of the whole system.

File encryption method and file cryptographic system

Growing community of inventors

Yokohama, Japan

Fujio Fujita