Wait Handling

This method of using the interval timer allows you to set the timer and wait for the time to elapse. The job or task is prevented from executing until the interrupt occurs.

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿

￿ TECB

￿

 

 

￿

￿

￿ SETIME

￿

seconds , ￿ecbname

￿

￿ VSE ￿

￿

(1)

(2-12)

￿

￿

￿ WAIT

￿

￿ecbname

 

￿

￿

￿

￿

(1)

 

￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿

￿

￿ WAIT ,DINTVL = address

￿

￿

￿

￿

(2-12)

￿

￿

￿

￿

,BINTVL = address

￿

￿ MVS ￿ STIMER

￿

(2-12)

￿

￿

￿

￿

,TUINTVL= address

￿

￿

￿

￿

(2-12)

￿

￿

￿

￿

,TOD = address

￿

￿

￿

￿

(2-12)

￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

The VSE TECB is an event control block that records the status of the timer. When the interrupt is received, this condition is posted in the specified TECB. The WAIT macro tests the TECB status and determines if the interrupt has occurred.

The MVS STIMER macro provides basically the same facility. The difference is that, under VSE, you can insert code between the point where the timer is initiated (SETIME) and where the test for the interrupt is performed (WAIT). The wait is automatically built into the MVS STIMER macro. The WAIT parameter indicates that you do not want the coding below the macro to be executed during the time period. The DINTVL parameter is explained under ªRoutine Handlingº on page 287.

TTIMER Macro

The VSE and MVS TTIMER macros are compatible with each other:

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿ VSE ￿ TTIMER ￿ CANCEL ￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿ MVS ￿ TTIMER ￿ CANCEL ,TU ￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

The VSE time interval is expressed in binary in hundredths of a second, while under MVS, the interval is expressed in binary in timer units (one timer unit equals 26.04166 microseconds).

13.2.3.2Operator Communication Interrupts

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

￿

￿ STXIT

￿ OC, rou￿ine address ,

savearea

￿

￿ VSE ￿

￿

(0)

(1)

￿

￿

￿ EXIT

￿

OC

 

￿

￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿￿

288VSE to OS/390 Migration Workbook

Page 311 Page 313
Page 312
Image 312
IBM OS/390 manual Operator Communication Interrupts, Tecb Setime, VSE Ttimer Cancel MVS Ttimer Cancel ,TU, Exit
Page 311 Page 313

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.
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