HP OpenVMS Systems Documentation

The SHOW RESOURCE command has the following new qualifier:

The SHOW SPINLOCKS command has the following new qualifier:

The SHOW SUMMARY command has the following new qualifier:

The OpenVMS Version 7.3 software release includes the new Spinlock Tracing utility. With the implementation of this utility, you can now tell which spinlock is heavily used, and who is acquiring and releasing the contended spinlocks. The Spinlock Tracing utility allows a characterization of spinlock usage, as well as collection of performance data for a given spinlock on a per-CPU basis. The tracing ability can be enabled or disabled while the system is running, allowing the collection of spinlock data for a given period of time without system interruption.

To use the Spinlock Tracing utility, SDA has implemented new commands and qualifiers. These SDA commands and qualifiers are described as follows:

5.15.1 SPL LOAD

This command loads the SPL$DEBUG execlet. This must be done prior to starting spinlock tracing. It has no qualifiers.

5.15.2 SPL SHOW COLLECT

This command displays the data collected for a specific spinlock. It has no qualifiers.

5.15.3 SPL SHOW TRACE

This command displays spinlock tracing information. Table 5-3 shows the qualifiers for this command.

This command accumulates information for a specific spinlock. Table 5-4 shows the qualifiers for this command:

This command enables spinlock tracing. Table 5-5 shows the qualifiers for this command.

This command stops the spinlock collection, but does not stop spinlock tracing. It has no qualifiers.

5.15.7 SPL STOP TRACE

This command disables spinlock tracing, but it does not deallocate the trace buffer. It has no qualifiers.

5.15.8 SPL UNLOAD

This command unloads and cleans up the SPL$DEBUG execlet. Tracing is automatically disabled and the trace buffer deallocated. It has no qualifiers.

For more information, refer to the OpenVMS Alpha System Analysis Tools Manual.

5.16 System Services

The following table describes new and updated system services for OpenVMS Version 7.3.

For additional information, refer to the OpenVMS System Services Reference Manual.

Table 5-6 shows the TCP/IP files that contain global symbols for the VAX and Alpha SDA READ commands.

These files are only available if TCP/IP services has been installed. They are found in SYS$SYSTEM, and are not automatically read in when you issue a READ/EXEC command.

Table 5-7 shows the TCP/IP files that define global locations within the Executive Image for the VAX SDA command.

These files are only available if TCP/IP services has been installed. They are found in SYS$SYSTEM, and are not automatically read in when you issue a READ/EXEC command.

For more detailed information, refer to the OpenVMS VAX System Dump Analyzer Utility Manual and the OpenVMS Alpha System Analysis Tools Manual.

5.18 Visual Threads Version 2.1 (Alpha)

Visual Threads is a unique tool that lets you debug and analyze multithreaded applications. You can use Visual Threads to automatically diagnose common problems associated with multithreading including deadlock, mutex, and thread usage errors. Also, you can use Visual Threads to monitor the thread-related performance of an application, helping you to identify bottlenecks or locking granularity problems. Visual Threads helps you identify problem areas in an application even if the application does not show specific symptoms.

Visual Threads includes the following features:

• Collects detailed information about significant thread-related state changes ("events").
• Analyzes common threading problems automatically based on predefined rules applied to the event stream.
• Rule customization for application-specific parameters and actions.
• Automatic statistics gathering, by sampling the event stream.
• Categories of analysis: data protection errors (race conditions), deadlocks, programming errors, lock activity, performance.
• Graphical visualization of the frequency of thread-related events and thread state, snapshots of historical program state, and object-specific graphs for each collected statistic.
• Lock activity profiling to reveal where various types of lock activity are occurring in your application, including: Number of Locks, Contended Locks, Locked Time, and Wait Time. Lock activity is collected and displayed for individual locks.
• Summarizes the program run and provides reports.
• Threads Snapshot view displays the historical state of threads represented at specific times in the main thread overview graph.
• Find and Filter support in the Event Window to allow you to quickly locate particular events.
• CPU Utilization Window shows the CPU percentage used by each thread.
• Thread Transitions Window depicts each state change for a detailed view.

For more information about these features, refer to the Visual Threads product documentation, which is available on the OpenVMS Alpha CD-ROM in directory [VISUAL_THREADS_021], or by using the online Help system.