Sun Microsystems 2 manual Maximum number of tasks isolates allowed

Page 38

Each resource typically has five constants that define the policy. A pair of constants defines the reservation and the limit for each MIDlet suite. These constants have the suffixes SUITE_RESERVED and SUITE_LIMIT, respectively. Another pair of constants defines the reservation and limit for the AMS task. These constants have the suffixes AMS_RESERVED and AMS_LIMIT. Finally, the fifth constant specifies the global limit for the entire system. The sum of all allocations by all MIDlet suites and the AMS cannot exceed this limit. This constant has the suffix GLOBAL_LIMIT.

For certain resources, it is important to choose the AMS reservation carefully. For example, the AMS needs to open various MIDlet files in order to change application settings. If the AMS open file reservation is not set high enough, and running MIDlets have consumed all available file handles, the normal operation of the AMS will be disrupted.

TABLE 3-1Constant Definitions for the Resource Management Policy

Name

Description

 

 

MAX_ISOLATES

Maximum number of tasks (isolates) allowed.

SUITE_MEMORY_RESERVED

Heap memory reserved for each MIDlet suite, in

 

kilobytes

SUITE_MEMORY_LIMIT

Heap memory limit for each MIDlet suite, in

 

kilobytes

TCP_CLI_GLOBAL_LIMIT

TCP client socket limit for the entire system

TCP_CLI_AMS_RESERVED

TCP client socket reservation for the AMS

TCP_CLI_AMS_LIMIT

TCP client socket limit for the AMS

TCP_CLI_SUITE_RESERVED

TCP client socket reservation for each MIDlet suite

TCP_CLI_SUITE_LIMIT

TCP client socket limit for each MIDlet suite

 

 

Five constants determine the policy for TCP client sockets: the global limit, the reservation and limit for the AMS, and the reservation and limit for each MIDlet suite. This pattern of five constants is repeated for several different resources, including the following:

TCP server sockets

UDP datagram sockets

Open file handles

Audio channels

Mutable images

Immutable images

For each of these resource types, you can specify independently the global limit and the reservations and limits for the AMS and for each MIDlet suite.

26 Multitasking Guide • May 2007

Image 38
Contents Multitasking Guide Page Contents Glossary Index Code Samples Vi Multitasking Guide May Tables Viii Multitasking Guide May Preface Before You Read This GuideHow This Guide Is Organized Related DocumentationTypographic Conventions Used in This Guide AaBbCc123Accessing Sun Documentation Online Sun Welcomes Your CommentsIntroduction Multitasking Robustness Mechanisms Compared With PoliciesMultitasking Guide May Multitasking Safety Multitask Safety and Multithread Safety Global and Static Data Singletons Multitasking Safety Example Code Example 2-1Native API for a Microwave OvenTypical usage of this API is shown in Code Example Multithread Safety Code Example 2-5Using the Locking Mechanism Multitask Safety Code Example 2-7Migrating Initialization to Native Code Establishing Per-Task Context Code Example 2-8Keeping State in Java Code Code Example 2-9Implementing the Native ncook Method Kniexport Knireturntypeint Multitasking Safety Multitasking Guide May Managing Native Resources Resource Management Mechanisms ReservationLimit Default Resource Allocation Policies RevocationCustomization of Resource Allocation Policies Maximum number of tasks isolates allowed Managing Native Resources Multitasking Guide May Other Multitasking Issues Switching the Foreground MIDletAlternative Policies and Their Implementations Default PolicyScheduling the CPU Default CPU Scheduling Policy Default User Notification Policies Interrupting the UserGlossary Java Community ProcessTM Jcptm Glossary Sun Java Device Test Index Multitasking Guide May
Related manuals
Manual 58 pages 34.88 Kb

2 specifications

Sun Microsystems, founded in 1982, was a significant player in the computing industry, best known for its innovative technology solutions and workstations, particularly the Sun-4, which represented a key milestone in the company's history. The Sun-4 architecture, launched in 1987, utilized the SPARC (Scalable Processor Architecture) RISC processor, notable for its high performance and scalability.

One of the primary features of Sun Microsystems' platforms was their ability to efficiently handle multitasking and resource management, making them ideal for enterprise-level applications and development environments. Sun-4 workstations boasted impressive graphics capabilities with the addition of advanced graphical user interfaces, support for color displays, and the SUNVIEW windowing system, which enhanced user experience and productivity.

The Sun-4 systems also supported the SunOS operating system, which was based on UNIX. This operating system was engineered for stability and robustness, offering features like multiuser support, networked environments, and advanced security options. Moreover, SunOS provided seamless integration with various programming languages, including C and C++, facilitating software development that aligned with industry standards.

Another standout characteristic of Sun Microsystems was its commitment to open systems and standards. By providing developers with comprehensive tools and environments, such as the Standardized Application Programming Interface (API) and support for networking protocols, Sun facilitated interoperability among different computing platforms. The emphasis on open architecture also meant that customers could easily upgrade their systems without being locked into proprietary solutions.

Sun Microsystems was also ahead of its time with innovations in network computing. Their workstations were among the first to support network file systems and distributed computing concepts, enabling seamless data sharing across multiple systems. With the introduction of the Network File System (NFS), Sun revolutionized how data was accessed and managed across networks, which played a significant role in the evolving landscape of client-server computing.

In summary, the Sun Microsystems 2 and its successive innovations in workstation technology highlighted the company's forward-thinking approach. By integrating powerful performance with open systems, robust operating systems, and advanced networking capabilities, Sun laid the groundwork for modern computing, influencing various sectors from academia to enterprise solutions. Even after its acquisition by Oracle in 2010, the legacy of Sun Microsystems continues to be felt across the computing industry.