lock up

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lock up

Brit a small shop with no attached quarters for the owner or shopkeeper
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

lock up

[′läk ¦əp]
(graphic arts)
To position a form in the frame in which type and plates are locked up for letterpress printing.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


(ABnormal END) Pronounced "ab-end." An abend is an unexpected termination that causes the computer, smartphone or tablet to stop responding. The abend occurs either when the processor is presented with instructions or data it cannot recognize, or a program tries to address memory beyond a defined boundary. Abends are generally the result of erroneous software logic in the application or operating system (see anomaly).

Crash, Freeze, Lock Up and Hang
A "crash" occurs when the computer issues a "fault" and deliberately halts that line of execution. The terms "freeze," "lock up" or "hang" may refer to software that is actually still running but has erroneously wound up in an endless, internal loop that renders the program useless. In practice, the terms "crash," "freeze," "lock up" and "hang" are used synonymously. See infinite loop.

Bad Hardware Can Look Like Bad Software
A serious hardware failure will stop a computer-based device that has no redundant components. For example, a short circuit on the motherboard will halt the operation; however, a failing memory cell can cause an instruction to point to an erroneous location, making it look like a software failure.

It Depends on the OS
If the abend occurs due to a bug in an application and the operating system is not resilient, the computer locks up and has to be rebooted. Modern operating systems attempt to halt only the offending application and allow the remaining applications to continue. As operating systems evolve through the years, they are more tolerant of application bugs. However, operating systems themselves are not 100% foolproof, and bad applications can cause operating systems to crash; a major motivation for running in a virtual mode (see virtualization and virtual machine).

A Miracle It All Works
If you consider what goes on inside a computer, you might wonder why it does not crash more often. An ordinary home computer can easily have 64 billion memory (RAM) cells. Every second, millions of them switch their status between charged and uncharged (1 to 0; 0 to 1). If only one cell fails, it can cause an instruction to be invalid, and an abend can occur. See head crash, GPF, active area and transistor concept.

The green blocks are machine instructions executed by the CPU one after the other until a branch (jump) instruction breaks the sequence and points to an instruction elsewhere in the program. Abending (crashing, hanging, etc.) occurs when the program erroneously points outside of its address space, typically due to bad logic.
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References in periodicals archive ?
Earlier this year, Pincus asked a Delaware court to throw out a lawsuit that alleging that he and others had broken their duty to shareholders by waiving lockup agreements for themselves, while continuing to enforce them for the majority of investors.
Additionally, since lockup agreements only allow insider selling prior to lockup expiration if the lead underwriters agree with such early release, a lockup may assist the lead underwriter in extracting additional compensation by either making markets for the shares of insiders' block transactions or underwriting seasoned equity offerings (SEOs).
Faced with the prospect of a down economy, entering our seasonally slow summer months and working through our bankruptcy commitments to cut expenses as outlined in our lockup agreement, we must further reduce overhead.
The final element which may be used to ensure the ongoing involvement of entrepreneurs in their venture is the lockup agreement. The lockup agreement is an agreement wherein the pre-IPO shareholders in the organization promise not to sell or disperse any of their shares for a specified period of time after the IPO (Bradley, Jordan, Yi, & Roten, 2001).
Goldman Sachs is selling almost the entire stake that it is free to divest under a revised lockup agreement with ICBC.
20) ruled that deferral of income recognition under LRC section 83(c)(3) cannot be extended past the Securities Exchange Act of 1934, section 16(b)'s six-month period on the basis of a lockup agreement independently negotiated between a corporation and employee.
Energis was thrown into a dispute with one of its largest shareholders yesterday, over what the telecoms company said was the breach of a lockup agreement not to sell its stock.
Seeking the middle ground in this debate, several issuers in 1998 chose to limit the application of their rights plans so as to permit a bidder to enter a lockup agreement, provided that the party being locked-up is allowed to tender its shares to another bid that is at least 5% higher than the original bid.