November 8th, 2005

Why was GlobalWire called GlobalWire?

John Elliott wondered why the GlobalWire function was called GlobalWire.

First, some background for those who never had to write 16-bit Windows programs. The GlobalWire function was similar to the 16-bit GlobalLock function, except that it had the bonus feature of relocating the memory to the lowest available linear address. You used this function as a courtesy if you intended to leave the memory locked for a long time. Moving it to the edge of the address space means that it is unlikely to become an obstacle in the middle of the address space which would otherwise prevent future large memory allocations from succeeding.

But why “wire”?

This employs a colloquial sense of the word “wire” as a verb which has lost its currency in the intervening years. To wire means to fasten securely in a very strong sense. It probably derives from the phrase “hard-wired”, which means “permanently attached in circuitry”. Therefore, “wiring” memory into place ensures that it doesn’t move around.

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Raymond has been involved in the evolution of Windows for more than 30 years. In 2003, he began a Web site known as The Old New Thing which has grown in popularity far beyond his wildest imagination, a development which still gives him the heebie-jeebies. The Web site spawned a book, coincidentally also titled The Old New Thing (Addison Wesley 2007). He occasionally appears on the Windows Dev Docs Twitter account to tell stories which convey no useful information.

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