anecdotes:not_expected_to_understand_this
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| anecdotes:not_expected_to_understand_this [2016/01/12 10:31] – created wkt | anecdotes:not_expected_to_understand_this [2016/01/23 10:38] – wkt | ||
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| ===== /* You are not expected to understand this */ ===== | ===== /* You are not expected to understand this */ ===== | ||
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| + | (taken from Dennis Ritchie' | ||
| Every now and then on Usenet or elsewhere I run across a reference to a certain comment in the source code of the Sixth Edition Unix operating system. | Every now and then on Usenet or elsewhere I run across a reference to a certain comment in the source code of the Sixth Edition Unix operating system. | ||
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| It's often quoted as a slur on the quantity or quality of the comments in the Bell Labs research releases of Unix. Not an unfair observation in general, I fear, but in this case unjustified. The actual code and other commentary surrounding it were precisely this: | It's often quoted as a slur on the quantity or quality of the comments in the Bell Labs research releases of Unix. Not an unfair observation in general, I fear, but in this case unjustified. The actual code and other commentary surrounding it were precisely this: | ||
| - | < | + | < |
| + | | ||
| * Switch to stack of the new process and set up | * Switch to stack of the new process and set up | ||
| * his segmentation registers. | * his segmentation registers. | ||
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| */ | */ | ||
| if(rp-> | if(rp-> | ||
| - | rp-> | + | |
| aretu(u.u_ssav); | aretu(u.u_ssav); | ||
| } | } | ||
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| */ | */ | ||
| return(1); | return(1); | ||
| - | '' | ||
| </ | </ | ||
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| So we tried to explain what was going on. "You are not expected to understand this" was intended as a remark in the spirit of "This won't be on the exam," rather than as an impudent challenge. | So we tried to explain what was going on. "You are not expected to understand this" was intended as a remark in the spirit of "This won't be on the exam," rather than as an impudent challenge. | ||
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| So, for Steve Johnson and me, trying to move the kernel for the first time to a new machine, this code was indeed on the exam. It took about a week of agonizing before we finally convinced each other that the mechanism was wrong and no fiddling with the compiler was useful. We redid the coroutine control-passing primitives altogether, and this code section, and the comment, passed into history. | So, for Steve Johnson and me, trying to move the kernel for the first time to a new machine, this code was indeed on the exam. It took about a week of agonizing before we finally convinced each other that the mechanism was wrong and no fiddling with the compiler was useful. We redid the coroutine control-passing primitives altogether, and this code section, and the comment, passed into history. | ||
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| + | Also see [[https:// | ||
anecdotes/not_expected_to_understand_this.txt · Last modified: 2022/07/08 09:22 by 192.99.0.24