"A task is an independent thread of execution that contains a sequence of independently schedulable instructions. Some kernels provide another type of a schedulable object called a process. Processes are similar to tasks in that they can independently compete for CPU execution time. Processes differ from tasks in that they provide better memory protection features, at the expense of performance and memory overhead. Despite these differences, for the sake of simplicity, this book uses task to mean either a task or a process. "
任務是一個包含了一系列獨立的調度指令的獨立線程.一些內核提供另外一種被稱作進程的調度對象.進程跟任務的相似點是它們能夠獨立地佔用CPU執行時間.不同點是進程提供更好的內存保護功能,從而性能和內存的開銷增大.儘管有這些不同,從簡單化方面考慮,本書用"任務"這個詞來表示任務或是進程.
看原版書也有兩本了,第一本是<<A Book on C:Programming in C,Fourth Edition >>,第二本是<<An Embedded Software Primer >>,最初是懷着崇敬的心情看的,感覺還行,都能看懂,畢竟當時C語言學完了,所以A Book on C看着不怎麼費勁,<<An Embedded Software Primer >>是我一口氣讀完的,花了大概六個星期,很爽的感覺.老外寫書很講究藝術,讀起來是一種享受,有一種悟道的感覺.
文字只不過是思想的載體
換一種文字來獲取新的思想真的是非常神奇
一種只可意會而無法言傳的美妙
思想依附於文字
卻又超脫於文字
