润土
少年充满激情
中年麻木、颓废
还是要充满激情
Discussion
少年时期，熬夜…
Fetch
Decode
Execute
Write little C program and look into corresponding Assembly program
Learn from short C to understand Assembly
RTOS : software that manages the **time** and **resources** of a CPU
ISR (Interrupt Service Routines) is a hardware feature, has nothing to do with the RTOS
An interrupt is a hardware mechanism used to inform the CPU that an asynchronous event has occurred
Interrupt : is a signal to the processor indicating an event that needs immediate attention
Micrium OS interrupt handlers (ISRs) take over when interrupts occur
The ISR saves CPU registers and calls OSIntEnter() and OSIntExit()
After the ISR, the scheduler decides which takes to run
Micrium OS has a built-in ISR : the kernel’s tick handler
ISR is provided by Micrium OS to handle interrupt from outside hardware
Semaphores have two basic operations
Pend : wait for event
Post : signal occurrence of event
Pend Operation
Decrements counter and executed waiting task
Or else moves ready task into waiting state
——————————————————
Post Operation
Increments counter to signal occurrence of an event
Or else moves waiting task into ready state
Semaphores are used to synchronize tasks
Semaphores use a counter to track the number of events
Posting a semaphore notifies a task about an event
A semaphore pend allows a task to wait on an event
Potential problem of semaphore is priority invertion
Low priority task holds some resources which are needed by high priority task.
1. Low priority task is running and holding the key resource which is also needed by high priority task (high priority is in waiting state for an event to occur and another condition to run the high priority task is to have the key resource which is now holding by the low priority)
2. ISR occurs and the event needed by the high priority task is coming in. The high priority task begins to run, but the key resource is holding by low priority. Then high priority task releases the CPU control.
3. The OS scheduler finds a middle priority task in ready tasks list and give CPU control to middle priority task
4. Middle priority task completes and low priority task continues to run (since high priority task still waiting for the key resource which is still held by low priority task)
5. Low priority task finishes and releases the key resource. High priority task begins to run
This is priority inversion
Code + Data
Vim
Neovim Neovim-qt Neovide
Kakoune
Helix
浙江台州
高中数理化好（不想上，爱钱）
老师讲普通话，听不懂，换了一个讲当地话的学校
照相（100去买上海，被偷）（80去买了个苏州虎丘的照相机）
照相的冲洗液中含银，分解金银铜（大家都做，就退出）
电冰箱配件（胶水）
电冰箱
6.4
上大学三年
建材（银色外墙）（大家都做，就退出）
摩托车（踏板）
造车（桑塔拉）（福特，阿斯顿马丁，8个亿美金，单独剥离没那个能力，捷豹路虎，13个亿美金）（看好沃尔沃，完善的体系，找一个老师、伙伴，但是研究沃尔沃，2000年看上沃尔沃，中国加入世贸组织，觉得自己摸索慢，2000年要收购沃尔沃，内部觉得他痴人说梦）
时代推动
工匠精神
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#泰国队员想来中国队吃豆角焖面#
泰国乒乓球运动员吐槽巴黎太热，想来中国队宿舍凉快一下，吃个豆角焖面[嘻嘻]。（视频来源: dy 泰国女生瑾妮帕）
#泰国队员想来中国队宿舍凉快# | #巴黎奥运会 空调# http://t.cn/A68LWg9Y
2024/07/22
大汗 冷水澡 吹空调
体温37.6～38.6波动
全身发热
怕冷
裹被子
吹空调
出汗
长衣长裤
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嗓子微痛
发热
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吞咽疼
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扁桃体发炎
早：阿莫西林
8小时2
冷敷
擦拭
2024/07/26
扁桃体发炎缓解
轻微咳嗽
冷敷法
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咳嗽缓解
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晚：爽