Level Triggered : The process "looks" at some data-structure/state and if it matches something, notifies the interested processes i.e. set some flag somewhere etc.e.g. time 0: no packets, time 1: packet, time 2: packet will cause only 2 level-triggers at time 1 and time 2.
Edge Triggered: The process "looks"at some data-structure/state and sees if it has "changed" from the last time the process looked at it. If it has, notify other interested processes i.e. set some flag somewhere. e.g. time 0: no packets, time 1: packet, time 2: packet will cause only 1 edge-trigger at time 1.
Note here that "time" here means at the abstraction-level of "Software systems" i.e. the time a process "looks" at some data-structure. (i.e. the number of times a CPU instruction touched some abstraction (which is stored in memory (though the process may refer different memory locations at different instants))
I will describe how it works in the context of an edge-triggered vs a level-triggered epoll system call soon. The idea is that an edge-trigger is triggered once , which allows us to do reads etc in the context of a different thread without having to to fd_clr etc. Coming soon :-)
Ref: [1][2]
Edge Triggered: The process "looks"at some data-structure/state and sees if it has "changed" from the last time the process looked at it. If it has, notify other interested processes i.e. set some flag somewhere. e.g. time 0: no packets, time 1: packet, time 2: packet will cause only 1 edge-trigger at time 1.
Note here that "time" here means at the abstraction-level of "Software systems" i.e. the time a process "looks" at some data-structure. (i.e. the number of times a CPU instruction touched some abstraction (which is stored in memory (though the process may refer different memory locations at different instants))
I will describe how it works in the context of an edge-triggered vs a level-triggered epoll system call soon. The idea is that an edge-trigger is triggered once , which allows us to do reads etc in the context of a different thread without having to to fd_clr etc. Coming soon :-)
Ref: [1][2]
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