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Two way sync assertion

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Nicholas Kariniemi 2015-11-30 00:29:02 +02:00
parent 20c408e491
commit 0ea9aab101
1 changed files with 13 additions and 7 deletions
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18
csp/sync.csp
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@ -10,7 +10,7 @@ channel up:CLIENTS.TIMES
channel down:CLIENTS.TIMES.TIMES channel down:CLIENTS.TIMES.TIMES
channel bufdown:CLIENTS.TIMES.TIMES channel bufdown:CLIENTS.TIMES.TIMES
channel saved:CLIENTS.TIMES channel saved:CLIENTS.TIMES
channel bufsaved:CLIENTS.TIMES channel report_queue:CLIENTS.TIMES
next_t(t) = (t + 1) % NUM_DB_STATES next_t(t) = (t + 1) % NUM_DB_STATES
@ -33,21 +33,21 @@ SERVER(i, client_t) =
-> saved!i?new_server_t -> saved!i?new_server_t
-> down!i!server_t!new_server_t -> down!i!server_t!new_server_t
-> SERVER(i, new_server_t) -> SERVER(i, new_server_t)
[] bufsaved?j:diff(CLIENTS,{i})?new_server_t [] report_queue?j:diff(CLIENTS,{i})?new_server_t
-> if new_server_t == client_t -> if new_server_t == client_t
then SERVER(i, client_t) then SERVER(i, client_t)
else down!i!client_t!new_server_t else down!i!client_t!new_server_t
-> SERVER(i, new_server_t) -> SERVER(i, new_server_t)
SAVEDBUF(i) = saved?j:diff(CLIENTS,{i})?t -> SAVEDBUF'(i, j, t) REPORTQUEUE(i) = saved?j:diff(CLIENTS,{i})?t -> REPORTQUEUE'(i, j, t)
SAVEDBUF'(i, j, t) = saved?j':diff(CLIENTS,{i})?new_t -> SAVEDBUF'(i, j', new_t) REPORTQUEUE'(i, j, t) = saved?j':diff(CLIENTS,{i})?new_t -> REPORTQUEUE'(i, j', new_t)
[] bufsaved!j!t -> SAVEDBUF(i) [] report_queue!j!t -> REPORTQUEUE(i)
DB(t) = save?i DB(t) = save?i
-> saved!i!next_t(t) -> saved!i!next_t(t)
-> DB(next_t(t)) -> DB(next_t(t))
CONN(i, t0) = (CLIENT(i, t0) [|{| bufdown.i |}|] DOWNBUF(i)) [|{| up.i, down.i |}|] (SERVER(i, t0) [|{| bufsaved |}|] SAVEDBUF(i)) CONN(i, t0) = (CLIENT(i, t0) [|{| bufdown.i |}|] DOWNBUF(i)) [|{| up.i, down.i |}|] (SERVER(i, t0) [|{| report_queue |}|] REPORTQUEUE(i))
SYSTEM = (CONN(0,0) [|{| save.0, saved |}|] DB(0)) [|{| save.1, saved |}|] CONN(1,0) SYSTEM = (CONN(0,0) [|{| save.0, saved |}|] DB(0)) [|{| save.1, saved |}|] CONN(1,0)
@ -108,3 +108,9 @@ TwoWaySync = input.0 -> input.1 -> ((render.0.2 -> render.1.2 -> STOP) |~|
(render.1.2 -> render.0.2 -> STOP)) (render.1.2 -> render.0.2 -> STOP))
assert TwoWaySync [FD= (SYSTEM [|{| input |}|] AlternateInputs) \diff(Events, {input.0, input.1, render.0.2, render.1.2}) assert TwoWaySync [FD= (SYSTEM [|{| input |}|] AlternateInputs) \diff(Events, {input.0, input.1, render.0.2, render.1.2})
-- Issue: our system is (no longer) free of deadlock, probably because of buffer changes. Yup. Basically the same deadlock problem exists here as without the buffer, it just means you have to fill up the buffer first.
-- Really our server should know to send down one event at a time. It might be that it actually will only work this way anyway, as the original file says only one item can be in transit at a time. So what if we rework to make this true?
-- The server then would not take in buffered report queue events until the client "acked" the previous
-- Is this deadlock ACTUALLY a problem? The real underlying istuation is that server and client don't have to sync on events, both can send both ways asynchronously. But we pretend that they sync on these.