hyung-hwan
46dd217591
various bug fixes in dealing with multiple instances - still more to fix more methods to dictionary access files to access cons cell to the core module
37 lines
1.1 KiB
Plaintext
37 lines
1.1 KiB
Plaintext
## sys.pipe and the non-blocking I/O contract
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fun chk(ok msg) {
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if ok { printf "OK: %s\n" msg } \
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else { printf "ERROR: %s\n" msg }
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}
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p := (sys.pipe)
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chk (array? p) "sys.pipe returns an array"
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r := (core.basicAt p 0)
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w := (core.basicAt p 1)
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chk (integer? r) "the read end is a handle id"
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chk (integer? w) "the write end is a handle id"
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chk (not (= r w)) "the two ends are distinct handles"
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buf := (core.basicNew ByteArray 16)
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## a pipe with nothing in it must report "would block" rather than stalling
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chk (= (sys.read r buf) -1) "reading an empty pipe returns -1 (would block)"
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wb := (core.basicNew ByteArray 3)
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core.basicAtPut wb 0 97
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core.basicAtPut wb 1 98
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core.basicAtPut wb 2 99
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chk (= (sys.write w wb) 3) "writing to the pipe returns the count"
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n := (sys.read r buf)
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chk (= n 3) "the data comes back"
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chk (= (core.basicAt buf 0) 97) "byte 0 correct"
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chk (= (core.basicAt buf 2) 99) "byte 2 correct"
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chk (= (sys.read r buf) -1) "the pipe is empty again"
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## closing the writer turns the next read into an end-of-file
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sys.close w
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chk (= (sys.read r buf) 0) "reading after the writer closed returns 0 (eof)"
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sys.close r
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