Allow program to contain comments (semicolon in first column.)
Chris Pressey
10 years ago
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which they write to and read from is shared between them.
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It then computes all possible interleavings of these two programs, and
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executes them all. Unless _all_ the interleavings leave the memory in exactly
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the same state after execution, the programs have a race condition.
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executes them all, each on a freshly-zeroed shared memory. Unless _all_
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the interleavings leave the memory in exactly the same state after execution,
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the programs have a race condition.
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Example
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-------
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These two programs do not have a race condition. The reason is that
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Matchbox's `INC` instruction atomically updates memory; two `INC`s cannot
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run at the same time.
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PROG 0
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INC M0
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PROG 1
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INC M1
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But the following two programs _do_ have a race condition:
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PROG 0
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MOV M0, R0
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INC R0
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MOV R0, M0
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PROG 1
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MOV M0, R0
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INC R0
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MOV R0, M0
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The reason is that the second program's `MOV M0, R0` might happen before
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the first program's `MOV R0, M0` — in which case M0 = 1 at the end — or it
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might happen after — in which case M0 = 2.
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TODO
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----
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* discard impossible run traces (once we have WAIT)
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* ability to break on first inconsistent result (for long programs)
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* more instructions
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* allow comments in programs
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* better error handling
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* load both programs from single source file
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* write a few words about atomic operations
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* implement some of those classic race-condition-free algorithms w/o
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var lines = str.split("\n");
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this.code = [];
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for (var i = 0; i < lines.length; i++) {
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if (!lines[i] || lines[i].charAt(0) === ';') continue;
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var instr = (new Instruction()).init({
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'reg': reg
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});
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if (!lines[i]) continue;
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if (instr.parse(lines[i])) {
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this.code.push(instr);
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} else {
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