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Bugfix: libeio race condition

Process at most 10 pending responses from the thread pool in one go.
10 was chosen arbitrarily.
Test and report by Felix Geisendörfer <felix@debuggable.com>
v0.7.4-release
Ryan Dahl 15 years ago
parent
commit
0d7e88a429
  1. 3
      src/node.cc
  2. 63
      test/mjsunit/test-eio-race.js

3
src/node.cc

@ -949,6 +949,9 @@ int main(int argc, char *argv[]) {
ev_async_init(&node::eio_watcher, node::EIOCallback);
// 2. Actaully start the thread pool.
eio_init(node::EIOWantPoll, NULL);
// Don't handle more than 10 reqs on each eio_poll(). This is to avoid
// race conditions. See test/mjsunit/test-eio-race.js
eio_set_max_poll_reqs(10);
// 3. Start watcher.
ev_async_start(EV_DEFAULT_UC_ &node::eio_watcher);
// 4. Remove a reference to the async watcher. This means we'll drop out

63
test/mjsunit/test-eio-race.js

@ -0,0 +1,63 @@
process.mixin(require("./common"));
var
count = 100,
posix = require('posix');
function tryToKillEventLoop() {
puts('trying to kill event loop ...');
posix.stat(__filename)
.addCallback(function() {
puts('first posix.stat succeeded ...');
posix.stat(__filename)
.addCallback(function() {
puts('second posix.stat succeeded ...');
puts('could not kill event loop, retrying...');
setTimeout(function () {
if (--count) {
tryToKillEventLoop();
} else {
process.exit(0);
}
}, 1);
})
.addErrback(function() {
throw new Exception('second posix.stat failed')
})
})
.addErrback(function() {
throw new Exception('first posix.stat failed')
});
}
// Generate a lot of thread pool events
var pos = 0;
posix.open('/dev/zero', process.O_RDONLY, 0666).addCallback(function (rd) {
function readChunk () {
posix.read(rd, 1024, pos, 'binary').addCallback(function (chunk, bytesRead) {
if (chunk) {
pos += bytesRead;
//puts(pos);
readChunk();
} else {
posix.close(rd);
throw new Exception(BIG_FILE+' should not end before the issue shows up');
}
}).addErrback(function () {
throw new Exception('could not read from '+BIG_FILE);
});
}
readChunk();
}).addErrback(function () {
throw new Exception('could not open '+BIG_FILE);
});
tryToKillEventLoop();
process.addListener("exit", function () {
assert.ok(pos > 10000);
});
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