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Merge pull request #1872 from shlevy/macOS-poll-fix

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monitor-fds: Fix on macOS.
This commit is contained in:
Eelco Dolstra 2018-02-15 11:43:56 +01:00 committed by GitHub
parent 96d48318cb ac973a6d3c
commit d26b71fda6
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GPG key ID: 4AEE18F83AFDEB23
1 changed files with 23 additions and 7 deletions
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30
src/libutil/monitor-fd.hh
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@ -21,13 +21,29 @@ public:
MonitorFdHup(int fd)
{
thread = std::thread([fd]() {
/* Wait indefinitely until a POLLHUP occurs. */
struct pollfd fds[1];
fds[0].fd = fd;
fds[0].events = 0;
if (poll(fds, 1, -1) == -1) abort(); // can't happen
assert(fds[0].revents & POLLHUP);
triggerInterrupt();
while (true) {
/* Wait indefinitely until a POLLHUP occurs. */
struct pollfd fds[1];
fds[0].fd = fd;
/* This shouldn't be necessary, but macOS doesn't seem to
like a zeroed out events field.
See rdar://37537852.
*/
fds[0].events = POLLHUP;
auto count = poll(fds, 1, -1);
if (count == -1) abort(); // can't happen
/* This shouldn't happen, but can on macOS due to a bug.
See rdar://37550628.
This may eventually need a delay or further
coordination with the main thread if spinning proves
too harmful.
*/
if (count == 0) continue;
assert(fds[0].revents & POLLHUP);
triggerInterrupt();
break;
}
});
};