forked from lix-project/lix
9fc8d00d74
It appears that on current macOS versions, our use of poll() to detect client disconnects no longer works. As a workaround, poll() for POLLRDNORM, since this *will* wake up when the client has disconnected. The downside is that it also wakes up when input is available. So just sleep for a bit in that case. This means that on macOS, a client disconnect may take up to a second to be detected, but that's better than not being detected at all. Fixes #7584.
70 lines
1.8 KiB
C++
70 lines
1.8 KiB
C++
#pragma once
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#include <thread>
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#include <atomic>
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#include <cstdlib>
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#include <poll.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <signal.h>
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namespace nix {
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class MonitorFdHup
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{
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private:
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std::thread thread;
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public:
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MonitorFdHup(int fd)
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{
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thread = std::thread([fd]() {
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while (true) {
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/* Wait indefinitely until a POLLHUP occurs. */
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struct pollfd fds[1];
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fds[0].fd = fd;
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/* Polling for no specific events (i.e. just waiting
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for an error/hangup) doesn't work on macOS
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anymore. So wait for read events and ignore
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them. */
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fds[0].events =
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#ifdef __APPLE__
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POLLRDNORM
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#else
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0
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#endif
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;
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auto count = poll(fds, 1, -1);
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if (count == -1) abort(); // can't happen
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/* This shouldn't happen, but can on macOS due to a bug.
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See rdar://37550628.
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This may eventually need a delay or further
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coordination with the main thread if spinning proves
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too harmful.
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*/
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if (count == 0) continue;
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if (fds[0].revents & POLLHUP) {
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triggerInterrupt();
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break;
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}
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/* This will only happen on macOS. We sleep a bit to
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avoid waking up too often if the client is sending
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input. */
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sleep(1);
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}
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});
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};
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~MonitorFdHup()
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{
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pthread_cancel(thread.native_handle());
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thread.join();
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}
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};
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}
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