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#ifdef __APPLE__
#include <sys/event.h>
#include <mach/mach.h>
// errno
#include <errno.h>
extern "C" mach_port_t io_darwin_create_machport(uint64_t wakeup, int32_t fd,
void *wakeup_buffer_,
size_t nbytes) {
mach_port_t port;
// Create a Mach port that will be used to wake up the pump
kern_return_t kr =
mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &port);
if (kr != KERN_SUCCESS) {
return 0;
}
// Configure the event to directly receive the Mach message as part of the
// kevent64() call.
kevent64_s event{};
event.ident = port;
event.filter = EVFILT_MACHPORT;
event.flags = EV_ADD | EV_ENABLE;
event.fflags = MACH_RCV_MSG | MACH_RCV_OVERWRITE;
event.ext[0] = reinterpret_cast<uint64_t>(wakeup_buffer_);
event.ext[1] = nbytes;
while (true) {
int rv = kevent64(fd, &event, 1, NULL, 0, 0, NULL);
if (rv == -1) {
if (errno == EINTR) {
continue;
}
return 0;
}
return port;
}
}
extern "C" bool io_darwin_schedule_wakeup(mach_port_t waker) {
mach_msg_empty_send_t message{};
message.header.msgh_size = sizeof(message);
message.header.msgh_bits =
MACH_MSGH_BITS_REMOTE(MACH_MSG_TYPE_MAKE_SEND_ONCE);
message.header.msgh_remote_port = waker;
kern_return_t kr = mach_msg_send(&message.header);
if (kr != KERN_SUCCESS) {
// If io_darwin_schedule_wakeup() is being called by other threads faster
// than the pump can dispatch work, the kernel message queue for the wakeup
// port can fill The kernel does return a SEND_ONCE right in the case of
// failure, which must be destroyed to avoid leaking.
mach_msg_destroy(&message.header);
return false;
}
return true;
}
#else
// stub out these symbols
extern "C" int io_darwin_create_machport(unsigned long long wakeup, int fd,
void *wakeup_buffer_,
unsigned long long nbytes) {
return 0;
}
// stub out these symbols
extern "C" bool io_darwin_schedule_wakeup(void *waker) { return false; }
#endif
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