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gps read optimization

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This commit is contained in:
Artem Sabadyr 2016-09-28 15:02:46 +03:00 committed by Lorenz Meier
parent fe40e9cfae
commit 4c04b7bb53
1 changed files with 8 additions and 1 deletions
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9
src/drivers/gps/gps.cpp
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@ -399,9 +399,16 @@ int GPS::pollOrRead(uint8_t *buf, size_t buf_length, int timeout)
* We are here because poll says there is some data, so this
* won't block even on a blocking device. But don't read immediately
* by 1-2 bytes, wait for some more data to save expensive read() calls.
* If we have all requested data available, read it without waiting.
* If more bytes are available, we'll go back to poll() again.
*/
usleep(GPS_WAIT_BEFORE_READ * 1000);
int err = 0, bytesAvailable = 0;
err = ioctl(_serial_fd, FIONREAD, (unsigned long)&bytesAvailable);
if ((err != 0) || (bytesAvailable < buf_length)) {
usleep(GPS_WAIT_BEFORE_READ * 1000);
}
ret = ::read(_serial_fd, buf, buf_length);
} else {