Mirrors/overte
3
0
Fork 0
mirror of https://github.com/overte-org/overte.git synced 2025-04-15 04:07:23 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

Improve perf of Win32 usleep

Browse source
This commit is contained in:
Zach Pomerantz 2016-05-03 16:25:09 -07:00
parent 3619821b82
commit 526143b097
1 changed files with 21 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

32
libraries/shared/src/SharedUtil.cpp
View file

@ -455,19 +455,29 @@ void printVoxelCode(unsigned char* voxelCode) {
}
#ifdef _WIN32
void usleep(int waitTime) {
const quint64 BUSY_LOOP_USECS = 2000;
quint64 compTime = waitTime + usecTimestampNow();
quint64 compTimeSleep = compTime - BUSY_LOOP_USECS;
while (true) {
if (usecTimestampNow() < compTimeSleep) {
QThread::msleep(1);
}
if (usecTimestampNow() >= compTime) {
break;
}
void usleep(int waitTime) {
quint64 sleepUntil = waitTime + usecTimestampNow();
// Busy wait with sleep/yield where possible
while (true) {
quint64 now = usecTimestampNow();
if (now >= sleepUntil) {
break;
}
// Sleep if we have at least 1ms to spare
const int MIN_SLEEP_USECS = 1000;
// msleep is allowed to overshoot, so give it a 100us berth
const int MIN_SLEEP_USECS_BERTH = 100;
if (sleepUntil - now > (MIN_SLEEP_USECS + MIN_SLEEP_USECS_BERTH)) {
unsigned long sleepFor = (sleepUntil - now - MIN_SLEEP_USECS_BERTH) / USECS_PER_MSEC;
QThread::msleep(sleepFor);
// Yield otherwise
} else {
QThread::yieldCurrentThread();
}
}
}
#endif
// Inserts the value and key into three arrays sorted by the key array, the first array is the value,