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Don't use timerfd for epollWaitTimeboxed()
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@njhill
njhill committed Sep 20, 2019
1 parent 3527c9a commit 8523b5a
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Showing 3 changed files with 27 additions and 45 deletions.
57 changes: 16 additions & 41 deletions transport-native-epoll/src/main/c/netty_epoll_native.c
View file
Expand Up @@ -197,9 +197,8 @@ static void netty_epoll_native_timerFdSetTime(JNIEnv* env, jclass clazz, jint ti
}
}

static jint netty_epoll_native_epollWaitNoTimeout(JNIEnv* env, jclass clazz, jint efd, jlong address, jint len, jboolean immediatePoll) {
static jint netty_epoll_native_epollWait(JNIEnv* env, jclass clazz, jint efd, jlong address, jint len, jint timeout) {
struct epoll_event *ev = (struct epoll_event*) (intptr_t) address;
const int timeout = immediatePoll ? 0 : -1;
int result, err;

do {
Expand All @@ -213,47 +212,23 @@ static jint netty_epoll_native_epollWaitNoTimeout(JNIEnv* env, jclass clazz, jin

// This method is deprecated!
static jint netty_epoll_native_epollWait0(JNIEnv* env, jclass clazz, jint efd, jlong address, jint len, jint timerFd, jint tvSec, jint tvNsec) {
struct epoll_event *ev = (struct epoll_event*) (intptr_t) address;
int result, err;

if (tvSec == 0 && tvNsec == 0) {
// Zeros = poll (aka return immediately).
do {
result = epoll_wait(efd, ev, len, 0);
if (result >= 0) {
return result;
}
} while((err = errno) == EINTR);
} else {
// only reschedule the timer if there is a newer event.
// -1 is a special value used by EpollEventLoop.
if (tvSec != ((jint) -1) && tvNsec != ((jint) -1)) {
struct itimerspec ts;
memset(&ts.it_interval, 0, sizeof(struct timespec));
ts.it_value.tv_sec = tvSec;
ts.it_value.tv_nsec = tvNsec;
if (timerfd_settime(timerFd, 0, &ts, NULL) < 0) {
netty_unix_errors_throwChannelExceptionErrorNo(env, "timerfd_settime() failed: ", errno);
return -1;
}
}
do {
result = epoll_wait(efd, ev, len, -1);
if (result > 0) {
// Detect timeout, and preserve the epoll_wait API.
if (result == 1 && ev[0].data.fd == timerFd) {
// We assume that timerFD is in ET mode. So we must consume this event to ensure we are notified
// of future timer events because ET mode only notifies a single time until the event is consumed.
uint64_t timerFireCount;
// We don't care what the result is. We just want to consume the wakeup event and reset ET.
result = read(timerFd, &timerFireCount, sizeof(uint64_t));
return 0;
}
return result;
}
} while((err = errno) == EINTR);
return netty_epoll_native_epollWait(env, clazz, efd, address, len, 0);
}
return -err;
// only reschedule the timer if there is a newer event.
// -1 is a special value used by EpollEventLoop.
if (tvSec != ((jint) -1) && tvNsec != ((jint) -1)) {
struct itimerspec ts;
memset(&ts.it_interval, 0, sizeof(struct timespec));
ts.it_value.tv_sec = tvSec;
ts.it_value.tv_nsec = tvNsec;
if (timerfd_settime(timerFd, 0, &ts, NULL) < 0) {
netty_unix_errors_throwChannelExceptionErrorNo(env, "timerfd_settime() failed: ", errno);
return -1;
}
}
return netty_epoll_native_epollWait(env, clazz, efd, address, len, -1);
}

static inline void cpu_relax() {
Expand Down Expand Up @@ -524,7 +499,7 @@ static const JNINativeMethod fixed_method_table[] = {
{ "timerFdSetTime", "(III)V", (void *) netty_epoll_native_timerFdSetTime },
{ "epollCreate", "()I", (void *) netty_epoll_native_epollCreate },
{ "epollWait0", "(IJIIII)I", (void *) netty_epoll_native_epollWait0 }, // This method is deprecated!
{ "epollWaitNoTimeout", "(IJIZ)I", (void *) netty_epoll_native_epollWaitNoTimeout },
{ "epollWait", "(IJII)I", (void *) netty_epoll_native_epollWait },
{ "epollBusyWait0", "(IJI)I", (void *) netty_epoll_native_epollBusyWait0 },
{ "epollCtlAdd0", "(III)I", (void *) netty_epoll_native_epollCtlAdd0 },
{ "epollCtlMod0", "(III)I", (void *) netty_epoll_native_epollCtlMod0 },
Expand Down
4 changes: 2 additions & 2 deletions transport-native-epoll/src/main/java/io/netty/channel/epoll/EpollEventLoop.java
View file
Expand Up @@ -305,7 +305,7 @@ private int epollWait() throws IOException {
}

private int epollWaitNow() throws IOException {
return Native.epollWait(epollFd, events, timerFd, 0, 0);
return Native.epollWait(epollFd, events, true);
}

private int epollBusyWait() throws IOException {
Expand All @@ -314,7 +314,7 @@ private int epollBusyWait() throws IOException {

private int epollWaitTimeboxed() throws IOException {
// Wait with 1 second "safeguard" timeout
return Native.epollWait(epollFd, events, timerFd, 1, 0);
return Native.epollWait(epollFd, events, 1000);
}

@Override
Expand Down
11 changes: 9 additions & 2 deletions transport-native-epoll/src/main/java/io/netty/channel/epoll/Native.java
View file
Expand Up @@ -107,7 +107,14 @@ public static int epollWait(FileDescriptor epollFd, EpollEventArray events, File
}

static int epollWait(FileDescriptor epollFd, EpollEventArray events, boolean immediatePoll) throws IOException {
int ready = epollWaitNoTimeout(epollFd.intValue(), events.memoryAddress(), events.length(), immediatePoll);
return epollWait(epollFd, events, immediatePoll ? 0 : -1);
}

/**
* This uses epoll's own timeout and does not reset/re-arm any timerfd
*/
static int epollWait(FileDescriptor epollFd, EpollEventArray events, int timeoutMillis) throws IOException {
int ready = epollWait(epollFd.intValue(), events.memoryAddress(), events.length(), timeoutMillis);
if (ready < 0) {
throw newIOException("epoll_wait", ready);
}
Expand All @@ -128,7 +135,7 @@ public static int epollBusyWait(FileDescriptor epollFd, EpollEventArray events)
}

private static native int epollWait0(int efd, long address, int len, int timerFd, int timeoutSec, int timeoutNs);
private static native int epollWaitNoTimeout(int efd, long address, int len, boolean immediatePoll);
private static native int epollWait(int efd, long address, int len, int timeout);
private static native int epollBusyWait0(int efd, long address, int len);

public static void epollCtlAdd(int efd, final int fd, final int flags) throws IOException {
Expand Down

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