这是6.0之前的poll模型。
solaris\native\sun\nio\ch\SocketChannelImpl.c
JNIEXPORT jint JNICALL
Java_sun_nio_ch_SocketChannelImpl_checkConnect(JNIEnv *env, jobject this,
jobject fdo, jboolean block,
jboolean ready)
{
int error = 0;
int n = sizeof(int);
jint fd = fdval(env, fdo);
int result = 0;
struct pollfd poller;
poller.revents = 1;
if (!ready) {
poller.fd = fd;
poller.events = POLLOUT;
poller.revents = 0;
result = poll(&poller, 1, block ? -1 : 0);
if (result < 0) {
JNU_ThrowIOExceptionWithLastError(env, "Poll failed");
return IOS_THROWN;
}
if (!block && (result == 0))
return IOS_UNAVAILABLE;
}
if (poller.revents) {
errno = 0;
result = getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &n);
if (result < 0) {
handleSocketError(env, errno);
return JNI_FALSE;
} else if (error) {
handleSocketError(env, error);
return JNI_FALSE;
}
return 1;
}
return 0;
}
6.0缺省的模型是使用epoll
E:\Java\jdk-6-rc-src\j2se\src\solaris\native\sun\nio\ch\EPollArrayWrapper.c
JNIEXPORT void JNICALL
Java_sun_nio_ch_EPollArrayWrapper_init(JNIEnv *env, jclass this)
{
epoll_create_func = (epoll_create_t) dlsym(RTLD_DEFAULT, "epoll_create");
epoll_ctl_func = (epoll_ctl_t) dlsym(RTLD_DEFAULT, "epoll_ctl");
epoll_wait_func = (epoll_wait_t) dlsym(RTLD_DEFAULT, "epoll_wait");
if ((epoll_create_func == NULL) || (epoll_ctl_func == NULL) ||
(epoll_wait_func == NULL)) {
JNU_ThrowInternalError(env, "unable to get address of epoll functions, pre-2.6 kernel?");
}
}
具体程序的流程我还是不够清楚，还有待进一步深入了解。