JNIEXPORT void JNICALL
Java_org_apache_hadoop_net_unix_DomainSocketWatcher_00024FdSet_add(
JNIEnv *env, jobject obj, jint fd)
{
struct fd_set_data *sd, *nd;
struct pollfd *pollfd;
sd = (struct fd_set_data*)(intptr_t)(*env)->
GetLongField(env, obj, fd_set_data_fid);
if (sd->used_size + 1 > sd->alloc_size) {
nd = realloc(sd, sizeof(struct fd_set_data) +
(sizeof(struct pollfd) * sd->alloc_size * 2));
if (!nd) {
(*env)->Throw(env, newRuntimeException(env, "out of memory adding "
"another fd to DomainSocketWatcher#FdSet. we have %d already",
sd->alloc_size));
return;
}
nd->alloc_size = nd->alloc_size * 2;
(*env)->SetLongField(env, obj, fd_set_data_fid, (jlong)(intptr_t)nd);
sd = nd;
}
pollfd = &sd->pollfd[sd->used_size];
sd->used_size++;
pollfd->fd = fd;
pollfd->events = POLLIN | POLLHUP;
pollfd->revents = 0;
}
JNIEXPORT void JNICALL
Java_org_apache_hadoop_net_unix_DomainSocketWatcher_00024FdSet_remove(
JNIEnv *env, jobject obj, jint fd)
{
struct fd_set_data *sd;
struct pollfd *pollfd = NULL, *last_pollfd;
int used_size, i;
sd = (struct fd_set_data*)(intptr_t)(*env)->
GetLongField(env, obj, fd_set_data_fid);
used_size = sd->used_size;
for (i = 0; i < used_size; i++) {
if (sd->pollfd[i].fd == fd) {
pollfd = sd->pollfd + i;
break;
}
}
if (pollfd == NULL) {
(*env)->Throw(env, newRuntimeException(env, "failed to remove fd %d "
"from the FdSet because it was never present.", fd));
return;
}
last_pollfd = sd->pollfd + (used_size - 1);
if (used_size > 1) {
// Move last pollfd to the new empty slot if needed
pollfd->fd = last_pollfd->fd;
pollfd->events = last_pollfd->events;
pollfd->revents = last_pollfd->revents;
}
memset(last_pollfd, 0, sizeof(struct pollfd));
sd->used_size--;
}
JNIEXPORT jlong JNICALL
Java_org_apache_hadoop_net_unix_DomainSocketWatcher_00024FdSet_alloc0(
JNIEnv *env, jclass clazz)
{
struct fd_set_data *sd;
sd = calloc(1, sizeof(struct fd_set_data) +
(sizeof(struct pollfd) * FD_SET_DATA_MIN_SIZE));
if (!sd) {
(*env)->Throw(env, newRuntimeException(env, "out of memory allocating "
"DomainSocketWatcher#FdSet"));
return 0L;
}
sd->alloc_size = FD_SET_DATA_MIN_SIZE;
sd->used_size = 0;
return (jlong)(intptr_t)sd;
}
JNIEXPORT void JNICALL
Java_org_apache_hadoop_security_JniBasedUnixGroupsMapping_anchorNative(
JNIEnv *env, jclass clazz)
{
jobject string_clazz;
g_log_error_method = (*env)->GetStaticMethodID(env, clazz, "logError",
"(ILjava/lang/String;)V");
if (!g_log_error_method) {
return; // an exception has been raised
}
string_clazz = (*env)->FindClass(env, "java/lang/String");
if (!string_clazz) {
return; // an exception has been raised
}
g_string_clazz = (*env)->NewGlobalRef(env, string_clazz);
if (!g_string_clazz) {
jthrowable jthr = newRuntimeException(env,
"JniBasedUnixGroupsMapping#anchorNative: failed to make "
"a global reference to the java.lang.String class\n");
(*env)->Throw(env, jthr);
return;
}
}
JNIEXPORT jobject JNICALL
Java_org_apache_hadoop_net_unix_DomainSocketWatcher_00024FdSet_getAndClearReadableFds(
JNIEnv *env, jobject obj)
{
int *carr = NULL;
jobject jarr = NULL;
struct fd_set_data *sd;
int used_size, num_readable = 0, i, j;
jthrowable jthr = NULL;
sd = (struct fd_set_data*)(intptr_t)(*env)->
GetLongField(env, obj, fd_set_data_fid);
used_size = sd->used_size;
for (i = 0; i < used_size; i++) {
// We check for both POLLIN and POLLHUP, because on some OSes, when a socket
// is shutdown(), it sends POLLHUP rather than POLLIN.
if ((sd->pollfd[i].revents & POLLIN) ||
(sd->pollfd[i].revents & POLLHUP)) {
num_readable++;
} else {
sd->pollfd[i].revents = 0;
}
}
if (num_readable > 0) {
carr = malloc(sizeof(int) * num_readable);
if (!carr) {
jthr = newRuntimeException(env, "failed to allocate a temporary array "
"of %d ints", num_readable);
goto done;
}
j = 0;
for (i = 0; ((i < used_size) && (j < num_readable)); i++) {
if ((sd->pollfd[i].revents & POLLIN) ||
(sd->pollfd[i].revents & POLLHUP)) {
carr[j] = sd->pollfd[i].fd;
j++;
sd->pollfd[i].revents = 0;
}
}
if (j != num_readable) {
jthr = newRuntimeException(env, "failed to fill entire carr "
"array of size %d: only filled %d elements", num_readable, j);
goto done;
}
}
jarr = (*env)->NewIntArray(env, num_readable);
if (!jarr) {
jthr = (*env)->ExceptionOccurred(env);
(*env)->ExceptionClear(env);
goto done;
}
if (num_readable > 0) {
(*env)->SetIntArrayRegion(env, jarr, 0, num_readable, carr);
jthr = (*env)->ExceptionOccurred(env);
if (jthr) {
(*env)->ExceptionClear(env);
goto done;
}
}
done:
free(carr);
if (jthr) {
(*env)->DeleteLocalRef(env, jarr);
(*env)->Throw(env, jthr);
}
return jarr;
}
