/*++
*
* Read Lock Section
*
--*/
//
// Tries to enter the read lock if this is the first reader
// or a recursive acquisition.
//
private bool FastTryEnterRead(int tid, out OwnerEntry oce) {
oce = null;
//
// Try to enter the read lock as the first reader.
//
if (rwlock.state == 0 &&
Interlocked.CompareExchange(ref rwlock.state, 1, 0) == 0) {
firstReader = tid;
firstReaderCount = 1;
return true;
}
//
// Check if this is a recursive acquisition and the current
// thread is the first reader.
//
if (firstReader == tid) {
firstReaderCount++;
return true;
}
//
// Check if the current thread is already a read lock owner.
//
if (readOwner.LookupEntry(tid, out oce)) {
oce.count++;
return true;
}
return false;
}
protected override async void OnAppearing()
{
base.OnAppearing();
await Task.Delay(200);
OwnerEntry.Focus();
}
/// <summary>
/// Adds an owner to a group.
/// </summary>
/// <param name="ownerEmail">Email of the owner that is being added to the group</param>
/// <param name="groupId">The group to which the member is being added</param>
/// <returns>a <code>OwnerEntry</code> containing the results of the
/// creation</returns>
public OwnerEntry AddOwnerToGroup(String ownerEmail, String groupId)
{
String requestUri = String.Format("{0}/{1}/{2}/{3}",
AppsGroupsNameTable.AppsGoogleGroupsBaseFeedUri,
domain,
groupId,
AppsGroupsNameTable.owner);
OwnerEntry entry = new OwnerEntry();
entry.Email = ownerEmail;
return(Insert(requestUri, entry));
}
//
// Looks up for an entry belonging to the specified thread id.
//
internal bool LookupEntry(int tid, out OwnerEntry entry) {
int hi = tid & HASH_TABLE_MASK;
entry = null;
OwnerEntry p = table[hi].tail;
while (p != null) {
if (tid == p.key) {
entry = p;
return true;
}
if (entry == null && p.key == OwnerEntry.FREE_ENTRY) {
entry = p;
}
p = p.next;
}
return false;
}
/// <summary>
/// Checks whether an user is a group owner.
/// </summary>
/// <param name="ownerEmail">Email of the owner that is being checked</param>
/// <param name="groupId">The ID of the group for which you wish to check the ownership</param>
/// <returns>True if the user is an owner of the group, false otherwise</returns>
public bool IsOwner(String ownerEmail, String groupId)
{
try {
OwnerEntry entry = RetrieveOwner(ownerEmail, groupId);
return(entry != null);
} catch (GDataRequestException e) {
AppsException appsException = AppsException.ParseAppsException(e);
if (appsException == null)
{
return(false);
}
if (appsException.ErrorCode.Equals(AppsException.EntityDoesNotExist))
{
return(false);
}
else
{
throw appsException;
}
}
}
//
// Allocates an owner entry for the specified thread id.
//
internal OwnerEntry AllocateEntry(int tid, OwnerEntry hint) {
if (hint != null && hint.CasKey(OwnerEntry.FREE_ENTRY, tid)) {
hint.count = 1;
return hint;
}
int hi = tid & HASH_TABLE_MASK;
OwnerEntry p = table[hi].tail;
while (p != null) {
if (p.CasKey(OwnerEntry.FREE_ENTRY, tid)) {
p.count = 1;
return p;
}
p = p.next;
}
OwnerEntry ne = new OwnerEntry(tid);
do {
p = table[hi].tail;
ne.next = p;
if (table[hi].CasTail(p, ne)) {
return ne;
}
} while (true);
}
internal bool CasTail(OwnerEntry t, OwnerEntry nt) {
return (tail == t &&
Interlocked.CompareExchange<OwnerEntry>(ref tail, nt, t) == t);
}
