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#include "ace/Token_Manager.h"
#if defined (ACE_HAS_TOKENS_LIBRARY)
#include "ace/Object_Manager.h"
#include "ace/os_include/os_typeinfo.h"
#if !defined (__ACE_INLINE__)
#include "ace/Token_Manager.inl"
#endif /* __ACE_INLINE__ */
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
// singleton token manager
ACE_Token_Manager *ACE_Token_Manager::token_manager_ = 0;
ACE_Token_Manager::ACE_Token_Manager ()
{
ACE_TRACE ("ACE_Token_Manager::ACE_Token_Manager");
}
ACE_Token_Manager::~ACE_Token_Manager ()
{
ACE_TRACE ("ACE_Token_Manager::~ACE_Token_Manager");
COLLECTION::ITERATOR iterator (collection_);
for (COLLECTION::ENTRY *temp = 0;
iterator.next (temp) != 0;
iterator.advance ())
{
// @ should I be doing an unbind here?
delete temp->int_id_;
// The ext_id_'s delete themselves when the array of
// COLLECTION::ENTRYs goes away.
}
}
ACE_Token_Manager *
ACE_Token_Manager::instance (void)
{
ACE_TRACE ("ACE_Token_Manager::instance");
// This first check is to avoid acquiring the mutex in the common
// case. Double-Check pattern rules.
if (token_manager_ == 0)
{
#if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0)
ACE_TOKEN_CONST::MUTEX *lock =
ACE_Managed_Object<ACE_TOKEN_CONST::MUTEX>::get_preallocated_object
(ACE_Object_Manager::ACE_TOKEN_MANAGER_CREATION_LOCK);
ACE_GUARD_RETURN (ACE_TOKEN_CONST::MUTEX, ace_mon, *lock, 0);
#endif /* ACE_MT_SAFE */
if (token_manager_ == 0)
{
ACE_NEW_RETURN (token_manager_,
ACE_Token_Manager,
0);
// Register for destruction with ACE_Object_Manager.
ACE_Object_Manager::at_exit (token_manager_, 0, typeid (token_manager_).name ());
}
}
return token_manager_;
}
void
ACE_Token_Manager::get_token (ACE_Token_Proxy *proxy,
const ACE_TCHAR *token_name)
{
ACE_TRACE ("ACE_Token_Manager::get_token");
// Hmm. I think this makes sense. We perform our own locking here
// (see safe_acquire.) We have to make sure that only one thread
// uses the collection at a time.
ACE_GUARD (ACE_TOKEN_CONST::MUTEX, ace_mon, this->lock_);
TOKEN_NAME name (token_name);
if (collection_.find (name, proxy->token_) == -1)
// We did not find one in the collection.
{
// Make one.
proxy->token_ = proxy->create_token (token_name);
// Put it in the collection.
if (collection_.bind (name, proxy->token_) == -1)
{
delete proxy->token_;
proxy->token_ = 0;
}
}
if (proxy->token_ != 0)
proxy->token_->inc_reference ();
// We may be returning proxy->token_ == 0 if new failed, caller must
// check.
}
// 0. check_deadlock (TOKEN)
// 1. if TOKEN->visited (), return 0.
// 2. mark TOKEN visited.
// 3. get ALL_OWNERS
// 4. if CLIENT in ALL_OWNERS, return *DEADLOCK*.
// 5. for each OWNER in ALL_OWNERS,
// 6. if OWNER is not waiting for a NEW_TOKEN, continue.
// 7. else, if check_deadlock (NEW_TOKEN) == 1, return *DEADLOCK*
// 8. return 0.
int
ACE_Token_Manager::check_deadlock (ACE_Token_Proxy *proxy)
{
ACE_TRACE ("ACE_Token_Manager::check_deadlock");
// Start the recursive deadlock detection algorithm.
int result = this->check_deadlock (proxy->token_, proxy);
// Whether or not we detect deadlock, we have to unmark all tokens
// for the next time.
COLLECTION::ITERATOR iterator (collection_);
for (COLLECTION::ENTRY *temp = 0;
iterator.next (temp) != 0;
iterator.advance ())
temp->int_id_->visit (0);
return result;
}
int
ACE_Token_Manager::check_deadlock (ACE_Tokens *token, ACE_Token_Proxy *proxy)
{
ACE_TRACE ("ACE_Token_Manager::check_deadlock");
if (token->visited ())
return 0;
token->visit (1);
ACE_Tokens::OWNER_STACK owners;
int is_owner = token->owners (owners, proxy->client_id ());
switch (is_owner)
{
case -1:
// Error.
return -1;
case 1:
// The caller is an owner, so we have a deadlock situation.
if (debug_)
{
ACELIB_DEBUG ((LM_DEBUG, ACE_TEXT ("(%t) Deadlock detected.\n")));
ACELIB_DEBUG ((LM_DEBUG, ACE_TEXT ("%s owns %s and is waiting for %s.\n"),
proxy->client_id (),
token->name (),
proxy->token_->name ()));
}
return 1;
case 0:
default:
// Recurse on each owner.
while (!owners.is_empty ())
{
ACE_TPQ_Entry *e;
owners.pop (e);
// If the owner is waiting on another token, recurse.
ACE_Tokens *twf = this->token_waiting_for (e->client_id ());
if ((twf != 0) &&
(this->check_deadlock (twf, proxy) == 1))
{
if (debug_)
{
ACELIB_DEBUG ((LM_DEBUG,
ACE_TEXT ("%s owns %s and is waiting for %s.\n"),
e->client_id (),
token->name (),
twf->name ()));
}
return 1;
}
// else, check the next owner.
}
// We've checked all the owners and found no deadlock.
return 0;
}
}
ACE_Tokens *
ACE_Token_Manager::token_waiting_for (const ACE_TCHAR *client_id)
{
COLLECTION::ITERATOR iterator (collection_);
for (COLLECTION::ENTRY *temp = 0;
iterator.next (temp) != 0;
iterator.advance ())
{
if (temp->int_id_->is_waiting_for (client_id))
return temp->int_id_;
}
// nothing was found, return NULL.
return 0;
}
// Notify the token manager that a token is has been released. If
// as a result, there is no owner of the token, the token is
// deleted.
void
ACE_Token_Manager::release_token (ACE_Tokens *&token)
{
ACE_TRACE ("ACE_Token_Manager::release_token");
// again, let's perform our own locking here.
ACE_GUARD (ACE_TOKEN_CONST::MUTEX, ace_mon, this->lock_);
if (token->dec_reference () == 0)
{
// No one has the token, so we can delete it and remove it from
// our collection. First, let's get it from the collection.
TOKEN_NAME token_name (token->name ());
ACE_Tokens *temp;
if (collection_.unbind (token_name, temp) == -1)
// we did not find one in the collection
{
errno = ENOENT;
ACELIB_ERROR ((LM_ERROR, ACE_TEXT ("Token Manager could not release %s:%d\n"),
token->name (), token->type ()));
// @@ bad
}
else
// we found it
{
// sanity pointer comparison. The token referenced by the
// proxy better be the one we found in the list.
ACE_ASSERT (token == temp);
delete token; // or delete temp
// we set their token to zero. if the calling proxy is
// still going to be used, it had better check it's token
// value before calling a method on it!
token = 0;
}
}
// else
// someone is still interested in the token, so keep it around.
}
void
ACE_Token_Manager::dump (void) const
{
#if defined (ACE_HAS_DUMP)
ACE_TRACE ("ACE_Token_Manager::dump");
ACELIB_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
ACELIB_DEBUG ((LM_DEBUG, ACE_TEXT ("ACE_Token_Manager::dump:\n")));
ACELIB_DEBUG ((LM_DEBUG, ACE_TEXT ("lock_\n")));
lock_.dump ();
ACELIB_DEBUG ((LM_DEBUG, ACE_TEXT ("collection_\n")));
collection_.dump ();
ACELIB_DEBUG ((LM_DEBUG, ACE_END_DUMP));
#endif /* ACE_HAS_DUMP */
}
ACE_END_VERSIONED_NAMESPACE_DECL
#endif /* ACE_HAS_TOKENS_LIBRARY */
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