ACE
6.4.2
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Class that acquires, renews, and releases a process-local synchronization token. More...
#include <Local_Tokens.h>
Public Types | |
enum | PROXY_TYPE { READER, WRITER } |
These are the types that proxies can be. More... | |
Public Types inherited from ACE_Tokens | |
enum | TOKEN_TYPES { MUTEX, RWLOCK } |
typedef ACE_Unbounded_Stack< ACE_TPQ_Entry * > | OWNER_STACK |
Stack of owners. More... | |
Public Member Functions | |
ACE_RW_Token (const ACE_TCHAR *name) | |
Constructor. More... | |
virtual | ~ACE_RW_Token (void) |
Destructor. More... | |
virtual int | acquire (ACE_TPQ_Entry *caller, int ignore_deadlock, int notify) |
virtual int | tryacquire (ACE_TPQ_Entry *caller) |
Same as acquire except fails on would block. More... | |
virtual int | renew (ACE_TPQ_Entry *caller, int requeue_position) |
virtual int | release (ACE_TPQ_Entry *caller) |
void | dump (void) const |
Dump the state of the class. More... | |
virtual int | type (void) const |
Returns READER or WRITER. More... | |
virtual int | owners (OWNER_STACK &o, const ACE_TCHAR *id) |
virtual int | is_waiting_for (const ACE_TCHAR *id) |
Returns 1 if id is waiting for this token. 0 otherwise. More... | |
virtual int | is_owner (const ACE_TCHAR *id) |
Returns 1 if id is an owner of this token. 0 otherwise. More... | |
Public Member Functions inherited from ACE_Tokens | |
ACE_Tokens (void) | |
Null constructor. More... | |
virtual | ~ACE_Tokens (void) |
Destructor. More... | |
void | make_owner (ACE_TPQ_Entry *caller) |
void | remove (ACE_TPQ_Entry *caller) |
Remove the caller from the waiter list. More... | |
virtual ACE_Token_Proxy_Queue * | waiters (void) |
Return the queue of waiters. More... | |
virtual int | no_of_waiters (void) |
const ACE_TCHAR * | owner_id (void) |
The current owner. More... | |
const ACE_TCHAR * | name (void) |
Token name. More... | |
void | inc_reference (void) |
int | dec_reference (void) |
void | dump (void) const |
Dump the state of the class. More... | |
void | visit (int v) |
Mark or unmark the token as visited. More... | |
int | visited (void) |
Check if the token has been visited. More... | |
ACE_TPQ_Entry * | owner (void) |
All the data of the current owner. More... | |
Protected Member Functions | |
void | notify_new_owner (ACE_TPQ_Entry *caller) |
Sets the new owner. More... | |
Protected Attributes | |
int | num_writers_ |
The number of waiting writers. More... | |
ACE_TOKEN_CONST::MUTEX | lock_ |
ACE_Mutex_Token used to lock internal data structures. More... | |
Protected Attributes inherited from ACE_Tokens | |
int | visited_ |
For the deadlock detection algorithm. More... | |
int | reference_count_ |
Reference count. More... | |
ACE_Token_Proxy_Queue | waiters_ |
List of client's owning and waiting the token. More... | |
ACE_TCHAR | token_name_ [ACE_MAXTOKENNAMELEN] |
Name of token. More... | |
Class that acquires, renews, and releases a process-local synchronization token.
Not a public interface. This class is a more general-purpose synchronization mechanism than SunOS 5.x mutexes. For example, it implements "recursive mutex" semantics, where a thread that owns the token can reacquire it without deadlocking. In addition, threads that are blocked awaiting the token are serviced in strict FIFO order as other threads release the token (SunOS 5.x mutexes don't strictly enforce an acquisition order).
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explicit |
Constructor.
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virtual |
Destructor.
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Returns 0 on success, -1 on failure with <ACE_Log_Msg::errnum> as the reason. If errnum == EWOULDBLOCK, and notify == 1, <ACE_Token_Proxy::sleep_hook> has been called on the current owner of the token. If ignore_deadlock is passed as 1 and errnum == EDEADLK, then deadlock was detected via ACE_Token_Manager.
Implements ACE_Tokens.
void ACE_RW_Token::dump | ( | void | ) | const |
Dump the state of the class.
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Returns 1 if id is an owner of this token. 0 otherwise.
Implements ACE_Tokens.
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Returns 1 if id is waiting for this token. 0 otherwise.
Implements ACE_Tokens.
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protected |
Sets the new owner.
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Returns a stack of the current owners. Returns -1 on error, 0 on success. If id is non-zero, returns 1 if id is an owner.
Implements ACE_Tokens.
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Relinquish the token. If there are any waiters then the next one in line gets it. If the caller is not the owner, caller is removed from the waiter list.
Implements ACE_Tokens.
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An optimized method that efficiently reacquires the token if no other threads are waiting. This is useful for situations where you don't want to degrade the quality of service if there are other threads waiting to get the token. If <requeue_position> == -1 and there are other threads waiting to obtain the token we are queued at the end of the list of waiters. If <requeue_position>
-1 then it indicates how many entries to skip over before
inserting our thread into the list of waiters (e.g., <requeue_position> == 0 means "insert at front of the queue"). Renew has the rather odd semantics such that if there are other waiting threads it will give up the token even if the nesting_level_ > 1. I'm not sure if this is really the right thing to do (since it makes it possible for shared data to be changed unexpectedly) so use with caution... Returns 0 on success, -1 on failure with <ACE_Log_Msg::errnum> as the reason. If errnum == EWOULDBLOCK, and notify == 1, <ACE_Token_Proxy::sleep_hook> has been called on the current owner of the token.
Implements ACE_Tokens.
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Same as acquire except fails on would block.
Implements ACE_Tokens.
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Returns READER or WRITER.
Implements ACE_Tokens.
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protected |
ACE_Mutex_Token used to lock internal data structures.
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protected |
The number of waiting writers.