XrdSsiShMam Class Reference

#include <XrdSsiShMam.hh>

Inheritance diagram for XrdSsiShMam:
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List of all members.

Classes

struct  MemItem
class  XLockHelper

Public Types

enum  LockType { ROLock = 0, RWLock = 1 }

Public Member Functions

bool AddItem (void *newdata, void *olddata, const char *key, int hash, bool replace=false)
bool Attach (int tout, bool isrw=false)
bool Create (XrdSsiShMat::CRZParms &parms)
bool Export ()
bool DelItem (void *data, const char *key, int hash)
void Detach ()
 Detach the map from the shared memory.
bool Enumerate (void *&jar, char *&key, void *&val)
bool Enumerate (void *&jar)
bool GetItem (void *data, const char *key, int hash)
int Info (const char *vname, char *buff=0, int blen=0)
bool Resize (XrdSsiShMat::CRZParms &parms)
bool Sync ()
bool Sync (bool dosync, bool syncdo)
bool Sync (int syncqsz)
 XrdSsiShMam (XrdSsiShMat::NewParms &parms)
 ~XrdSsiShMam ()

Private Member Functions

bool ExportIt (bool fLocked)
int Find (MemItem *&theItem, MemItem *&prvItem, const char *key, int &hash)
bool Flush ()
int HashVal (const char *key)
bool Lock (bool doRW=false, bool nowait=false)
MemItemNewItem ()
bool ReMap (LockType iHave)
void RetItem (MemItem *iP)
void SetLocking (bool isrw)
void SwapMap (XrdSsiShMam &newMap)
void Snooze (int sec)
void UnLock (bool isrw)
void Updated (int mOff)
void Updated (int mOff, int mLen)
 Atomic (int)*shmIndex

Private Attributes

pthread_mutex_t lkMutex
pthread_rwlock_t myMutex
char * shmTemp
long long shmSize
char * shmBase
int shmSlots
int shmItemSz
int shmInfoSz
int verNum
int keyPos
int maxKLen
int shmFD
int timeOut
int lkCount
int syncOpt
int syncQWR
int syncLast
int syncQSZ
int accMode
bool isRW
bool lockRO
bool lockRW
bool reUse
bool multW
bool useAtomic
bool syncBase
bool syncOn

Member Enumeration Documentation

Enumerator:
ROLock 
RWLock 

Constructor & Destructor Documentation

XrdSsiShMam::XrdSsiShMam ( XrdSsiShMat::NewParms parms  ) 
XrdSsiShMam::~XrdSsiShMam (  )  [inline]

References Detach(), lkMutex, and myMutex.


Member Function Documentation

bool XrdSsiShMam::AddItem ( void *  newdata,
void *  olddata,
const char *  key,
int  hash,
bool  replace = false 
) [virtual]

Add an item to the shared memory table.

Parameters:
newdata Pointer to the data to be added.
olddata Pointer to the area where the replaced data, if any, is to be placed.
key The key associated with the data that is to be added.
hash The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed.
replace When true, if the key exists, the data associated with the key is replaced. When false, if the key exists, the addition fails with errno set to EEXIST.
Returns:
true The addition/replacement succeeded. If the key was actually replaced errno is set to EEXIST else it is set to 0.
false The addition/replacement failed; errno indicates reason.

Implements XrdSsiShMat.

XrdSsiShMam::Atomic ( int   )  [private]
bool XrdSsiShMam::Attach ( int  tout,
bool  isrw = false 
) [virtual]

Attach this object to the shared memory associated with this object at creation time (see New() method). The attach operation waits until the shared memory file is available. At that time, the file is memory mapped.

Parameters:
tout The maximum number of seconds to wait for the shared memory file to become available. If tout is zero, then the file must be immediately available. If the value is negative then the attach waits as long as needed. When tout is reached the attach fails with errno set to ETIMEDOUT.
isrw When true the file is mapped to writable memory and allows updates to the table. If false, the shared memory is made read/only and may be significantly faster to access.
Returns:
true - The shared memory was attached, the table can be used.
false - The shared memory could not be attached, errno holds reason.

Implements XrdSsiShMat.

bool XrdSsiShMam::Create ( XrdSsiShMat::CRZParms parms  )  [virtual]

Implements XrdSsiShMat.

bool XrdSsiShMam::DelItem ( void *  data,
const char *  key,
int  hash 
) [virtual]

Delete an item from the table.

Parameters:
data Pointer to the area to receive the value of the deleted key. If the pointer is nil, then the key value is not returned.
key Pointer to the key of length <= MaxKLen.
hash The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed.
Returns:
true - The key and data have been deleted. This is always returned when data is nil.
false - The key and data either not deleted or the key does not exist and data was not nil. The errno value decribes why. Typical reason: the key was not found (errno == ENOENT).

Implements XrdSsiShMat.

void XrdSsiShMam::Detach (  )  [virtual]

Detach the map from the shared memory.

Implements XrdSsiShMat.

Referenced by ~XrdSsiShMam().

bool XrdSsiShMam::Enumerate ( void *&  jar  )  [virtual]

Terminate an active enumeration. An active enumeration is any enumeration where the previous form of Enumerate() did not return false. Terminating an active enumeration releases all of the enumeration resources allocated.

Parameters:
jar The opaque cookie initialized by a previous call to Enumerate() requesting the next key-value pair.
Returns:
true The enumeration has been terminated and the jar was deleted and the jar pointer is set to zero. Keys are returned in arbitrary order and not all keys may be returned if the map is being actively updated.
false The jar pointer was zero; no enumeration was active.

Implements XrdSsiShMat.

bool XrdSsiShMam::Enumerate ( void *&  jar,
char *&  key,
void *&  val 
) [virtual]

Enumerate the keys and assocaited values.

Parameters:
jar An opaque cookie that tracks progress. It should be initialized to zero and otherwise not touched. The same jar must be used for all successive calls. The jar is deleted when false is returned (also see the next Enumerate method).
key The pointer variable where the location of the key is returned upon success.
val The pointer variable where the location f the key values is to be returned upon success.
Returns:
true A key and val pointers have been set. Keys are returned in arbitrary order and not all keys may be returned if the map is being actively updated.
false Key not returned; errno holds the reason. Typically, ENOENT there ae no more keys. Other errors may also be reflected. Whne false is returned the jar is deleted and the pointer to it set to zero.

Implements XrdSsiShMat.

bool XrdSsiShMam::Export (  )  [virtual]

Export a newly created table (i.e. see Create()).

Returns:
true - The table has been exported and is now visible to others.
false - The export failed, the errno value describes the reason.

Implements XrdSsiShMat.

bool XrdSsiShMam::ExportIt ( bool  fLocked  )  [private]
int XrdSsiShMam::Find ( MemItem *&  theItem,
MemItem *&  prvItem,
const char *  key,
int &  hash 
) [private]
bool XrdSsiShMam::Flush (  )  [private]
bool XrdSsiShMam::GetItem ( void *  data,
const char *  key,
int  hash 
) [virtual]

Get an item from the table.

Parameters:
data Pointer to an area to receive the value associated with key. If the pointer is nil, then the key value is not returned.
key Pointer to the key of length <= MaxKLen.
hash The hash of the key that is to be used to lookup the key. If the value is zero, an internal hash is computed.
Returns:
true - The key was found and if data was not nil, contains the value associated key.
false - The key not found; errno holds the reason (typically is ENOENT but may be some other reason).

Implements XrdSsiShMat.

int XrdSsiShMam::HashVal ( const char *  key  )  [private]
int XrdSsiShMam::Info ( const char *  vname,
char *  buff = 0,
int  blen = 0 
) [virtual]

Return information about the table.

Parameters:
vname Pointer to the variable name whose value is wanted. A particular implementation may not support all variable and may support variables not listed here. These are for the default implementation unless otherwise noted. They are: hash - name of hash being used. impl - The table implementation being used. indexsz - Number of index entries indexused - Number of index entries in use keys - Number of keys in the bale. keys/indexused is the hash table collision factor keysfree - Number of keys that can still be added maxkeylen - Longest allowed key multw - If table supports multiple writers, else 0 reuse - If table allows object reuse, else 0 type - Name of the data type in the table. typesz - The number of bytes in the table's data type
buff - Pointer to the buffer to receive text values. Variables that return text are: hash, impl, and type. A buffer must be supplied in any of these variables are requested. If buff is nill or too small a -1 is returned with errno set to EMSGSIZE.
blen The length of the buffer.
Returns:
>=0 - The variable's value or the length of the text information.
< 0 - The variable's value could not be returned; errno has the error code describing the reason, typically ENOSYS.

Implements XrdSsiShMat.

bool XrdSsiShMam::Lock ( bool  doRW = false,
bool  nowait = false 
) [private]
MemItem* XrdSsiShMam::NewItem (  )  [private]
bool XrdSsiShMam::ReMap ( LockType  iHave  )  [private]
bool XrdSsiShMam::Resize ( XrdSsiShMat::CRZParms parms  )  [virtual]

Resize a shared memory segment and associated file specified at object instantiation (see New() method). Resizing is implementation specific but may involve creating a new table and exporting it.

Parameters:
parms Resize parameters. See the CRZParms struct for details. For resize, zero values or unspecified flags use the existing table values.
Returns:
true - The shared memory was resized, the table can be used.
false - The shared memory could not be resized, errno holds reason.

Implements XrdSsiShMat.

void XrdSsiShMam::RetItem ( MemItem iP  )  [private]
void XrdSsiShMam::SetLocking ( bool  isrw  )  [private]
void XrdSsiShMam::Snooze ( int  sec  )  [private]
void XrdSsiShMam::SwapMap ( XrdSsiShMam newMap  )  [private]
bool XrdSsiShMam::Sync ( int  synqsz  )  [virtual]

Set the sync defer queue size.

Parameters:
synqsz The maximum number of modified pages before flushing.
Returns:
true - Operation completed successfully.
false - Operation failed; errno holds the error code explaining why.

Implements XrdSsiShMat.

bool XrdSsiShMam::Sync ( bool  dosync,
bool  syncdo 
) [virtual]

Turn memry synchronization on or off.

Parameters:
dosync When true, modified table pages are written back to the backing file. The synchronous or async nature of the write is controlled by the second parameter. When false, memory-file synchronization is turned off (initial setting).
syncdo When true, synchronization is done in the forground. That is, a call triggering a sync will not return until complete. When false, synchronization is done in the background.
Returns:
true - Operation completed successfully.
false - Operation failed; errno holds the error code explaining why.

Implements XrdSsiShMat.

bool XrdSsiShMam::Sync (  )  [virtual]

Synchronize all modified pages to the associated backing file.

Returns:
true - Operation completed successfully.
false - Operation failed; errno holds the error code explaining why.

Implements XrdSsiShMat.

void XrdSsiShMam::UnLock ( bool  isrw  )  [private]
void XrdSsiShMam::Updated ( int  mOff,
int  mLen 
) [private]
void XrdSsiShMam::Updated ( int  mOff  )  [private]

Member Data Documentation

int XrdSsiShMam::accMode [private]
bool XrdSsiShMam::isRW [private]
int XrdSsiShMam::keyPos [private]
int XrdSsiShMam::lkCount [private]
pthread_mutex_t XrdSsiShMam::lkMutex [private]

Referenced by ~XrdSsiShMam().

bool XrdSsiShMam::lockRO [private]
bool XrdSsiShMam::lockRW [private]
int XrdSsiShMam::maxKLen [private]
bool XrdSsiShMam::multW [private]
pthread_rwlock_t XrdSsiShMam::myMutex [private]
bool XrdSsiShMam::reUse [private]
char* XrdSsiShMam::shmBase [private]
int XrdSsiShMam::shmFD [private]
int XrdSsiShMam::shmInfoSz [private]
int XrdSsiShMam::shmItemSz [private]
long long XrdSsiShMam::shmSize [private]
int XrdSsiShMam::shmSlots [private]
char* XrdSsiShMam::shmTemp [private]
bool XrdSsiShMam::syncBase [private]
int XrdSsiShMam::syncLast [private]
bool XrdSsiShMam::syncOn [private]
int XrdSsiShMam::syncOpt [private]
int XrdSsiShMam::syncQSZ [private]
int XrdSsiShMam::syncQWR [private]
int XrdSsiShMam::timeOut [private]
bool XrdSsiShMam::useAtomic [private]
int XrdSsiShMam::verNum [private]

The documentation for this class was generated from the following file:
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