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ACE_Message_Block Class Reference

Stores messages for use throughout ACE (particularly in an ACE_Message_Queue). More...

#include <Message_Block.h>

Collaboration diagram for ACE_Message_Block:
Collaboration graph
[legend]

Public Types

enum  {
  MB_DATA = 0x01, MB_PROTO = 0x02, MB_BREAK = 0x03, MB_PASSFP = 0x04,
  MB_EVENT = 0x05, MB_SIG = 0x06, MB_IOCTL = 0x07, MB_SETOPTS = 0x08,
  MB_IOCACK = 0x81, MB_IOCNAK = 0x82, MB_PCPROTO = 0x83, MB_PCSIG = 0x84,
  MB_READ = 0x85, MB_FLUSH = 0x86, MB_STOP = 0x87, MB_START = 0x88,
  MB_HANGUP = 0x89, MB_ERROR = 0x8a, MB_PCEVENT = 0x8b, MB_NORMAL = 0x00,
  MB_PRIORITY = 0x80, MB_USER = 0x200
}
 
enum  { DONT_DELETE = 01, USER_FLAGS = 0x1000 }
 
typedef int ACE_Message_Type
 
typedef unsigned long Message_Flags
 

Public Member Functions

 ACE_Message_Block (ACE_Allocator *message_block_allocator=0)
 Create an empty message. More...
 
 ACE_Message_Block (ACE_Data_Block *data_block, Message_Flags flags=0, ACE_Allocator *message_block_allocator=0)
 
 ACE_Message_Block (const char *data, size_t size=0, unsigned long priority=ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY)
 
 ACE_Message_Block (size_t size, ACE_Message_Type type=MB_DATA, ACE_Message_Block *cont=0, const char *data=0, ACE_Allocator *allocator_strategy=0, ACE_Lock *locking_strategy=0, unsigned long priority=ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY, const ACE_Time_Value &execution_time=ACE_Time_Value::zero, const ACE_Time_Value &deadline_time=ACE_Time_Value::max_time, ACE_Allocator *data_block_allocator=0, ACE_Allocator *message_block_allocator=0)
 
 ACE_Message_Block (const ACE_Message_Block &mb, size_t align)
 
int init (const char *data, size_t size=0)
 
int init (size_t size, ACE_Message_Type type=MB_DATA, ACE_Message_Block *cont=0, const char *data=0, ACE_Allocator *allocator_strategy=0, ACE_Lock *locking_strategy=0, unsigned long priority=ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY, const ACE_Time_Value &execution_time=ACE_Time_Value::zero, const ACE_Time_Value &deadline_time=ACE_Time_Value::max_time, ACE_Allocator *data_block_allocator=0, ACE_Allocator *message_block_allocator=0)
 
virtual ~ACE_Message_Block (void)
 
ACE_Message_Type msg_type (void) const
 Get type of the message. More...
 
void msg_type (ACE_Message_Type type)
 Set type of the message. More...
 
int is_data_msg (void) const
 Find out what type of message this is. More...
 
ACE_Message_Type msg_class (void) const
 
Message_Flags set_flags (Message_Flags more_flags)
 
Message_Flags clr_flags (Message_Flags less_flags)
 
Message_Flags flags (void) const
 Get the current message flags. More...
 
Message_Flags set_self_flags (ACE_Message_Block::Message_Flags more_flags)
 
Message_Flags clr_self_flags (ACE_Message_Block::Message_Flags less_flags)
 
Message_Flags self_flags (void) const
 Get the current message flags. More...
 
unsigned long msg_priority (void) const
 Get priority of the message. More...
 
void msg_priority (unsigned long priority)
 Set priority of the message. More...
 
const ACE_Time_Valuemsg_execution_time (void) const
 Get execution time associated with the message. More...
 
void msg_execution_time (const ACE_Time_Value &et)
 Set execution time associated with the message. More...
 
const ACE_Time_Valuemsg_deadline_time (void) const
 Get absolute time of deadline associated with the message. More...
 
void msg_deadline_time (const ACE_Time_Value &dt)
 Set absolute time of deadline associated with the message. More...
 
virtual ACE_Message_Blockclone (Message_Flags mask=0) const
 
virtual ACE_Message_Blockduplicate (void) const
 Return a "shallow" copy that increments our reference count by 1. More...
 
virtual ACE_Message_Blockrelease (void)
 
int copy (const char *buf, size_t n)
 
int copy (const char *buf)
 
int crunch (void)
 
void reset (void)
 
void access_allocators (ACE_Allocator *&allocator_strategy, ACE_Allocator *&data_block_allocator, ACE_Allocator *&message_block_allocator)
 
void reset_allocators (ACE_Allocator *allocator_strategy=0, ACE_Allocator *data_block_allocator=0, ACE_Allocator *message_block_allocator=0)
 
char * base (void) const
 Get message data. More...
 
void base (char *data, size_t size, Message_Flags=DONT_DELETE)
 Set message data (doesn't reallocate). More...
 
char * end (void) const
 Return a pointer to 1 past the end of the allocated data in a message. More...
 
char * mark (void) const
 
char * rd_ptr (void) const
 Get the read pointer. More...
 
void rd_ptr (char *ptr)
 Set the read pointer to ptr. More...
 
void rd_ptr (size_t n)
 Set the read pointer ahead n bytes. More...
 
char * wr_ptr (void) const
 Get the write pointer. More...
 
void wr_ptr (char *ptr)
 Set the write pointer to ptr. More...
 
void wr_ptr (size_t n)
 
ACE_Data_Blockdata_block (void) const
 
void data_block (ACE_Data_Block *)
 
ACE_Data_Blockreplace_data_block (ACE_Data_Block *)
 
ACE_Message_Blockcont (void) const
 Get the continuation field. More...
 
void cont (ACE_Message_Block *)
 Set the continuation field. More...
 
ACE_Message_Blocknext (void) const
 Get link to next message. More...
 
void next (ACE_Message_Block *)
 Set link to next message. More...
 
ACE_Message_Blockprev (void) const
 Get link to prev message. More...
 
void prev (ACE_Message_Block *)
 Set link to prev message. More...
 
ACE_Locklocking_strategy (void)
 Get the locking strategy. More...
 
ACE_Locklocking_strategy (ACE_Lock *)
 Set a new locking strategy and return the hold one. More...
 
int reference_count (void) const
 Get the current reference count. More...
 
void dump (void) const
 Dump the state of an object. More...
 
Message length and size operations

Message length is (wr_ptr - rd_ptr).

Message size is capacity of the message, including data outside the [rd_ptr,wr_ptr] range.

size_t length (void) const
 Get the length of the message. More...
 
void length (size_t n)
 Set the length of the message. More...
 
size_t total_length (void) const
 
size_t total_size (void) const
 
void total_size_and_length (size_t &mb_size, size_t &mb_length) const
 
size_t size (void) const
 
int size (size_t length)
 
size_t total_capacity (void) const
 
size_t capacity (void) const
 Get the number of allocated bytes in the top-level Message_Block. More...
 
size_t space (void) const
 

Static Public Member Functions

static ACE_Message_Blockduplicate (const ACE_Message_Block *mb)
 
static ACE_Message_Blockrelease (ACE_Message_Block *mb)
 

Public Attributes

 ACE_ALLOC_HOOK_DECLARE
 Declare the dynamic allocation hooks. More...
 

Protected Member Functions

 ACE_Message_Block (size_t size, ACE_Message_Type type, ACE_Message_Block *cont, const char *data, ACE_Allocator *allocator_strategy, ACE_Lock *locking_strategy, Message_Flags flags, unsigned long priority, const ACE_Time_Value &execution_time, const ACE_Time_Value &deadline_time, ACE_Data_Block *db, ACE_Allocator *data_block_allocator, ACE_Allocator *message_block_allocator)
 Perform the actual initialization. More...
 
int release_i (ACE_Lock *lock)
 
int init_i (size_t size, ACE_Message_Type type, ACE_Message_Block *cont, const char *data, ACE_Allocator *allocator_strategy, ACE_Lock *locking_strategy, Message_Flags flags, unsigned long priority, const ACE_Time_Value &execution_time, const ACE_Time_Value &deadline_time, ACE_Data_Block *db, ACE_Allocator *data_block_allocator, ACE_Allocator *message_block_allocator)
 Perform the actual initialization. More...
 

Protected Attributes

size_t rd_ptr_
 Pointer to beginning of next read. More...
 
size_t wr_ptr_
 Pointer to beginning of next write. More...
 
unsigned long priority_
 Priority of message. More...
 
ACE_Message_Blockcont_
 Pointer to next message block in the chain. More...
 
ACE_Message_Blocknext_
 Pointer to next message in the list. More...
 
ACE_Message_Blockprev_
 Pointer to previous message in the list. More...
 
ACE_Message_Block::Message_Flags flags_
 Misc flags (e.g., DONT_DELETE and USER_FLAGS). More...
 
ACE_Data_Blockdata_block_
 
ACE_Allocatormessage_block_allocator_
 

Private Member Functions

ACE_Message_Blockoperator= (const ACE_Message_Block &)
 
 ACE_Message_Block (const ACE_Message_Block &)
 

Friends

class ACE_Data_Block
 

Detailed Description

Stores messages for use throughout ACE (particularly in an ACE_Message_Queue).

An ACE_Message_Block is modeled after the message data structures used in System V STREAMS. Its purpose is to enable efficient manipulation of arbitrarily large messages without incurring much memory copying overhead. Here are the main characteristics of an ACE_Message_Block:

See Also
C++NPv1, section 4.2; APG, section 12.3.2.

Member Typedef Documentation

typedef unsigned long ACE_Message_Block::Message_Flags

Member Enumeration Documentation

anonymous enum
Enumerator
MB_DATA 

Undifferentiated data message.

MB_PROTO 

Undifferentiated protocol control.

MB_BREAK 

Line break (regular and priority)

MB_PASSFP 

Pass file pointer.

MB_EVENT 

Post an event to an event queue.

MB_SIG 

Generate process signal.

MB_IOCTL 

ioctl; set/get params

MB_SETOPTS 

Set various stream head options.

MB_IOCACK 

Acknowledge ioctl (high priority; go to head of queue)

MB_IOCNAK 

Negative ioctl acknowledge.

MB_PCPROTO 

Priority proto message.

MB_PCSIG 

Generate process signal.

MB_READ 

Generate read notification.

MB_FLUSH 

Flush your queues.

MB_STOP 

Stop transmission immediately.

MB_START 

Restart transmission after stop.

MB_HANGUP 

Line disconnect.

MB_ERROR 

Fatal error used to set u.u_error.

MB_PCEVENT 

Post an event to an event queue.

MB_NORMAL 

Normal priority message mask.

MB_PRIORITY 

High priority control message mask.

MB_USER 

User-defined message mask.

anonymous enum
Enumerator
DONT_DELETE 

Don't delete the data on exit since we don't own it.

USER_FLAGS 

user defined flags start here

Constructor & Destructor Documentation

ACE_Message_Block::ACE_Message_Block ( ACE_Allocator message_block_allocator = 0)

Create an empty message.

ACE_Message_Block::ACE_Message_Block ( ACE_Data_Block data_block,
ACE_Message_Block::Message_Flags  flags = 0,
ACE_Allocator message_block_allocator = 0 
)

Create an ACE_Message_Block that owns the specified ACE_Data_Block without copying it. If the flags is set to DONT_DELETE we don't delete the ACE_Data_Block. It is left to the client's responsibility to take care of the memory allocated for the data_block

ACE_Message_Block::ACE_Message_Block ( const char *  data,
size_t  size = 0,
unsigned long  priority = ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY 
)

Create an ACE_Message_Block that refers to data without copying it. The data memory will not be freed when this block is destroyed; memory management of data is left to the caller. Note that the size of the new ACE_Message_Block will be size, but the length will be 0 until the write pointer is changed.

ACE_Message_Block::ACE_Message_Block ( size_t  size,
ACE_Message_Type  type = MB_DATA,
ACE_Message_Block cont = 0,
const char *  data = 0,
ACE_Allocator allocator_strategy = 0,
ACE_Lock locking_strategy = 0,
unsigned long  priority = ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY,
const ACE_Time_Value execution_time = ACE_Time_Value::zero,
const ACE_Time_Value deadline_time = ACE_Time_Value::max_time,
ACE_Allocator data_block_allocator = 0,
ACE_Allocator message_block_allocator = 0 
)

Create an initialized message of type type containing size bytes. The cont argument initializes the continuation field in the ACE_Message_Block. If data == 0 then this block allocates and owns the block's memory, using allocator to get the data if it's non-0. If data != 0 then this block refers to that memory until this this block ceases to exist; this object will not free data on destruction. If locking_strategy is non-0 then this is used to protect regions of code that access shared state (e.g., reference counting) from race conditions. Note that the size of the ACE_Message_Block will be size, but the length will be 0 until the write pointer is set. The data_block_allocator is used to allocate the data blocks while the allocator_strategy is used to allocate the buffers contained by those. The message_block_allocator is used to allocate new ACE_Message_Block objects when the duplicate() method is called. If a message_block_allocator is given, this ACE_Message_Block and future ACE_Message_Block objects created by duplicate() will be freed using this allocator when they are released.

Note
If you use this allocator, the ACE_Message_Block you created should have been created using this allocator because it will be released to the same allocator.
ACE_Message_Block::ACE_Message_Block ( const ACE_Message_Block mb,
size_t  align 
)

A copy constructor. This constructor is a bit different. If the incoming Message Block has a data block from the stack this constructor does a deep copy ie. allocates a new data block on the heap and does a copy of the data from the incoming message block. As a final note, the alignment information is used to align the data block if it is created afresh. If the incoming mb has a data block has a data block allocated from the heap, then this constructor just duplicates (ie. a shallow copy) the data block of the incoming mb.

ACE_Message_Block::~ACE_Message_Block ( void  )
virtual

Delete all the resources held in the message.

Note
Note that release() is designed to release the continuation chain; the destructor is not. See release() for details.
ACE_Message_Block::ACE_Message_Block ( size_t  size,
ACE_Message_Type  type,
ACE_Message_Block cont,
const char *  data,
ACE_Allocator allocator_strategy,
ACE_Lock locking_strategy,
Message_Flags  flags,
unsigned long  priority,
const ACE_Time_Value execution_time,
const ACE_Time_Value deadline_time,
ACE_Data_Block db,
ACE_Allocator data_block_allocator,
ACE_Allocator message_block_allocator 
)
protected

Perform the actual initialization.

ACE_Message_Block::ACE_Message_Block ( const ACE_Message_Block )
private

Member Function Documentation

void ACE_Message_Block::access_allocators ( ACE_Allocator *&  allocator_strategy,
ACE_Allocator *&  data_block_allocator,
ACE_Allocator *&  message_block_allocator 
)
inline

Access all the allocators in the message block.

Todo:
Not sure whether we would need finer control while trying to access allocators ie. a method for every allocator.

This method returns the allocators only from the first message block in the chain.

Parameters
allocator_strategyStrategy used to allocate the underlying buffer
data_block_allocatorStrategy used to allocate the underlying data block
message_block_allocatorStrategy used to allocate the message block
char * ACE_Message_Block::base ( void  ) const
inline

Get message data.

void ACE_Message_Block::base ( char *  data,
size_t  size,
Message_Flags  msg_flags = DONT_DELETE 
)
inline

Set message data (doesn't reallocate).

size_t ACE_Message_Block::capacity ( void  ) const
inline

Get the number of allocated bytes in the top-level Message_Block.

ACE_Message_Block * ACE_Message_Block::clone ( Message_Flags  mask = 0) const
virtual

Return an exact "deep copy" of the message, i.e., create fresh new copies of all the Data_Blocks and continuations.

ACE_Message_Block::Message_Flags ACE_Message_Block::clr_flags ( ACE_Message_Block::Message_Flags  less_flags)
inline

Clear the message flag bits specified in less_flags and return the new value.

ACE_Message_Block::Message_Flags ACE_Message_Block::clr_self_flags ( ACE_Message_Block::Message_Flags  less_flags)
inline

Clear the message flag bits specified in less_flags and return the new value.

ACE_Message_Block * ACE_Message_Block::cont ( void  ) const
inline

Get the continuation field.

void ACE_Message_Block::cont ( ACE_Message_Block cont_msg)
inline

Set the continuation field.

int ACE_Message_Block::copy ( const char *  buf,
size_t  n 
)

Copies data into this ACE_Message_Block. Data is copied into the block starting at the current write pointer.

Parameters
bufPointer to the buffer to copy from.
nThe number of bytes to copy.
Return values
0on success; the write pointer is advanced by
  • n.
-1if the amount of free space following the write pointer in the block is less than
  • n. Free space can be checked by calling space().
int ACE_Message_Block::copy ( const char *  buf)

Copies a 0-terminated character string into this ACE_Message_Block. The string is copied into the block starting at the current write pointer. The 0-terminator is included in the copied data.

Parameters
bufPointer to the character string to copy from.
Return values
0on success; the write pointer is advanced by the string's length, including the 0 terminator.
-1if the amount of free space following the write pointer in the block is less than required to hold the entire string. Free space can be checked by calling space().
int ACE_Message_Block::crunch ( void  )

Normalizes data in the top-level Message_Block to align with the base, i.e., it "shifts" the data pointed to by <rd_ptr> down to the <base> and then readjusts <rd_ptr> to point to <base> and <wr_ptr> to point to <base> + the length of the moved data. Returns -1 and does nothing if the <rd_ptr> is > <wr_ptr>, else 0 on success.

ACE_Data_Block * ACE_Message_Block::data_block ( void  ) const
inline

Get a pointer to the data block. Note that the ACE_Message_Block still references the block; this call does not change the reference count.

void ACE_Message_Block::data_block ( ACE_Data_Block db)

Set a new data block pointer. The original ACE_Data_Block is released as a result of this call. If you need to keep the original block, call <replace_data_block> instead. Upon return, this ACE_Message_Block holds a pointer to the new ACE_Data_Block, taking over the reference you held on it prior to the call.

void ACE_Message_Block::dump ( void  ) const

Dump the state of an object.

ACE_Message_Block * ACE_Message_Block::duplicate ( void  ) const
virtual

Return a "shallow" copy that increments our reference count by 1.

ACE_Message_Block * ACE_Message_Block::duplicate ( const ACE_Message_Block mb)
static

Return a "shallow" copy that increments our reference count by 1. This is similar to CORBA's _duplicate() method, which is useful if you want to eliminate lots of checks for NULL mb pointers before calling _duplicate() on them.

char * ACE_Message_Block::end ( void  ) const
inline

Return a pointer to 1 past the end of the allocated data in a message.

ACE_Message_Block::Message_Flags ACE_Message_Block::flags ( void  ) const
inline

Get the current message flags.

int ACE_Message_Block::init ( const char *  data,
size_t  size = 0 
)

Create a Message Block that assumes it has ownership of data, but in reality it doesn't (i.e., cannot delete it since it didn't malloc it!). Note that the size of the Message_Block will be size, but the length will be 0 until <wr_ptr> is set.

int ACE_Message_Block::init ( size_t  size,
ACE_Message_Type  type = MB_DATA,
ACE_Message_Block cont = 0,
const char *  data = 0,
ACE_Allocator allocator_strategy = 0,
ACE_Lock locking_strategy = 0,
unsigned long  priority = ACE_DEFAULT_MESSAGE_BLOCK_PRIORITY,
const ACE_Time_Value execution_time = ACE_Time_Value::zero,
const ACE_Time_Value deadline_time = ACE_Time_Value::max_time,
ACE_Allocator data_block_allocator = 0,
ACE_Allocator message_block_allocator = 0 
)

Create an initialized message of type type containing size bytes. The cont argument initializes the continuation field in the Message_Block. If data == 0 then we create and own the data, using allocator_strategy to get the data if it's non-0. If data != 0 we assume that we have ownership of the data till this object ceases to exist (and don't delete it during destruction). If locking_strategy is non-0 then this is used to protect regions of code that access shared state (e.g., reference counting) from race conditions. Note that the size of the Message_Block will be size, but the length will be 0 until <wr_ptr> is set. The data_block_allocator is use to allocate the data blocks while the allocator_strategy is used to allocate the buffers contained by those.

int ACE_Message_Block::init_i ( size_t  size,
ACE_Message_Type  type,
ACE_Message_Block cont,
const char *  data,
ACE_Allocator allocator_strategy,
ACE_Lock locking_strategy,
Message_Flags  flags,
unsigned long  priority,
const ACE_Time_Value execution_time,
const ACE_Time_Value deadline_time,
ACE_Data_Block db,
ACE_Allocator data_block_allocator,
ACE_Allocator message_block_allocator 
)
protected

Perform the actual initialization.

int ACE_Message_Block::is_data_msg ( void  ) const
inline

Find out what type of message this is.

size_t ACE_Message_Block::length ( void  ) const
inline

Get the length of the message.

void ACE_Message_Block::length ( size_t  n)
inline

Set the length of the message.

ACE_Lock * ACE_Message_Block::locking_strategy ( void  )
inline

Get the locking strategy.

ACE_Lock * ACE_Message_Block::locking_strategy ( ACE_Lock nls)
inline

Set a new locking strategy and return the hold one.

char * ACE_Message_Block::mark ( void  ) const
inline

Return a pointer to 1 past the end of the allotted data in a message. Allotted data may be less than allocated data if a value smaller than capacity() to is passed to size().

ACE_Message_Block::ACE_Message_Type ACE_Message_Block::msg_class ( void  ) const
inline

Find out what class of message this is (there are two classes, normal messages and high-priority messages).

const ACE_Time_Value & ACE_Message_Block::msg_deadline_time ( void  ) const
inline

Get absolute time of deadline associated with the message.

void ACE_Message_Block::msg_deadline_time ( const ACE_Time_Value dt)
inline

Set absolute time of deadline associated with the message.

const ACE_Time_Value & ACE_Message_Block::msg_execution_time ( void  ) const
inline

Get execution time associated with the message.

void ACE_Message_Block::msg_execution_time ( const ACE_Time_Value et)
inline

Set execution time associated with the message.

unsigned long ACE_Message_Block::msg_priority ( void  ) const
inline

Get priority of the message.

void ACE_Message_Block::msg_priority ( unsigned long  priority)
inline

Set priority of the message.

ACE_Message_Block::ACE_Message_Type ACE_Message_Block::msg_type ( void  ) const
inline

Get type of the message.

void ACE_Message_Block::msg_type ( ACE_Message_Block::ACE_Message_Type  t)
inline

Set type of the message.

ACE_Message_Block * ACE_Message_Block::next ( void  ) const
inline

Get link to next message.

void ACE_Message_Block::next ( ACE_Message_Block next_msg)
inline

Set link to next message.

ACE_Message_Block & ACE_Message_Block::operator= ( const ACE_Message_Block )
private
ACE_Message_Block * ACE_Message_Block::prev ( void  ) const
inline

Get link to prev message.

void ACE_Message_Block::prev ( ACE_Message_Block next_msg)
inline

Set link to prev message.

char * ACE_Message_Block::rd_ptr ( void  ) const
inline

Get the read pointer.

void ACE_Message_Block::rd_ptr ( char *  ptr)
inline

Set the read pointer to ptr.

void ACE_Message_Block::rd_ptr ( size_t  n)
inline

Set the read pointer ahead n bytes.

int ACE_Message_Block::reference_count ( void  ) const
inline

Get the current reference count.

ACE_Message_Block * ACE_Message_Block::release ( void  )
virtual

Decrease the shared ACE_Data_Block's reference count by 1. If the ACE_Data_Block's reference count goes to 0, it is deleted. In all cases, this ACE_Message_Block is deleted - it must have come from the heap, or there will be trouble.

release() is designed to release the continuation chain; the destructor is not. If we make the destructor release the continuation chain by calling release() or delete on the message blocks in the continuation chain, the following code will not work since the message block in the continuation chain is not off the heap:

ACE_Message_Block mb1 (1024); ACE_Message_Block mb2 (1024);

mb1.cont (&mb2);

And hence, call release() on a dynamically allocated message block. This will release all the message blocks in the continuation chain. If you call delete or let the message block fall off the stack, cleanup of the message blocks in the continuation chain becomes the responsibility of the user.

Return values
0,always,andthe object this method was invoked on is no longer valid.
ACE_Message_Block * ACE_Message_Block::release ( ACE_Message_Block mb)
static

This behaves like the non-static method release(), except that it checks if mb is 0. This is similar to CORBA::release(), which is useful if you want to eliminate lots of checks for NULL pointers before calling release() on them. Returns mb.

int ACE_Message_Block::release_i ( ACE_Lock lock)
protected

Internal release implementation Returns 1 if the data block has to be destroyed.

ACE_Data_Block * ACE_Message_Block::replace_data_block ( ACE_Data_Block db)
inline

Set a new data block pointer. A pointer to the original ACE_Data_Block is returned, and not released (as it is with <data_block>).

void ACE_Message_Block::reset ( void  )
inline

Resets the Message Block data to contain nothing, i.e., sets the read and write pointers to align with the base.

void ACE_Message_Block::reset_allocators ( ACE_Allocator allocator_strategy = 0,
ACE_Allocator data_block_allocator = 0,
ACE_Allocator message_block_allocator = 0 
)
inline

Reset all the allocators in the message block.

Todo:
Not sure whether we would need finer control while trying to reset allocators ie. a method for every allocator.

This method resets the allocators in all the message blocks in the chain.

ACE_Message_Block::Message_Flags ACE_Message_Block::self_flags ( void  ) const
inline

Get the current message flags.

ACE_Message_Block::Message_Flags ACE_Message_Block::set_flags ( ACE_Message_Block::Message_Flags  more_flags)
inline

Bitwise-or the more_flags into the existing message flags and return the new value.

ACE_Message_Block::Message_Flags ACE_Message_Block::set_self_flags ( ACE_Message_Block::Message_Flags  more_flags)
inline

Bitwise-or the more_flags into the existing message flags and return the new value.

Todo:
I think the following set of methods could not be used at all. May be they are useless. Let us have it so that we don't mess up memory management of the Message_Block. Somebody correct me if I am totally totally wrong..
size_t ACE_Message_Block::size ( void  ) const
inline

Get the number of bytes in the top-level Message_Block (i.e., does not consider the bytes in chained Message_Blocks).

int ACE_Message_Block::size ( size_t  length)

Set the number of bytes in the top-level Message_Block, reallocating space if necessary. However, the rd_ptr_ and wr_ptr_ remain at the original offsets into the buffer, even if it is reallocated. Returns 0 if successful, else -1.

size_t ACE_Message_Block::space ( void  ) const
inline

Get the number of bytes available after the <wr_ptr_> in the top-level Message_Block.

size_t ACE_Message_Block::total_capacity ( void  ) const

Get the number of allocated bytes in all Message_Block, including chained Message_Blocks.

size_t ACE_Message_Block::total_length ( void  ) const

Get the length of the Message_Blocks, including chained Message_Blocks.

size_t ACE_Message_Block::total_size ( void  ) const

Get the total number of bytes in all Message_Blocks, including chained Message_Blocks.

void ACE_Message_Block::total_size_and_length ( size_t &  mb_size,
size_t &  mb_length 
) const

Get the total number of bytes and total length in all Message_Blocks, including chained Message_Blocks.

char * ACE_Message_Block::wr_ptr ( void  ) const
inline

Get the write pointer.

void ACE_Message_Block::wr_ptr ( char *  ptr)
inline

Set the write pointer to ptr.

void ACE_Message_Block::wr_ptr ( size_t  n)
inline

Set the write pointer ahead n bytes. This is used to compute the <length> of a message.

Friends And Related Function Documentation

friend class ACE_Data_Block
friend

Member Data Documentation

ACE_Message_Block::ACE_ALLOC_HOOK_DECLARE

Declare the dynamic allocation hooks.

ACE_Message_Block* ACE_Message_Block::cont_
protected

Pointer to next message block in the chain.

ACE_Data_Block* ACE_Message_Block::data_block_
protected

Pointer to the reference counted data structure that contains the actual memory buffer.

ACE_Message_Block::Message_Flags ACE_Message_Block::flags_
protected

Misc flags (e.g., DONT_DELETE and USER_FLAGS).

ACE_Allocator* ACE_Message_Block::message_block_allocator_
protected

The allocator used to destroy ourselves when release is called and create new message blocks on duplicate.

ACE_Message_Block* ACE_Message_Block::next_
protected

Pointer to next message in the list.

ACE_Message_Block* ACE_Message_Block::prev_
protected

Pointer to previous message in the list.

unsigned long ACE_Message_Block::priority_
protected

Priority of message.

size_t ACE_Message_Block::rd_ptr_
protected

Pointer to beginning of next read.

size_t ACE_Message_Block::wr_ptr_
protected

Pointer to beginning of next write.


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