graphlab::safe_circular_char_buffer Class Reference

#include <graphlab/util/safe_circular_char_buffer.hpp>

List of all members.

Public Member Functions
	safe_circular_char_buffer (std::streamsize bufsize=10485760)
void	stop_reader ()
bool	empty () const
bool	is_done () const
bool	reader_is_blocked () const
std::streamsize	size () const
std::streamsize	free_space () const
std::streamsize	reserved_size () const
std::streamsize	write (const char *c, std::streamsize clen)
std::streamsize	write_unsafe (const char *c, std::streamsize clen)
std::streamsize	introspective_read (char *&s, std::streamsize clen)
std::streamsize	blocking_introspective_read (char *&s, std::streamsize clen)
void	advance_head (const std::streamsize advance_len)
void	begin_critical_section ()
void	end_critical_section ()
void	end_critical_section_with_signal ()

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Detailed Description

A non-resizing circular char buffer with thread-safe write operations and a single reader

Definition at line 37 of file safe_circular_char_buffer.hpp.

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Member Function Documentation

void graphlab::safe_circular_char_buffer::begin_critical_section ( )

inline

When begin critical section returns, it is guaranteed that no other writer will be touching the tail of the queue

Definition at line 124 of file safe_circular_char_buffer.hpp.

std::streamsize graphlab::safe_circular_char_buffer::blocking_introspective_read	(	char *&	s,
		std::streamsize	clen
	)

Same as introspective read. But blocks until there is something to read This function does not acquire a critical section.

Definition at line 136 of file safe_circular_char_buffer.cpp.

bool graphlab::safe_circular_char_buffer::empty

(

)

const

Determine if the buffer is empty

Definition at line 48 of file safe_circular_char_buffer.cpp.

void graphlab::safe_circular_char_buffer::end_critical_section ( )

inline

Releases a critical section acquired by begin_critical_section

Definition at line 129 of file safe_circular_char_buffer.hpp.

void graphlab::safe_circular_char_buffer::end_critical_section_with_signal ( )

inline

Releases a critical section acquired by begin_critical_section, and signals the reader to begin reading if the reader is blocked

Definition at line 135 of file safe_circular_char_buffer.hpp.

std::streamsize graphlab::safe_circular_char_buffer::free_space

(

)

const

Get the amount of free space reamining in the buffer

Definition at line 60 of file safe_circular_char_buffer.cpp.

std::streamsize graphlab::safe_circular_char_buffer::introspective_read	(	char *&	s,
		std::streamsize	clen
	)

Returns a pointer (through s) and a length of the read. This pointer is a direct pointer into the internal buffer of this datastructure. The pointer is valid as long as no other operations are performed on this structure. The length of the introspective_read may be less than the number of bytes requested. Multiple calls to introspective_read may be necessary to read all data in the buffer. If the function returns 0, the buffer is empty.

No locks are acquired on this call.

Definition at line 109 of file safe_circular_char_buffer.cpp.

std::streamsize graphlab::safe_circular_char_buffer::reserved_size ( ) const

inline

Gets the size of the buffer.

Note:

: The useable space is reserved_size() - 1

Definition at line 73 of file safe_circular_char_buffer.hpp.

std::streamsize graphlab::safe_circular_char_buffer::size

(

)

const

Get the total contents currently stored in the buffer.

Definition at line 52 of file safe_circular_char_buffer.cpp.

void graphlab::safe_circular_char_buffer::stop_reader

(

)

Stops the buffer and signals any blocking calls.

Definition at line 40 of file safe_circular_char_buffer.cpp.

std::streamsize graphlab::safe_circular_char_buffer::write	(	const char *	c,
		std::streamsize	clen
	)

Returns 0 if the write doesn't fit

This function acquires the critical section to perform the write

Definition at line 65 of file safe_circular_char_buffer.cpp.

std::streamsize graphlab::safe_circular_char_buffer::write_unsafe	(	const char *	c,
		std::streamsize	clen
	)

Returns 0 if the write doesn't fit

This does the same as write(), but does not acquire the critical section. The caller should ensure safety

Definition at line 76 of file safe_circular_char_buffer.cpp.

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

• graphlab/util/safe_circular_char_buffer.hpp
• graphlab/util/safe_circular_char_buffer.cpp