net::impl::Callstack< Key, Value > Class Template Reference

callstack of a thread. More...

#include <callstack.h>

Classes
class	Context
class	Iterator
	forward-iterator over stack frames. More...

Public Types
using	value_type = Context *
using	iterator = Iterator
using	const_iterator = Iterator

Static Public Member Functions
static constexpr Value *	contains (const Key *k)
	check if a callstack contains a pointer already. More...
static Iterator	begin ()
	begin() iterator More...
static Iterator	end ()
	end() iterator More...

Static Private Attributes
static thread_local Context *	stack_top_

Detailed Description

template<class Key, class Value = unsigned char>
class net::impl::Callstack< Key, Value >

callstack of a thread.

use-cases:

• track debuginfo of call chains
• check if the function calls itself

Each new stackframe links to the previous stackframe and sets itself as stacktop. As callstacks are per-thread, no locking is needed.

Usage

struct Frame {
  const char *filename;
  int line;
  const char *func;
 
  Frame(const char *f, int l, const char *fun):
    filename(f), line(l), func(fun) {}
};
void a() {
  Frame frame(__FILE__, __LINE__, __func__);
  Callstack<Frame>::Context stackframe(&frame);
}
 
void b() {
  // store a frame on the functions stack
  Frame frame(__FILE__, __LINE__, __func__);
  // link the 'frame' to the callstack
  Callstack<Frame>::Context stackframe(&frame);
 
  a();
}

Template Parameters

Key	key-type
Value	value-type to assign to the key

Member Typedef Documentation

const_iterator

template<class Key , class Value = unsigned char>

using net::impl::Callstack< Key, Value >::const_iterator = Iterator

iterator

template<class Key , class Value = unsigned char>

using net::impl::Callstack< Key, Value >::iterator = Iterator

value_type

template<class Key , class Value = unsigned char>

using net::impl::Callstack< Key, Value >::value_type = Context *

Member Function Documentation

begin()

template<class Key , class Value = unsigned char>

static Iterator net::impl::Callstack< Key, Value >::begin ( )

inlinestatic

begin() iterator

contains()

template<class Key , class Value = unsigned char>

static constexpr Value * net::impl::Callstack< Key, Value >::contains ( const Key *  k )

inlinestaticconstexpr

check if a callstack contains a pointer already.

walks the stack from the top the last element and checks if a frames key makes k

Parameters

k	key to search for in the callstack

Returns

stored value if key is found

Return values

nullptr

if not found.

end()

template<class Key , class Value = unsigned char>

static Iterator net::impl::Callstack< Key, Value >::end ( )

inlinestatic

end() iterator

Member Data Documentation

stack_top_

template<class Key , class Value >

thread_local Callstack< Key, Value >::Context * net::impl::Callstack< Key, Value >::stack_top_

staticprivate

Initial value:

=
        nullptr

---

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

• router/src/harness/include/mysql/harness/net_ts/impl/callstack.h