t_cancel.h File Reference

TM :: CANCEL handling. More...

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Defines
#define	BUSY_BUFFER   ((char *)-1)
	A buffer is empty but cannot be used by anyone else.
Typedefs
typedef unsigned int(*	tuaccancel_f )(str *headers, str *body, unsigned int cancelledIdx, unsigned int cancelledLabel, transaction_cb cb, void *cbp)
Functions
char *	build_cancel (struct cell *Trans, unsigned int branch, unsigned int *len)
void	cancel_branch (struct cell *t, int branch)
void	cancel_uacs (struct cell *t, branch_bm_t cancel_bm)
	cancel branches scheduled for deletion
static short	should_cancel_branch (struct cell *t, int b)
unsigned int	t_uac_cancel (str *headers, str *body, unsigned int cancelledIdx, unsigned int cancelledLabel, transaction_cb cb, void *cbp)
	This function cancels a previously created local invite transaction.
int	unixsock_uac_cancel (str *msg)
void	which_cancel (struct cell *t, branch_bm_t *cancel_bm)
	Determine which branches should be canceled.

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Detailed Description

TM :: CANCEL handling.

• Module: TM :: Stateful transaction handling

Definition in file t_cancel.h.

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Define Documentation

#define BUSY_BUFFER   ((char *)-1)

A buffer is empty but cannot be used by anyone else.

particularly, we use this value in the buffer pointer in local_buffer to tell "a process is already scheduled to generate a CANCEL, other processes are not supposed to" (which might happen if for example in a three-branch forking, two 200 would enter separate processes and compete for canceling the third branch); note that to really avoid race conditions, the value must be set in REPLY_LOCK

Definition at line 48 of file t_cancel.h.

Referenced by cancel_branch(), free_cell(), should_cancel_branch(), and t_cancel_branches().

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Typedef Documentation

typedef unsigned int(* tuaccancel_f)(str *headers, str *body, unsigned int cancelledIdx, unsigned int cancelledLabel, transaction_cb cb, void *cbp)

Definition at line 59 of file t_cancel.h.

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Function Documentation

char* build_cancel	(	struct cell *	Trans,
		unsigned int	branch,
		unsigned int *	len
	)

Definition at line 124 of file t_cancel.c.

References build_local(), CANCEL, CANCEL_LEN, and cell::to.

Referenced by cancel_branch().

void cancel_branch	(	struct cell *	t,
		int	branch
	)

Definition at line 80 of file t_cancel.c.

References retr_buf::activ_type, retr_buf::branch, retr_buf::buffer, build_cancel(), BUSY_BUFFER, retr_buf::dst, has_tran_tmcbs, _str::len, len, LM_CRIT, LM_DBG, LM_ERR, ua_client::local_cancel, ua_server::request, ua_client::request, run_trans_callbacks(), _str::s, SEND_BUFFER, set_extra_tmcb_params(), start_retr(), TMCB_REQUEST_BUILT, TYPE_LOCAL_CANCEL, cell::uac, and cell::uas.

Referenced by cancel_uacs(), fake_reply(), and reply_received().

void cancel_uacs	(	struct cell *	t,
		branch_bm_t	cancel_bm
	)

cancel branches scheduled for deletion

Definition at line 69 of file t_cancel.c.

References cancel_branch(), and cell::nr_of_outgoings.

Referenced by _reply_light(), cancel_invite(), local_reply(), mi_tm_cancel(), relay_reply(), reply_received(), and t_cancel_branches().

static short should_cancel_branch	(	struct cell *	t,
		int	b
	)			[inline, static]

Definition at line 66 of file t_cancel.h.

References retr_buf::buffer, BUSY_BUFFER, ua_client::flags, ua_client::last_received, ua_client::local_cancel, NULL, _str::s, T_UAC_TO_CANCEL_FLAG, and cell::uac.

Referenced by fake_reply(), and which_cancel().

unsigned int t_uac_cancel	(	str *	headers,
		str *	body,
		unsigned int	cancelled_hashIdx,
		unsigned int	cancelled_label,
		transaction_cb	cb,
		void *	cbp
	)

This function cancels a previously created local invite transaction.

The cancel parameter should NOT have any via (CANCEL is hop-by-hop).

Returns:

0 if error

>0 if OK (returns the LABEL of the cancel).

Definition at line 140 of file t_cancel.c.

References buf, retr_buf::buffer, build_cell(), build_uac_cancel(), retr_buf::dst, cell::flags, free_cell(), cell::hash_index, insert_into_hash_table_unsafe(), insert_tmcb(), is_local, cell::label, ua_client::last_received, _str::len, len, LM_ERR, LM_WARN, LOCK_HASH, cell::method, cell::nr_of_outgoings, dest_info::proto, dest_info::proto_reserved1, remove_from_hash_table_unsafe(), ua_client::request, reset_avps(), _str::s, SEND_BUFFER, dest_info::send_sock, start_retr(), T_IS_LOCAL_FLAG, t_lookup_ident(), cell::tmcb_hl, TMCB_LOCAL_COMPLETED, TMCB_RESPONSE_IN, dest_info::to, cell::uac, and UNLOCK_HASH.

Referenced by load_tm().

int unixsock_uac_cancel

(

str *

msg

)

void which_cancel	(	struct cell *	t,
		branch_bm_t *	cancel_bm
	)

Determine which branches should be canceled.

Do it only from within REPLY_LOCK, otherwise collisions could occur (e.g., two 200 for two branches processed by two processes might concurrently try to generate a CANCEL for the third branch, resulting in race conditions during writing to cancel buffer

Definition at line 56 of file t_cancel.c.

References cell::first_branch, and should_cancel_branch().

Referenced by _reply_light(), cancel_invite(), local_reply(), t_cancel_branches(), and t_should_relay_response().