Error

---

This group discusses the functions that provide error management for projects.

The Eina error module provides a way to manage errors in a simple but powerful way in libraries and modules. It is also used in Eina itself. An extension to libC's errno and strerror() facilities, this is extensible and recommended for other libraries and applications as well.

While libC's errno is fixed, Eina_Error can be extended by libraries and applications with domain-specific codes and associated error messages. All errno.h codes are usable seamlessly with Eina_Error. The constants defined in errno.h will have messages as reported by strerror() in eina_error_msg_get()

Success (no-error) condition is reported with Eina_Error 0 (EINA_ERROR_NO_ERROR).

A simple example of how to use this can be seen here.

Functions
Eina_Error	eina_error_msg_register (const char *msg)
	Registers a new error type.
Eina_Error	eina_error_msg_static_register (const char *msg)
	Registers a new error type, statically allocated message.
Eina_Bool	eina_error_msg_modify (Eina_Error error, const char *msg)
	Changes the message of an already registered message.
Eina_Error	eina_error_get (void)
	Returns the last set error.
void	eina_error_set (Eina_Error err)
	Sets the last error.
const char *	eina_error_msg_get (Eina_Error error)
	Returns the description of the given error number.
Eina_Error	eina_error_find (const char *msg)
	Finds the Eina_Error corresponding to a message string.
Typedefs
typedef int	Eina_Error
	The integer type containing the error type.
typedef Eina_Bool	Eina_Success_Flag
	A flag indicating a function completed succesfully.
Defines
#define	EINA_ERROR_NO_ERROR   ((Eina_Error)0)
	No error reported.

---

Define Documentation

#define EINA_ERROR_NO_ERROR   ((Eina_Error)0)

No error reported.

This is a convenience macro for people that are extra verbose, same as "0".

---

Typedef Documentation

Eina_Error

The integer type containing the error type.

Errors are registered with eina_error_msg_register(), eina_error_msg_static_register() or those inherited from the system's errno.h such as ENOMEM.

Eina_Success_Flag

A flag indicating a function completed succesfully.

Errors are reported with a EINA_FALSE value for Eina_Success_Flag return and success with a EINA_TRUE.

---

Function Documentation

Eina_Error eina_error_find

(

const char *

msg

)

Finds the Eina_Error corresponding to a message string.

This function attempts to match msg with its corresponding Eina_Error value. If no such value is found, 0 is returned.

Parameters:

[in]

msg

The error message string to match (NOT NULL)

Returns:

The Eina_Error matching msg, otherwise 0 on failure

Note:

this function only works for explicitly registered errors such as the messages given to eina_error_msg_register(), eina_error_msg_static_register() or modified with eina_error_msg_modify().

Since :

3.0

Eina_Error eina_error_get

(

void

)

Returns the last set error.

This function returns the last error set by eina_error_set(). The description of the message is returned by eina_error_msg_get().

Returns:

The last error or 0 (EINA_ERROR_NO_ERROR).

Note:

This function is thread safe

Since (EFL) :

1.10, but slower to use.

Since :

3.0f(2.3.1)

Examples:

eina_error_01.c.

const char* eina_error_msg_get

(

Eina_Error

error

)

Returns the description of the given error number.

This function returns the description of an error that has been registered by eina_error_msg_register(). If an incorrect error is given, then NULL is returned.

Parameters:

[in]

error

The error number

Returns:

The description of the error

Since :

3.0f(2.3.1)

Examples:

eina_error_01.c.

Eina_Bool eina_error_msg_modify	(	Eina_Error	error,
		const char *	msg
	)

Changes the message of an already registered message.

This function modifies the message associated with error and changes it to msg. If the error is previously registered by eina_error_msg_static_register then the string is not duplicated, otherwise the previous message is unref'ed and msg is copied.

Parameters:

[in]	error	The Eina_Error to change the message of
[in]	msg	The description of the error This string is duplicated only if the error is registered with eina_error_msg_register, otherwise it must remain intact for the duration.

Returns:

EINA_TRUE if successful, otherwise EINA_FALSE on error

Note:

It is not possible to modify messages that exist in libC's errno.h, such as ENOMEM or EBADF.

See also:

eina_error_msg_register()

Since :

3.0f(2.3.1)

Eina_Error eina_error_msg_register

(

const char *

msg

)

Registers a new error type.

This function stores the error message described by msg in a list. The returned value is a unique identifier greater than or equal to 1. The description can be retrieved later by passing the returned value to eina_error_msg_get().

Parameters:

[in]

msg

The description of the error It is duplicated using eina_stringshare_add().

Returns:

The unique number identifier for this error

Note:

There is no need to register messages that exist in libC's errno.h, such as ENOMEM or EBADF.

See also:

eina_error_msg_static_register()

Since :

3.0f(2.3.1)

Eina_Error eina_error_msg_static_register

(

const char *

msg

)

Registers a new error type, statically allocated message.

This function stores the error message described by msg in a list. The returned value is a unique identifier greater than or equal to 1. The description can be retrieved later by passing the returned value to eina_error_msg_get().

Parameters:

[in]

msg

The description of the error This string is not duplicated and thus the given pointer should live during the usage of eina_error.

Returns:

The unique number identifier for this error

Note:

There is no need to register messages that exist in libC's errno.h, such as ENOMEM or EBADF.

See also:

eina_error_msg_register()

Since :

3.0f(2.3.1)

Examples:

eina_error_01.c.

void eina_error_set

(

Eina_Error

err

)

Sets the last error.

This function sets the last error identifier. The last error can be retrieved by eina_error_get().

Parameters:

[in]

err

The error identifier

Note:

This is also used to clear previous errors, in which case err should be 0 (EINA_ERROR_NO_ERROR).

This function is thread safe

Since (EFL) :

1.10, but slower to use.

Since :

3.0f(2.3.1)

Examples:

eina_error_01.c.

---

Variable Documentation

EINA_ERROR_OUT_OF_MEMORY

The error identifier corresponding to lack of memory.

Since :

3.0f(2.3.1)

Deprecated:

since 1.19, same as ENOMEM from errno.h