> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs-staging.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# AR Osal Servreg

> Defines public APIs for service location, notification and state registration.

**Header:** `ar_osal/api/ar_osal_servreg.h`

## Structures

### `ar_osal_servreg_entry_type`

Struct representing the name of the service or domain and the instance id.

**Members**

<ParamField path="name" type="char_t">
  Name of the service or domain.
</ParamField>

<ParamField path="instance_id" type="uint32_t" />

### `ar_osal_servreg_state_notify_payload`

servreg service state notify callback payload.

**Members**

<ParamField path="service" type="ar_osal_servreg_entry_type" />

<ParamField path="domain" type="ar_osal_servreg_entry_type" />

<ParamField path="service_state" type="ar_osal_service_state_type" />

## Functions

### `ar_osal_servreg_init`

ar\_osal\_servreg\_init Initialize servreg interface.

```cpp theme={null}
int32_t ar_osal_servreg_init(void)
```

**Returns**

0  Success Nonzero  Failure

### `ar_osal_servreg_deinit`

ar\_osal\_servreg\_deinit Uninitialize servreg interface.

```cpp theme={null}
int32_t ar_osal_servreg_deinit(void)
```

**Returns**

0  Success Nonzero  Failure

### `ar_osal_servreg_get_domainlist`

ar\_osal\_servreg\_get\_domainlist Client to call this API to get a list of domains(msm/domain/subdomain) on which a given service(provider/service) is supported.

```cpp theme={null}
int32_t ar_osal_servreg_get_domainlist(ar_osal_servreg_entry_type *service, ar_osal_servreg_entry_type *domain_list, uint32_t *num_domains)
```

**Parameters**

<ParamField path="service" type="ar_osal_servreg_entry_type *">
  service(provider/service) for which domain(s) list is required.
</ParamField>

<ParamField path="domain_list" type="ar_osal_servreg_entry_type *">
  service supported in domain(s), client to provide . payload buffer pointer.
</ParamField>

<ParamField path="num_domains" type="uint32_t *">
  Client to provide the num\_domains to get the domain list. . If num\_domains is zero and domain\_list is NULL, API will return . the number of domains for the given service if available.
</ParamField>

**Returns**

0  Success Nonzero  Failure AR\_ENOMEMORY- Failed due to insufficient memory, client to call the API again with required size as returned in num\_domains.

### `ar_osal_servreg_register`

ar\_osal\_servreg\_register Service client(s) to register for the domain service state change notifications.

```cpp theme={null}
ar_osal_servreg_t ar_osal_servreg_register(ar_osal_client_type client_type, ar_osal_servreg_callback cb_func, void *cb_context, ar_osal_servreg_entry_type *domain, ar_osal_servreg_entry_type *service)
```

**Parameters**

<ParamField path="client_type" type="ar_osal_client_type">
  indicates registering client is a listener or service provider.
</ParamField>

<ParamField path="[in" type="">
  opt] cb\_func: callback function pointer to get notifications on. . This is parameter is optional to Service provider registration.
</ParamField>

<ParamField path="[in" type="">
  opt] cb\_context: callback function payload/context provided by client. . This is parameter is optional to Service provider registration.
</ParamField>

<ParamField path="domain" type="ar_osal_servreg_entry_type *">
  domain of the service(msm/domain/subdomain) for which the . state change notifications to be provided.
</ParamField>

<ParamField path="service" type="ar_osal_servreg_entry_type *">
  service(provider/service) for which the . state change notifications to be provided.
</ParamField>

**Returns**

servreg\_handle on success. null on failure.

### `ar_osal_servreg_deregister`

ar\_osal\_servreg\_deregister Service client(s) to deregister for the service state change notifications.

```cpp theme={null}
int32_t ar_osal_servreg_deregister(ar_osal_servreg_t servreg_handle)
```

**Parameters**

<ParamField path="servreg_handle" type="ar_osal_servreg_t">
  interface handle returned by ar\_osal\_servreg\_register().
</ParamField>

**Returns**

0  Success Nonzero  Failure

### `ar_osal_servreg_set_state`

ar\_osal\_servreg\_set\_state Service provider to call this API to register its service states(UP/DOWN).

This API to be used only by the service provider(msm/domain/subdomain/provider/service) and not by service client(s).

```cpp theme={null}
int32_t ar_osal_servreg_set_state(ar_osal_servreg_t servreg_handle, ar_osal_service_state_type state)
```

**Parameters**

<ParamField path="servreg_handle" type="ar_osal_servreg_t">
  interface handle returned by ar\_osal\_servreg\_register().
</ParamField>

<ParamField path="state" type="ar_osal_service_state_type">
  new service state for service registered using ar\_osal\_servreg\_register().
</ParamField>

**Returns**

0  Success Nonzero  Failure

### `ar_osal_servreg_restart_service`

ar\_osal\_servreg\_restart\_service HLOS calls this API to trigger a restart (PDR or SSR) on a given processor

```cpp theme={null}
int32_t ar_osal_servreg_restart_service(ar_osal_servreg_t servreg_handle)
```

**Parameters**

<ParamField path="servreg_handle" type="ar_osal_servreg_t">
  interface handle returned by ar\_osal\_servreg\_register() which identifies the desired processor
</ParamField>

**Returns**

0  Success Nonzero  Failure

### `ar_osal_panic`

induce panic to crash the system

```cpp theme={null}
void ar_osal_panic()
```

## Type Definitions

### `ar_osal_servreg_t`

ar osal servreg type object.

```cpp theme={null}
typedef void * ar_osal_servreg_t
```

### `ar_osal_service_state_type`

Service state up/down indicator.

```cpp theme={null}
typedef enum ar_osal_service_state ar_osal_service_state_type
```

### `ar_osal_client_type`

Servreg client type: listener or service provider.

```cpp theme={null}
typedef enum ar_osal_client ar_osal_client_type
```

### `ar_osal_servreg_cb_event_type`

Servreg callback notify events.

```cpp theme={null}
typedef enum ar_osal_servreg_cb_event ar_osal_servreg_cb_event_type
```

### `ar_osal_servreg_state_notify_payload_type`

servreg service state notify callback payload.

```cpp theme={null}
typedef struct ar_osal_servreg_state_notify_payload ar_osal_servreg_state_notify_payload_type
```

### `ar_osal_servreg_callback`

ar\_osal\_servreg\_callback Callback function to notify clients for any changes in service state(up/down).

```cpp theme={null}
typedef void(* ar_osal_servreg_callback
```

## Enumerations

### `ar_osal_service_state`

Service state up/down indicator.

#### Values

| Name                         | Value | Description |
| ---------------------------- | ----- | ----------- |
| `AR_OSAL_SERVICE_STATE_DOWN` | = 0   |             |
| `AR_OSAL_SERVICE_STATE_UP`   | = 1   |             |

### `ar_osal_client`

Servreg client type: listener or service provider.

#### Values

| Name                              | Value | Description |
| --------------------------------- | ----- | ----------- |
| `AR_OSAL_CLIENT_INVALID`          | = 0   |             |
| `AR_OSAL_CLIENT_LISTENER`         | = 1   |             |
| `AR_OSAL_CLIENT_SERVICE_PROVIDER` | = 2   |             |

### `ar_osal_servreg_cb_event`

Servreg callback notify events.

#### Values

| Name                           | Value | Description |
| ------------------------------ | ----- | ----------- |
| `AR_OSAL_SERVICE_STATE_NOTIFY` | = 1   |             |

## Macros

### `AR_OSAL_SERVREG_NAME_LENGTH_MAX`

Max length of the domain name i.e "soc/domain/subdomain" or service name i.e "provider/service" is 64 bytes e.g.

```c theme={null}
#define AR_OSAL_SERVREG_NAME_LENGTH_MAX (64)
```