Defines a broad set of APIs that allow the client application to query build and runtime properties of the enclosing system.
Runtime capabilities are boolean properties of a platform that can't be determined at compile-time. They may vary from device to device, but they will not change over the course of a single execution. They often specify particular behavior of other APIs within the bounds of their operating range.
kSbSystemCapabilityReversedEnterAndBack
Whether this system has reversed Enter and Back keys.
kSbSystemCapabilityCanQueryGPUMemoryStats
Whether this system has the ability to report on GPU memory usage. If (and only if) a system has this capability will SbSystemGetTotalGPUMemory() and SbSystemGetUsedGPUMemory() be valid to call.
kSbSystemCapabilitySetsInputTimestamp
Whether this system sets the timestamp
field of SbInputData . If the system does not set this field, then it will automatically be set; however, the relative time between input events likely will not be preserved, so time-related calculations (e.g. velocity for move events) will be incorrect.
Enumeration of network connection types.
kSbSystemConnectionTypeWired
The system is on a wired connection.
kSbSystemConnectionTypeWireless
The system is on a wireless connection.
kSbSystemConnectionTypeUnknown
The system connection type is unknown.
Enumeration of device types.
kSbSystemDeviceTypeBlueRayDiskPlayer
Blue-ray Disc Player (BDP).
kSbSystemDeviceTypeGameConsole
A relatively high-powered TV device used primarily for playing games.
kSbSystemDeviceTypeOverTheTopBox
Over the top (OTT) devices stream content via the Internet over another type of network, e.g. cable or satellite.
kSbSystemDeviceTypeSetTopBox
Set top boxes (STBs) stream content primarily over cable or satellite. Some STBs can also stream OTT content via the Internet.
kSbSystemDeviceTypeTV
A Smart TV is a TV that can directly run applications that stream OTT content via the Internet.
kSbSystemDeviceTypeDesktopPC
Desktop PC.
kSbSystemDeviceTypeAndroidTV
An Android TV Device.
kSbSystemDeviceTypeUnknown
Unknown device.
Enumeration of special paths that the platform can define.
kSbSystemPathContentDirectory
Path to where the local content files that ship with the binary are available.
kSbSystemPathCacheDirectory
Path to the directory that can be used as a local file cache, if available.
kSbSystemPathDebugOutputDirectory
Path to the directory where debug output (e.g. logs, trace output, screenshots) can be written into.
kSbSystemPathFontDirectory
Path to a directory where system font files can be found. Should only be specified on platforms that provide fonts usable by Starboard applications.
kSbSystemPathFontConfigurationDirectory
Path to a directory where system font configuration metadata can be found. May be the same directory as kSbSystemPathFontDirectory
, but not necessarily. Should only be specified on platforms that provide fonts usable by Starboard applications.
kSbSystemPathTempDirectory
Path to a directory where temporary files can be written.
kSbSystemPathTestOutputDirectory
Path to a directory where test results can be written.
kSbSystemPathExecutableFile
Full path to the executable file.
kSbSystemPathStorageDirectory
Path to a directory for permanent file storage. Both read and write access is required. This is where an app may store its persistent settings. The location should be user agnostic if possible.
Possible responses for SbSystemPlatformErrorCallback
.
kSbSystemPlatformErrorResponsePositive
kSbSystemPlatformErrorResponseNegative
kSbSystemPlatformErrorResponseCancel
Enumeration of possible values for the type
parameter passed to the SbSystemRaisePlatformError
function.
kSbSystemPlatformErrorTypeConnectionError
Cobalt received a network connection error, or a network disconnection event. If the response
passed to SbSystemPlatformErrorCallback
is kSbSystemPlatformErrorResponsePositive
then the request should be retried, otherwise the app should be stopped.
System properties that can be queried for. Many of these are used in User-Agent string generation.
kSbSystemPropertyCertificationScope
The certification scope that identifies a group of devices.
kSbSystemPropertyBase64EncodedCertificationSecret
The HMAC-SHA256 base64 encoded symmetric key used to sign a subset of the query parameters from the application startup URL.
kSbSystemPropertyChipsetModelNumber
The full model number of the main platform chipset, including any vendor- specific prefixes.
kSbSystemPropertyFirmwareVersion
The production firmware version number which the device is currently running.
kSbSystemPropertyFriendlyName
A friendly name for this actual device. It may include user-personalization like “Upstairs Bedroom.” It may be displayed to users as part of some kind of device selection (e.g. in-app DIAL).
kSbSystemPropertyManufacturerName
A deprecated alias for kSbSystemPropertyBrandName
.
kSbSystemPropertyBrandName
The name of the brand under which the device is being sold.
kSbSystemPropertyModelName
The final production model number of the device.
kSbSystemPropertyModelYear
The year the device was launched, e.g. “2016”.
kSbSystemPropertySystemIntegratorName
The corporate entity responsible for submitting the device to YouTube certification and for the device maintenance/updates.
kSbSystemPropertyPlatformName
The name of the operating system and platform, suitable for inclusion in a User-Agent, say.
kSbSystemPropertySpeechApiKey
The Google Speech API key. The platform manufacturer is responsible for registering a Google Speech API key for their products. In the API Console ( http://developers.google.com/console ), you can enable the Speech APIs and generate a Speech API key.
kSbSystemPropertyUserAgentAuxField
A field that, if available, is appended to the user agent
Pointer to a function to compare two items. The return value uses standard *cmp
semantics:
< 0
if a
is less than b
0
if the two items are equal
> 1
if a
is greater than b
a
: The first value to compare. b
: The second value to compare.
typedef int(* SbSystemComparator) (const void *a, const void *b)
A type that can represent a system error code across all Starboard platforms.
typedef int SbSystemError
Type of callback function that may be called in response to an error notification from SbSystemRaisePlatformError
. response
is a code to indicate the user's response, e.g. if the platform raised a dialog to notify the user of the error. user_data
is the opaque pointer that was passed to the call to SbSystemRaisePlatformError
.
typedef void(* SbSystemPlatformErrorCallback) (SbSystemPlatformErrorResponse response, void *user_data)
Binary searches a sorted table base
of element_count
objects, each element element_width
bytes in size for an element that comparator
compares equal to key
.
This function is meant to be a drop-in replacement for bsearch
.
key
: The key to search for in the table. base
: The sorted table of elements to be searched. element_count
: The number of elements in the table. element_width
: The size, in bytes, of each element in the table. comparator
: A value that indicates how the element in the table should compare to the specified key
.
void* SbSystemBinarySearch(const void *key, const void *base, size_t element_count, size_t element_width, SbSystemComparator comparator)
Breaks the current program into the debugger, if a debugger is attached. If a debugger is not attached, this function aborts the program.
SB_NORETURN void SbSystemBreakIntoDebugger()
Clears the last error set by a Starboard call in the current thread.
void SbSystemClearLastError()
Returns the device's current network connection type.
SbSystemConnectionType SbSystemGetConnectionType()
Returns the type of the device.
SbSystemDeviceType SbSystemGetDeviceType()
Generates a human-readable string for an error. The return value specifies the total desired length of the string.
error
: The error for which a human-readable string is generated. out_string
: The generated string. This value may be null, and it is always terminated with a null byte. string_length
: The maximum length of the error string.
int SbSystemGetErrorString(SbSystemError error, char *out_string, int string_length)
Gets the last platform-specific error code produced by any Starboard call in the current thread for diagnostic purposes. Semantic reactions to Starboard function call results should be modeled explicitly.
SbSystemError SbSystemGetLastError()
Gets the system's current POSIX-style Locale ID. The locale represents the location, language, and cultural conventions that the system wants to use, which affects which text is displayed to the user as well as how displayed numbers, dates, currency, and similar values are formatted.
At its simplest, the locale ID can just be a BCP 47 language code, like en_US
. Currently, POSIX also wants to include the encoding as in en_US.UTF8
. POSIX also allows a couple very bare-bones locales, like “C” or “POSIX”, but they are not supported here. POSIX also supports different locale settings for a few different purposes, but Starboard only exposes one locale at a time.
RFC 5646 describes BCP 47 language codes: https://tools.ietf.org/html/bcp47
For more information than you probably want about POSIX locales, see: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap07.html
const char* SbSystemGetLocaleId()
Returns the number of processor cores available to this application. If the process is sandboxed to a subset of the physical cores, the function returns that sandboxed limit.
int SbSystemGetNumberOfProcessors()
Retrieves the platform-defined system property specified by property_id
and places its value as a zero-terminated string into the user-allocated out_value
unless it is longer than value_length
- 1. This implementation must be thread- safe.
This function returns true
if the property is retrieved successfully. It returns false
under any of the following conditions and, in any such case, out_value
is not changed:
property_id
is invalid for this platform
value_length
is too short for the given result
out_value
is NULL
property_id
: The system path to be retrieved. out_value
: The platform- defined system property specified by property_id
. value_length
: The length of the system property.
bool SbSystemGetProperty(SbSystemPropertyId property_id, char *out_value, int value_length)
A cryptographically secure random number generator that produces an arbitrary, non-negative number of buffer_size
random, non-negative bytes. The generated number is placed in out_buffer
. This function does not require manual seeding.
out_buffer
: A pointer for the generated random number. This value must not be null. buffer_size
: The size of the random number, in bytes.
void SbSystemGetRandomData(void *out_buffer, int buffer_size)
A cryptographically secure random number generator that gets 64 random bits and returns them as an uint64_t
. This function does not require manual seeding.
uint64_t SbSystemGetRandomUInt64()
Places up to stack_size
instruction pointer addresses of the current execution stack into out_stack
. The return value specifies the number of entries added.
The returned stack frames are in “downward” order from the calling frame toward the entry point of the thread. So, if all the stack frames do not fit, the ones truncated will be the less interesting ones toward the thread entry point.
This function is used in crash signal handlers and, therefore, it must be async- signal-safe on platforms that support signals. The following document discusses what it means to be async-signal-safe on POSIX: http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html#tag_02_04_03
out_stack
: A non-NULL array of void *
of at least stack_size
entries. stack_size
: The maximum number of instruction pointer addresses to be placed into out_stack
from the current execution stack.
int SbSystemGetStack(void **out_stack, int stack_size)
Returns the total CPU memory (in bytes) potentially available to this application. If the process is sandboxed to a maximum allowable limit, the function returns the lesser of the physical and sandbox limits.
int64_t SbSystemGetTotalCPUMemory()
Returns the total GPU memory (in bytes) available for use by this application. This function may only be called the return value for calls to SbSystemHasCapability(kSbSystemCapabilityCanQueryGPUMemoryStats) is true
.
int64_t SbSystemGetTotalGPUMemory()
Returns the total physical CPU memory (in bytes) used by this application. This value should always be less than (or, in particularly exciting situations, equal to) SbSystemGetTotalCPUMemory().
int64_t SbSystemGetUsedCPUMemory()
Returns the current amount of GPU memory (in bytes) that is currently being used by this application. This function may only be called if the return value for calls to SbSystemHasCapability(kSbSystemCapabilityCanQueryGPUMemoryStats) is true
.
int64_t SbSystemGetUsedGPUMemory()
Returns whether the platform has the runtime capability specified by capability_id
. Returns false for any unknown capabilities. This implementation must be thread-safe.
capability_id
: The runtime capability to check.
bool SbSystemHasCapability(SbSystemCapabilityId capability_id)
Hides the system splash screen on systems that support a splash screen that is displayed while the application is loading. This function may be called from any thread and must be idempotent.
void SbSystemHideSplashScreen()
Attempts to determine whether the current program is running inside or attached to a debugger. The function returns false
if neither of those cases is true.
bool SbSystemIsDebuggerAttached()
Cobalt calls this function to notify the platform that an error has occurred in the application that the platform may need to handle. The platform is expected to then notify the user of the error and to provide a means for any required interaction, such as by showing a dialog.
The return value is a boolean. If the platform cannot respond to the error, then this function should return false
, otherwise it should return true
.
This function may be called from any thread, and it is the platform's responsibility to decide how to handle an error received while a previous error is still pending. If that platform can only handle one error at a time, then it may queue the second error or ignore it by returning kSbSystemPlatformErrorInvalid
.
type
: An error type, from the SbSystemPlatformErrorType enum, that defines the error. callback
: A function that may be called by the platform to let the caller know that the user has reacted to the error. user_data
: An opaque pointer that the platform should pass as an argument to the callback function, if it is called.
bool SbSystemRaisePlatformError(SbSystemPlatformErrorType type, SbSystemPlatformErrorCallback callback, void *user_data)
Requests that the application move into the Paused state at the next convenient point. This should roughly correspond to “unfocused application” in a traditional window manager, where the application may be partially visible.
This function eventually causes a kSbEventTypePause
event to be dispatched to the application. Before the kSbEventTypePause
event is dispatched, some work may continue to be done, and unrelated system events may be dispatched.
void SbSystemRequestPause()
Requests that the application be terminated gracefully at the next convenient point. In the meantime, some work may continue to be done, and unrelated system events may be dispatched. This function eventually causes a kSbEventTypeStop
event to be dispatched to the application. When the process finally terminates, it returns error_level
, if that has any meaning on the current platform.
error_level
: An integer that serves as the return value for the process that is eventually terminated as a result of a call to this function.
void SbSystemRequestStop(int error_level)
Requests that the application move into the Suspended state at the next convenient point. This should roughly correspond to “minimization” in a traditional window manager, where the application is no longer visible.
This function eventually causes a kSbEventTypeSuspend
event to be dispatched to the application. Before the kSbEventTypeSuspend
event is dispatched, some work may continue to be done, and unrelated system events may be dispatched.
In the Suspended state, the application will be resident, but probably not running. The expectation is that an external system event will bring the application out of the Suspended state.
void SbSystemRequestSuspend()
Requests that the application move into the Started state at the next convenient point. This should roughly correspond to a “focused application” in a traditional window manager, where the application is fully visible and the primary receiver of input events.
This function eventually causes a kSbEventTypeUnpause
event to be dispatched to the application. Before kSbEventTypeUnpause
is dispatched, some work may continue to be done, and unrelated system events may be dispatched.
void SbSystemRequestUnpause()
Computes a HMAC-SHA256 digest of message
into digest
using the application's certification secret.
This function may be implemented as an alternative to implementing SbSystemGetProperty(kSbSystemPropertyBase64EncodedCertificationSecret), however both should not be implemented.
The output will be written into digest
. digest_size_in_bytes
must be 32 (or greater), since 32-bytes will be written into it. Returns false in the case of an error, or if it is not implemented. In this case the contents of digest
will be undefined.
bool SbSystemSignWithCertificationSecretKey(const uint8_t *message, size_t message_size_in_bytes, uint8_t *digest, size_t digest_size_in_bytes)
Sorts an array of elements base
, with element_count
elements of element_width
bytes each, using comparator
as the comparison function.
This function is meant to be a drop-in replacement for qsort
.
base
: The array of elements to be sorted. element_count
: The number of elements in the array. element_width
: The size, in bytes, of each element in the array. comparator
: A value that indicates how the array should be sorted.
void SbSystemSort(void *base, size_t element_count, size_t element_width, SbSystemComparator comparator)
Returns false if the platform doesn't need resume after suspend support. In such case Cobalt will free up the resource it retains for resume after suspend. Note that if this function returns false, the Starboard implementation cannot send kSbEventTypeResume to the event handler. The return value of this function cannot change over the life time of the application.
bool SbSystemSupportsResume()
Looks up address
as an instruction pointer and places up to (buffer_size - 1
) characters of the symbol associated with it in out_buffer
, which must not be NULL. out_buffer
will be NULL-terminated.
The return value indicates whether the function found a reasonable match for address
. If the return value is false
, then out_buffer
is not modified.
This function is used in crash signal handlers and, therefore, it must be async- signal-safe on platforms that support signals.
bool SbSystemSymbolize(const void *address, char *out_buffer, int buffer_size)