module ti.sysbios.gates.GateSwi

Software Interrupt Gate

GateSwi uses disabling and enabling of software interrupts as the resource locking mechanism. This gate can be used whenever the resource is being shared by Swis or Tasks. This gate cannot be used by a Hwi. [ more ... ]
C synopsis target-domain sourced in ti/sysbios/gates/GateSwi.xdc
#include <ti/sysbios/gates/GateSwi.h>
Functions
Void
Void
Void
Void
Functions common to all IGateProvider modules
IArg 
Void 
Bool 
Functions common to all target instances
Functions common to all target modules
Defines
#define
#define
Typedefs
typedef GateSwi_Object *
typedef struct
typedef struct
typedef struct
Constants
extern const Assert_Id 
 
DETAILS
GateSwi uses disabling and enabling of software interrupts as the resource locking mechanism. This gate can be used whenever the resource is being shared by Swis or Tasks. This gate cannot be used by a Hwi.
The duration between the enter and leave should be as short as possible to minimize Swi latency.
GateSwi inherits from xdc.runtime.IGateProvider, therefore supports nesting.

Calling Context

Function Hwi Swi Task Main Startup
Params_init Y Y Y Y Y
query Y Y Y Y Y
construct Y Y Y Y N
create N* N* Y Y N
delete N* N* Y Y N
destruct Y Y Y Y N
enter N Y Y Y** N
leave N Y Y Y** N
Definitions:
  • Hwi: API is callable from a Hwi thread.
  • Swi: API is callable from a Swi thread.
  • Task: API is callable from a Task thread.
  • Main: API is callable during any of these phases:
    • In your module startup after this module is started (e.g. GateSwi_Module_startupDone() returns TRUE).
    • During xdc.runtime.Startup.lastFxns.
    • During main().
    • During BIOS.startupFxns.
  • Startup: API is callable during any of these phases:
    • During xdc.runtime.Startup.firstFxns.
    • In your module startup before this module is started (e.g. GateSwi_Module_startupDone() returns FALSE).
  • *: Assuming blocking Heap is used for creation.
  • **: Must be used in enter/leave pairs.
 
const GateSwi_Q_BLOCKING

Blocking quality

C synopsis target-domain
#define GateSwi_Q_BLOCKING (Int)1
 
DETAILS
Gates with this "quality" may cause the calling thread to block; i.e., suspend execution until another thread leaves the gate.
 
const GateSwi_Q_PREEMPTING

Preempting quality

C synopsis target-domain
#define GateSwi_Q_PREEMPTING (Int)2
 
DETAILS
Gates with this "quality" allow other threads to preempt the thread that has already entered the gate.
 
config GateSwi_A_badContext  // module-wide

Asserted when enter or leave is called from a hardware interrupt thread

C synopsis target-domain
extern const Assert_Id GateSwi_A_badContext;
 
 
GateSwi_query()  // module-wide

Runtime test for a particular gate quality

C synopsis target-domain
Bool GateSwi_query(Int qual);
 
ARGUMENTS
qual — constant describing a quality
RETURNS
Returns TRUE if the gate has the given quality, and FALSE otherwise, which includes the case when the gate does not recognize the constant describing the quality.
Module-Wide Built-Ins

C synopsis target-domain
Types_ModuleId GateSwi_Module_id();
// Get this module's unique id
 
Bool GateSwi_Module_startupDone();
// Test if this module has completed startup
 
IHeap_Handle GateSwi_Module_heap();
// The heap from which this module allocates memory
 
Bool GateSwi_Module_hasMask();
// Test whether this module has a diagnostics mask
 
Bits16 GateSwi_Module_getMask();
// Returns the diagnostics mask for this module
 
Void GateSwi_Module_setMask(Bits16 mask);
// Set the diagnostics mask for this module
Instance Object Types

C synopsis target-domain
typedef struct GateSwi_Object GateSwi_Object;
// Opaque internal representation of an instance object
 
typedef GateSwi_Object *GateSwi_Handle;
// Client reference to an instance object
 
typedef struct GateSwi_Struct GateSwi_Struct;
// Opaque client structure large enough to hold an instance object
 
GateSwi_Handle GateSwi_handle(GateSwi_Struct *structP);
// Convert this instance structure pointer into an instance handle
 
GateSwi_Struct *GateSwi_struct(GateSwi_Handle handle);
// Convert this instance handle into an instance structure pointer
Instance Config Parameters

C synopsis target-domain
typedef struct GateSwi_Params {
// Instance config-params structure
    IInstance_Params *instance;
    // Common per-instance configs
} GateSwi_Params;
 
Void GateSwi_Params_init(GateSwi_Params *params);
// Initialize this config-params structure with supplier-specified defaults before instance creation
Runtime Instance Creation

C synopsis target-domain
GateSwi_Handle GateSwi_create(const GateSwi_Params *params, Error_Block *eb);
// Allocate and initialize a new instance object and return its handle
 
Void GateSwi_construct(GateSwi_Struct *structP, const GateSwi_Params *params);
// Initialize a new instance object inside the provided structure
ARGUMENTS
params — per-instance config params, or NULL to select default values (target-domain only)
eb — active error-handling block, or NULL to select default policy (target-domain only)
Instance Deletion

C synopsis target-domain
Void GateSwi_delete(GateSwi_Handle *handleP);
// Finalize and free this previously allocated instance object, setting the referenced handle to NULL
 
Void GateSwi_destruct(GateSwi_Struct *structP);
// Finalize the instance object inside the provided structure
 
GateSwi_enter()  // instance

Disable Swi Scheduling

C synopsis target-domain
IArg GateSwi_enter(GateSwi_Handle handle);
 
ARGUMENTS
handle — handle of a previously-created GateSwi instance object
DETAILS
Each gate provider can implement mutual exclusion using different algorithms; e.g., disabling all scheduling, disabling the scheduling of all threads below a specified "priority level", suspending the caller when the gate has been entered by another thread and re-enabling it when the the other thread leaves the gate. However, in all cases, after this method returns that caller has exclusive access to the data protected by this gate.
A thread may reenter a gate without blocking or failing.
GateSwi_enter() disables all Swi functions from running until GateSwi_leave() is called. Hardware interrupts can still run.
Read the discussion of the side effects of disabling the Swi scheduler here.
RETURNS
Returns a "key" that is used to leave this gate; this value is used to restore thread preemption to the state that existed just prior to entering this gate.
 
GateSwi_leave()  // instance

Re-enable Swi Scheduling

C synopsis target-domain
Void GateSwi_leave(GateSwi_Handle handle, IArg key);
 
ARGUMENTS
handle — handle of a previously-created GateSwi instance object
key — the value returned by a matching call to enter
DETAILS
This method is only called by threads that have previously entered this gate via enter. After this method returns, the caller must not access the data structure protected by this gate (unless the caller has entered the gate more than once and other calls to leave remain to balance the number of previous calls to enter).
GateSwi_enter() disables all Swi functions from running until GateSwi_leave() is called. Hardware interrupts can still run.
Read the discussion of the side effects of disabling the Swi scheduler here.
Instance Convertors

C synopsis target-domain
IGateProvider_Handle GateSwi_Handle_upCast(GateSwi_Handle handle);
// unconditionally move one level up the inheritance hierarchy
 
GateSwi_Handle GateSwi_Handle_downCast(IGateProvider_Handle handle);
// conditionally move one level down the inheritance hierarchy; NULL upon failure
Instance Built-Ins

C synopsis target-domain
Int GateSwi_Object_count();
// The number of statically-created instance objects
 
GateSwi_Handle GateSwi_Object_get(GateSwi_Object *array, Int i);
// The handle of the i-th statically-created instance object (array == NULL)
 
GateSwi_Handle GateSwi_Object_first();
// The handle of the first dynamically-created instance object, or NULL
 
GateSwi_Handle GateSwi_Object_next(GateSwi_Handle handle);
// The handle of the next dynamically-created instance object, or NULL
 
IHeap_Handle GateSwi_Object_heap();
// The heap used to allocate dynamically-created instance objects
 
Types_Label *GateSwi_Handle_label(GateSwi_Handle handle, Types_Label *buf);
// The label associated with this instance object
 
String GateSwi_Handle_name(GateSwi_Handle handle);
// The name of this instance object
 
Configuration settings sourced in ti/sysbios/gates/GateSwi.xdc
var GateSwi = xdc.useModule('ti.sysbios.gates.GateSwi');
module-wide constants & types
module-wide config parameters
        msg: "A_badContext: bad calling context. May not be entered from a hardware interrupt thread."
    };
 
module-wide functions
per-instance config parameters
    var params = new GateSwi.Params// Instance config-params object;
per-instance creation
    var inst = GateSwi.create// Create an instance-object(params);
 
 
const GateSwi.Q_BLOCKING

Blocking quality

Configuration settings
const GateSwi.Q_BLOCKING = 1;
 
DETAILS
Gates with this "quality" may cause the calling thread to block; i.e., suspend execution until another thread leaves the gate.
C SYNOPSIS
 
const GateSwi.Q_PREEMPTING

Preempting quality

Configuration settings
const GateSwi.Q_PREEMPTING = 2;
 
DETAILS
Gates with this "quality" allow other threads to preempt the thread that has already entered the gate.
C SYNOPSIS
 
config GateSwi.A_badContext  // module-wide

Asserted when enter or leave is called from a hardware interrupt thread

Configuration settings
GateSwi.A_badContext = Assert.Desc {
    msg: "A_badContext: bad calling context. May not be entered from a hardware interrupt thread."
};
 
C SYNOPSIS
 
metaonly config GateSwi.common$  // module-wide

Common module configuration parameters

Configuration settings
GateSwi.common$ = Types.Common$ undefined;
 
DETAILS
All modules have this configuration parameter. Its name contains the '$' character to ensure it does not conflict with configuration parameters declared by the module. This allows new configuration parameters to be added in the future without any chance of breaking existing modules.
 
metaonly GateSwi.queryMeta()  // module-wide

Configuration time test for a particular gate quality

Configuration settings
GateSwi.queryMeta(Int qual) returns Bool
 
ARGUMENTS
qual — constant describing a quality
RETURNS
Returns TRUE if the gate has the given quality, and FALSE otherwise, which includes the case when the gate does not recognize the constant describing the quality.
Instance Config Parameters

Configuration settings
var params = new GateSwi.Params;
// Instance config-params object
Static Instance Creation

Configuration settings
var params = new GateSwi.Params;
// Allocate instance config-params
params.config =   ...
// Assign individual configs
 
var inst = GateSwi.create(params);
// Create an instance-object
ARGUMENTS
params — per-instance config params, or NULL to select default values (target-domain only)
eb — active error-handling block, or NULL to select default policy (target-domain only)
generated on Thu, 25 May 2017 22:10:07 GMT