module xdc.runtime.knl.GateProcess

Provides protection of critical sections across processes

This module provides services through its proxy IGateProcessSupport interface. It has a module wide config parameter Proxy which needs to be bound to an OS specific delegate before this module can be used. [ more ... ]
C synopsis target-domain sourced in xdc/runtime/knl/GateProcess.xdc
#include <xdc/runtime/knl/GateProcess.h>
Functions
Void
Void
Void
Int 
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
#define
Typedefs
typedef struct
typedef struct
typedef struct
Constants
extern const Assert_Id 
 
DETAILS
This module provides services through its proxy IGateProcessSupport interface. It has a module wide config parameter Proxy which needs to be bound to an OS specific delegate before this module can be used.
Here is an example showing how the proxy is bound to an BIOS 6.x specific delegate.
  var GateProcess = xdc.useModule('xdc.runtime.knl.GateProcess');
  GateProcess.Proxy = 
      xdc.useModule('ti.sysbios.xdcruntime.GateProcessSupport');
Typically the package containing the delegates have a Settings module that will bind all xdc.runtime.knl proxies. The following example sets up all the xdc.runtime.knl proxies.
  xdc.useModule("ti.sysbios.xdcruntime.Settings");
 
const GateProcess_GETREFCOUNT_FAILED

Status returned by getReferenceCount when there is an error

C synopsis target-domain
#define GateProcess_GETREFCOUNT_FAILED (Int)-1
 
 
const GateProcess_Q_BLOCKING

Blocking quality

C synopsis target-domain
#define GateProcess_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 GateProcess_Q_PREEMPTING

Preempting quality

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

Assert when an invalid key is passed to create

C synopsis target-domain
extern const Assert_Id GateProcess_A_invalidKey;
 
 
GateProcess_query()  // module-wide

Runtime test for a particular gate quality

C synopsis target-domain
Bool GateProcess_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 GateProcess_Module_id();
// Get this module's unique id
 
Bool GateProcess_Module_startupDone();
// Test if this module has completed startup
 
IHeap_Handle GateProcess_Module_heap();
// The heap from which this module allocates memory
 
Bool GateProcess_Module_hasMask();
// Test whether this module has a diagnostics mask
 
Bits16 GateProcess_Module_getMask();
// Returns the diagnostics mask for this module
 
Void GateProcess_Module_setMask(Bits16 mask);
// Set the diagnostics mask for this module
Instance Object Types

C synopsis target-domain
typedef struct GateProcess_Object GateProcess_Object;
// Opaque internal representation of an instance object
 
typedef GateProcess_Object *GateProcess_Handle;
// Client reference to an instance object
 
typedef struct GateProcess_Struct GateProcess_Struct;
// Opaque client structure large enough to hold an instance object
 
GateProcess_Handle GateProcess_handle(GateProcess_Struct *structP);
// Convert this instance structure pointer into an instance handle
 
GateProcess_Struct *GateProcess_struct(GateProcess_Handle handle);
// Convert this instance handle into an instance structure pointer
Instance Config Parameters

C synopsis target-domain
typedef struct GateProcess_Params {
// Instance config-params structure
    IInstance_Params *instance;
    // Common per-instance configs
    Int key;
    // globally unique key for SysV-style semaphore
} GateProcess_Params;
 
Void GateProcess_Params_init(GateProcess_Params *params);
// Initialize this config-params structure with supplier-specified defaults before instance creation
 
config GateProcess_key  // instance

globally unique key for SysV-style semaphore

C synopsis target-domain
      ...
    Int key;
 
DETAILS
This is a required parameter.
Instance Creation

C synopsis target-domain
GateProcess_Handle GateProcess_create(const GateProcess_Params *params, Error_Block *eb);
// Allocate and initialize a new instance object and return its handle
 
Void GateProcess_construct(GateProcess_Struct *structP, const GateProcess_Params *params, Error_Block *eb);
// 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)
DETAILS
This function creates a new GateProcess object which is initialized to count. All gates created with the same key reference the same underlying synchronization object and work between processes. For compatibility with the IGateProvider interface the argument key is passes in the params struct rather than as a full argument, but it is required. Therefore calling this function with a NULL params struct is illegal.
Instance Deletion

C synopsis target-domain
Void GateProcess_delete(GateProcess_Handle *handleP);
// Finalize and free this previously allocated instance object, setting the referenced handle to NULL
 
Void GateProcess_destruct(GateProcess_Struct *structP);
// Finalize the instance object inside the provided structure
 
GateProcess_enter()  // instance

Enter this gate

C synopsis target-domain
IArg GateProcess_enter(GateProcess_Handle handle);
 
ARGUMENTS
handle — handle of a previously-created GateProcess 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.
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.
 
GateProcess_getReferenceCount()  // instance

Get the number of processes with references to this Gate

C synopsis target-domain
Int GateProcess_getReferenceCount(GateProcess_Handle handle, Error_Block *eb);
 
ARGUMENTS
handle — handle of a previously-created GateProcess instance object
eb — Pointer to Error.Block
RETURNS
Returns the number of processes that possess a reference to this gate, or GETREFCOUNT_FAILED if an error occured.
 
GateProcess_leave()  // instance

Leave this gate

C synopsis target-domain
Void GateProcess_leave(GateProcess_Handle handle, IArg key);
 
ARGUMENTS
handle — handle of a previously-created GateProcess 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).
Instance Convertors

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

C synopsis target-domain
Int GateProcess_Object_count();
// The number of statically-created instance objects
 
GateProcess_Handle GateProcess_Object_get(GateProcess_Object *array, Int i);
// The handle of the i-th statically-created instance object (array == NULL)
 
GateProcess_Handle GateProcess_Object_first();
// The handle of the first dynamically-created instance object, or NULL
 
GateProcess_Handle GateProcess_Object_next(GateProcess_Handle handle);
// The handle of the next dynamically-created instance object, or NULL
 
IHeap_Handle GateProcess_Object_heap();
// The heap used to allocate dynamically-created instance objects
 
Types_Label *GateProcess_Handle_label(GateProcess_Handle handle, Types_Label *buf);
// The label associated with this instance object
 
String GateProcess_Handle_name(GateProcess_Handle handle);
// The name of this instance object
 
XDCscript usage meta-domain sourced in xdc/runtime/knl/GateProcess.xdc
var GateProcess = xdc.useModule('xdc.runtime.knl.GateProcess');
local proxy modules
        GateProcess.Proxy.delegate$ = IGateProcessSupport.Module null
        GateProcess.Proxy.abstractInstances$ = false
module-wide constants & types
module-wide config parameters
        msg: "A_invalidKey: the key must be set to a non-default value"
    };
 
module-wide functions
per-instance config parameters
    var params = new GateProcess.Params// Instance config-params object;
        params.key// globally unique key for SysV-style semaphore = Int -1;
per-instance creation
    var inst = GateProcess.create// Create an instance-object(params);
 
 
proxy GateProcess.Proxy

Proxy that needs to be bound to an OS specific delegate

XDCscript usage meta-domain
GateProcess.Proxy = IGateProcessSupport.Module null
// some delegate module inheriting the IGateProcessSupport interface
    GateProcess.Proxy.delegate$ = IGateProcessSupport.Module null
    // explicit access to the currently bound delegate module
    GateProcess.Proxy.abstractInstances$ = false
    // use indirect runtime function calls if true
 
 
const GateProcess.GETREFCOUNT_FAILED

Status returned by getReferenceCount when there is an error

XDCscript usage meta-domain
const GateProcess.GETREFCOUNT_FAILED = -1;
 
C SYNOPSIS
 
const GateProcess.Q_BLOCKING

Blocking quality

XDCscript usage meta-domain
const GateProcess.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 GateProcess.Q_PREEMPTING

Preempting quality

XDCscript usage meta-domain
const GateProcess.Q_PREEMPTING = 2;
 
DETAILS
Gates with this "quality" allow other threads to preempt the thread that has already entered the gate.
C SYNOPSIS
 
config GateProcess.A_invalidKey  // module-wide

Assert when an invalid key is passed to create

XDCscript usage meta-domain
GateProcess.A_invalidKey = Assert.Desc {
    msg: "A_invalidKey: the key must be set to a non-default value"
};
 
C SYNOPSIS
 
metaonly config GateProcess.common$  // module-wide

Common module configuration parameters

XDCscript usage meta-domain
GateProcess.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 GateProcess.queryMeta()  // module-wide

Configuration time test for a particular gate quality

XDCscript usage meta-domain
GateProcess.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

XDCscript usage meta-domain
var params = new GateProcess.Params;
// Instance config-params object
    params.key = Int -1;
    // globally unique key for SysV-style semaphore
 
config GateProcess.key  // instance

globally unique key for SysV-style semaphore

XDCscript usage meta-domain
var params = new GateProcess.Params;
  ...
params.key = Int -1;
 
DETAILS
This is a required parameter.
C SYNOPSIS
Instance Creation

XDCscript usage meta-domain
var params = new GateProcess.Params;
// Allocate instance config-params
params.config =   ...
// Assign individual configs
 
var inst = GateProcess.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)
DETAILS
This function creates a new GateProcess object which is initialized to count. All gates created with the same key reference the same underlying synchronization object and work between processes. For compatibility with the IGateProvider interface the argument key is passes in the params struct rather than as a full argument, but it is required. Therefore calling this function with a NULL params struct is illegal.
generated on Thu, 01 Mar 2012 16:58:45 GMT