grpc_core::ExecCtx Class Reference

Execution context. More...

#include <exec_ctx.h>

Data Structures
struct	CombinerData

Public Member Functions
	ExecCtx ()
	Default Constructor. More...
	ExecCtx (uintptr_t fl)
	Parameterised Constructor. More...
virtual	~ExecCtx ()
	Destructor. More...
	ExecCtx (const ExecCtx &)=delete
	Disallow copy and assignment operators. More...
ExecCtx &	operator= (const ExecCtx &)=delete
unsigned	starting_cpu () const
CombinerData *	combiner_data ()
	Only to be used by grpc-combiner code. More...
grpc_closure_list *	closure_list ()
	Return pointer to grpc_closure_list. More...
uintptr_t	flags ()
	Return flags. More...
bool	HasWork ()
	Checks if there is work to be done. More...
bool	Flush ()
	Flush any work that has been enqueued onto this grpc_exec_ctx. More...
bool	IsReadyToFinish ()
	Returns true if we'd like to leave this execution context as soon as possible: useful for deciding whether to do something more or not depending on outside context. More...
grpc_millis	Now ()
	Returns the stored current time relative to start if valid, otherwise refreshes the stored time, sets it valid and returns the new value. More...
void	InvalidateNow ()
	Invalidates the stored time value. More...
void	SetNowIomgrShutdown ()
	To be used only by shutdown code in iomgr. More...
void	TestOnlySetNow (grpc_millis new_val)
	To be used only for testing. More...

Static Public Member Functions
static void	TestOnlyGlobalInit (gpr_timespec new_val)
static void	GlobalInit (void)
	Global initialization for ExecCtx. More...
static void	GlobalShutdown (void)
	Global shutdown for ExecCtx. More...
static ExecCtx *	Get ()
	Gets pointer to current exec_ctx. More...
static void	Set (ExecCtx *exec_ctx)
static void	Run (const DebugLocation &location, grpc_closure *closure, grpc_error *error)
static void	RunList (const DebugLocation &location, grpc_closure_list *list)

Protected Member Functions
virtual bool	CheckReadyToFinish ()
	Check if ready to finish. More...

Static Protected Member Functions
static void	operator delete (void *)
	Disallow delete on ExecCtx. More...

Detailed Description

Execution context.

A bag of data that collects information along a callstack. It is created on the stack at core entry points (public API or iomgr), and stored internally as a thread-local variable.

Generally, to create an exec_ctx instance, add the following line at the top of the public API entry point or at the start of a thread's work function :

grpc_core::ExecCtx exec_ctx;

Access the created ExecCtx instance using : grpc_core::ExecCtx::Get()

Specific responsibilities (this may grow in the future):

• track a list of core work that needs to be delayed until the base of the call stack (this provides a convenient mechanism to run callbacks without worrying about locking issues)
• provide a decision maker (via IsReadyToFinish) that provides a signal as to whether a borrowed thread should continue to do work or should actively try to finish up and get this thread back to its owner

CONVENTIONS:

• Instance of this must ALWAYS be constructed on the stack, never heap allocated.
• Do not pass exec_ctx as a parameter to a function. Always access it using grpc_core::ExecCtx::Get().
• NOTE: In the future, the convention is likely to change to allow only one ExecCtx on a thread's stack at the same time. The TODO below discusses this plan in more detail.

TODO(yashykt): Only allow one "active" ExecCtx on a thread at the same time. Stage 1: If a new one is created on the stack, it should just pass-through to the underlying ExecCtx deeper in the thread's stack. Stage 2: Assert if a 2nd one is ever created on the stack since that implies a core re-entry outside of application callbacks.

Constructor & Destructor Documentation

ExecCtx() [1/3]

grpc_core::ExecCtx::ExecCtx ( )

inline

Default Constructor.

ExecCtx() [2/3]

grpc_core::ExecCtx::ExecCtx ( uintptr_t  fl )

inline

Parameterised Constructor.

~ExecCtx()

virtual grpc_core::ExecCtx::~ExecCtx ( )

inlinevirtual

Destructor.

ExecCtx() [3/3]

grpc_core::ExecCtx::ExecCtx ( const ExecCtx &  )

delete

Disallow copy and assignment operators.

Member Function Documentation

CheckReadyToFinish()

virtual bool grpc_core::ExecCtx::CheckReadyToFinish ( )

inlineprotectedvirtual

Check if ready to finish.

Reimplemented in ExecCtxPluck, and ExecCtxNext.

closure_list()

grpc_closure_list* grpc_core::ExecCtx::closure_list ( )

inline

Return pointer to grpc_closure_list.

combiner_data()

CombinerData* grpc_core::ExecCtx::combiner_data ( )

inline

Only to be used by grpc-combiner code.

flags()

uintptr_t grpc_core::ExecCtx::flags ( )

inline

Return flags.

Flush()

bool grpc_core::ExecCtx::Flush

(

)

Flush any work that has been enqueued onto this grpc_exec_ctx.

Caller must guarantee that no interfering locks are held. Returns true if work was performed, false otherwise.

Get()

static ExecCtx* grpc_core::ExecCtx::Get ( )

inlinestatic

Gets pointer to current exec_ctx.

GlobalInit()

void grpc_core::ExecCtx::GlobalInit ( void  )

static

Global initialization for ExecCtx.

Called by iomgr.

GlobalShutdown()

static void grpc_core::ExecCtx::GlobalShutdown ( void  )

inlinestatic

Global shutdown for ExecCtx.

Called by iomgr.

HasWork()

bool grpc_core::ExecCtx::HasWork ( )

inline

Checks if there is work to be done.

InvalidateNow()

void grpc_core::ExecCtx::InvalidateNow ( )

inline

Invalidates the stored time value.

A new time value will be set on calling Now().

IsReadyToFinish()

bool grpc_core::ExecCtx::IsReadyToFinish ( )

inline

Returns true if we'd like to leave this execution context as soon as possible: useful for deciding whether to do something more or not depending on outside context.

Now()

grpc_millis grpc_core::ExecCtx::Now

(

)

Returns the stored current time relative to start if valid, otherwise refreshes the stored time, sets it valid and returns the new value.

operator delete()

static void grpc_core::ExecCtx::operator delete ( void *  )

inlinestaticprotected

Disallow delete on ExecCtx.

operator=()

ExecCtx& grpc_core::ExecCtx::operator= ( const ExecCtx &  )

delete

Run()

void grpc_core::ExecCtx::Run ( const DebugLocation &  location, grpc_closure *  closure, grpc_error *  error  )

static

RunList()

void grpc_core::ExecCtx::RunList ( const DebugLocation &  location, grpc_closure_list *  list  )

static

Set()

static void grpc_core::ExecCtx::Set ( ExecCtx *  exec_ctx )

inlinestatic

SetNowIomgrShutdown()

void grpc_core::ExecCtx::SetNowIomgrShutdown ( )

inline

To be used only by shutdown code in iomgr.

starting_cpu()

unsigned grpc_core::ExecCtx::starting_cpu ( ) const

inline

TestOnlyGlobalInit()

void grpc_core::ExecCtx::TestOnlyGlobalInit ( gpr_timespec  new_val )

static

TestOnlySetNow()

void grpc_core::ExecCtx::TestOnlySetNow ( grpc_millis  new_val )

inline

To be used only for testing.

Sets the now value.

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The documentation for this class was generated from the following files:

• src/core/lib/iomgr/exec_ctx.h
• src/core/lib/iomgr/exec_ctx.cc