dispatch.h File Reference

The API to lib/barrelfish/dispatch. More...

Macros
#define	DISPATCHER_STACK_BYTES   (8192) /* 8kB */
	Stack size for dispatcher, in words.

Functions
void	disp_init_disabled (dispatcher_handle_t handle)
	Initialise the dispatcher, while disabled. More...
dispatcher_handle_t	disp_disable (void)
	Disable the dispatcher. More...
dispatcher_handle_t	disp_try_disable (bool *was_enabled)
	Try to disable the dispatcher. More...
void	disp_enable (dispatcher_handle_t handle)
	Re-enable the dispatcher. More...
void	disp_arch_init (dispatcher_handle_t handle)
	Architecture-specific dispatcher initialisation.
void	disp_resume (dispatcher_handle_t handle, arch_registers_state_t *archregs)
	Resume execution of a given register state. More...
void	disp_switch (dispatcher_handle_t handle, arch_registers_state_t *from_state, arch_registers_state_t *to_state)
	Switch execution between two register states, and turn off disabled activations. More...
void	disp_save (dispatcher_handle_t handle, arch_registers_state_t *state, bool yield, capaddr_t yield_to)
	Save the current register state and optionally yield the CPU. More...
void	disp_save_rm_kcb (void)
	Save register state, remove our KCB from current CPU.
void	disp_yield_disabled (dispatcher_handle_t handle)
	Yield the dispatcher's CPU. More...
const char *	disp_name (void)
	Return a pointer to the name field of the current dispatcher. More...

Detailed Description

The API to lib/barrelfish/dispatch.

Function Documentation

dispatcher_handle_t disp_disable

(

void

)

Disable the dispatcher.

This function disables the current dispatcher, returning a pointer to it. The dispatcher must be enabled.

While the dispatcher is disabled, the current thread cannot be preempted, and no incoming LMP messages can be received.

void disp_enable

(

dispatcher_handle_t

handle

)

Re-enable the dispatcher.

This function re-enables the current dispatcher. The dispatcher must be disabled.

void disp_init_disabled

(

dispatcher_handle_t

handle

)

Initialise the dispatcher, while disabled.

This function is called to setup the dispatcher structure while still disabled.

Parameters

disp	Dispatcher

const char* disp_name

(

void

)

Return a pointer to the name field of the current dispatcher.

May be called when the dispatcher is either enabled or disabled.

Returns

a string of at most #DISP_NAME_LEN characters, which may not be nul-terminated.

void disp_resume	(	dispatcher_handle_t	handle,
		arch_registers_state_t *	archregs
	)

Resume execution of a given register state.

This function resumes the execution of the given register state on the current dispatcher. It may only be called while the dispatcher is disabled.

Parameters

disp	Current dispatcher pointer
regs	Register state snapshot

void disp_save	(	dispatcher_handle_t	handle,
		arch_registers_state_t *	state,
		bool	yield,
		capaddr_t	yield_to
	)

Save the current register state and optionally yield the CPU.

This function saves as much as necessary of the current register state (which, when resumed will return to the caller), and then either re-enters the thread scheduler or yields the CPU. It may only be called while the dispatcher is disabled. Note that the thread context saved is a voluntary save so only callee save registers need to be saved, but we dont currently provide any way to optimise the corresponding resume.

Parameters

disp	Current dispatcher pointer
regs	Location to save current register state
yield	If true, yield CPU to kernel; otherwise re-run thread scheduler
yield_to	Endpoint capability for dispatcher to which we want to yield

This function saves as much as necessary of the current register state (which, when resumed will return to the caller), and then either re-enters the thread scheduler or yields the CPU. It may only be called while the dispatcher is disabled.

Parameters

disp	Current dispatcher pointer
regs	Location to save current register state
yield	If true, yield CPU to kernel; otherwise re-run thread scheduler
yield_to	Endpoint capability for dispatcher to which we want to yield

void disp_switch	(	dispatcher_handle_t	handle,
		arch_registers_state_t *	from_state,
		arch_registers_state_t *	to_state
	)

Switch execution between two register states, and turn off disabled activations.

This function saves as much as necessary of the current register state (which, when resumed will return to the caller), and switches execution by resuming the given register state. It may only be called while the dispatcher is disabled. A side effect is that activations are reenabled. Note that the thread context saved is a voluntary save so only callee save registers need to be saved, but we dont currently provide any way to optimise the corresponding resume.

Parameters

disp	Current dispatcher pointer
from_regs	Location to save current register state
to_regs	Location from which to resume new register state

Switch execution between two register states, and turn off disabled activations.

This function saves as much as necessary of the current register state (which, when resumed will return to the caller), and switches execution by resuming the given register state. It may only be called while the dispatcher is disabled.

Parameters

disp	Current dispatcher pointer
from_regs	Location to save current register state
to_regs	Location from which to resume new register state

dispatcher_handle_t disp_try_disable

(

bool *

was_enabled

)

Try to disable the dispatcher.

This function disables the current dispatcher if it's enabled and returns a pointer to it.

While the dispatcher is disabled, the current thread cannot be preempted, and no incoming LMP messages can be received.

Parameters

was_enabled

True, if the dispatcher was enabled

void disp_yield_disabled

(

dispatcher_handle_t

handle

)

Yield the dispatcher's CPU.

This function yields the CPU. It may only be called while disabled.

Parameters

disp	Current dispatcher