hermes.backplane.sync.FrameBarrier Class Reference

Public Member Functions
None	__init__ (self, str name, int count)
str	name (self)
int	count (self)
None	create (self)
None	attach (self)
None	signal_step (self)
bool	wait_step (self, float|None timeout=None)
None	signal_done (self)
bool	wait_all_done (self, float|None timeout=None)
None	close (self)
None	destroy (self)
FrameBarrier	__enter__ (self)
None	__exit__ (self, *object args)

Protected Attributes
str	_name = name
int	_count = count
posix_ipc.Semaphore|None	_step_sem = None
posix_ipc.Semaphore|None	_done_sem = None

Detailed Description

Synchronization barrier for frame execution.

Coordinates multiple module processes to execute frames in lockstep.
Uses two semaphores:
- step_sem: Scheduler signals modules to start stepping
- done_sem: Modules signal completion to scheduler

Example:
    # Scheduler side
    barrier = FrameBarrier("/hermes_barrier", count=3)
    barrier.create()
    barrier.signal_step()  # Release all modules
    barrier.wait_all_done()  # Wait for all to finish

    # Module side
    barrier = FrameBarrier("/hermes_barrier", count=3)
    barrier.attach()
    barrier.wait_step()  # Wait for scheduler
    # ... execute frame ...
    barrier.signal_done()  # Signal completion

Constructor & Destructor Documentation

__init__()

None hermes.backplane.sync.FrameBarrier.__init__	(		self,
		str	name,
		int	count )

Initialize frame barrier.

Args:
    name: Base name for semaphores (e.g., "/hermes_barrier")
    count: Number of module processes to synchronize

Raises:
    SemaphoreError: If count is less than 1

Member Function Documentation

__enter__()

FrameBarrier hermes.backplane.sync.FrameBarrier.__enter__

(

self

)

__exit__()

None hermes.backplane.sync.FrameBarrier.__exit__	(		self,
		*object	args )

attach()

None hermes.backplane.sync.FrameBarrier.attach

(

self

)

Attach to existing barrier semaphores.

Raises:
    SemaphoreError: If already attached
    posix_ipc.ExistentialError: If semaphores don't exist

close()

None hermes.backplane.sync.FrameBarrier.close

(

self

)

Close semaphore handles without destroying.

count()

int hermes.backplane.sync.FrameBarrier.count

(

self

)

Number of processes to synchronize.

create()

None hermes.backplane.sync.FrameBarrier.create

(

self

)

Create barrier semaphores.

Raises:
    SemaphoreError: If already created
    posix_ipc.ExistentialError: If semaphores already exist

destroy()

None hermes.backplane.sync.FrameBarrier.destroy

(

self

)

Destroy the barrier semaphores.

Should only be called by the creator after all users close.

name()

str hermes.backplane.sync.FrameBarrier.name

(

self

)

Barrier name.

signal_done()

None hermes.backplane.sync.FrameBarrier.signal_done

(

self

)

Module: signal that step execution is complete.

signal_step()

None hermes.backplane.sync.FrameBarrier.signal_step

(

self

)

Scheduler: signal all modules to execute a step.

Releases the step semaphore `count` times so all modules
can proceed.

wait_all_done()

bool hermes.backplane.sync.FrameBarrier.wait_all_done	(		self,
		float | None	timeout = None )

Scheduler: wait for all modules to complete.

Args:
    timeout: Maximum seconds to wait per module, None for infinite

Returns:
    True if all done, False if any timeout

wait_step()

bool hermes.backplane.sync.FrameBarrier.wait_step	(		self,
		float | None	timeout = None )

Module: wait for step signal from scheduler.

Args:
    timeout: Maximum seconds to wait, None for infinite

Returns:
    True if signaled, False if timeout

Member Data Documentation

_count

hermes.backplane.sync.FrameBarrier._count = count

protected

_done_sem

posix_ipc.Semaphore | None hermes.backplane.sync.FrameBarrier._done_sem = None

protected

_name

str hermes.backplane.sync.FrameBarrier._name = name

protected

_step_sem

posix_ipc.Semaphore | None hermes.backplane.sync.FrameBarrier._step_sem = None

protected

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

• src/hermes/backplane/sync.py