#include <ShmConstructors.h>

Public Member Functions
	SegmentSemaphoreGuard (boost::interprocess::named_semaphore &semaphore, std::chrono::steady_clock::duration timeout=kDefaultWaitTimeout)

	~SegmentSemaphoreGuard ()

	SegmentSemaphoreGuard (const SegmentSemaphoreGuard &)=delete

SegmentSemaphoreGuard &	operator= (const SegmentSemaphoreGuard &)=delete

Static Public Attributes
static constexpr std::chrono::seconds	kDefaultWaitTimeout { 30 }

Detailed Description

RAII guard that acquires (default) the segment remap semaphore and releases it on destruction. Used as a cross-process mutex around the shared memory remap / construct critical sections.

The acquisition is bounded: a process that crashes while holding the semaphore leaves its count at zero forever, so an unbounded wait() would deadlock every other process. Instead the guard times out and throws, turning the silent hang into an actionable error (the orphaned handle can be inspected/removed out of band).

Constructor & Destructor Documentation

◆ SegmentSemaphoreGuard() [1/2]

lintel::shm::SegmentSemaphoreGuard::SegmentSemaphoreGuard	(	boost::interprocess::named_semaphore &	semaphore,
		std::chrono::steady_clock::duration	timeout = `kDefaultWaitTimeout`
	)

inlineexplicit

Parameters

semaphore	semaphore of the segment to guard
timeout	upper bound for acquiring the semaphore

Exceptions

std::runtime_error if the semaphore could not be acquired within the timeout (e.g. a previous holder crashed)

◆ ~SegmentSemaphoreGuard()

lintel::shm::SegmentSemaphoreGuard::~SegmentSemaphoreGuard ( )

inline

◆ SegmentSemaphoreGuard() [2/2]

lintel::shm::SegmentSemaphoreGuard::SegmentSemaphoreGuard ( const SegmentSemaphoreGuard & )

delete

Member Function Documentation

◆ operator=()

SegmentSemaphoreGuard & lintel::shm::SegmentSemaphoreGuard::operator= ( const SegmentSemaphoreGuard & )

delete

Member Data Documentation

◆ kDefaultWaitTimeout

constexpr std::chrono::seconds lintel::shm::SegmentSemaphoreGuard::kDefaultWaitTimeout { 30 }

staticconstexpr

Default time to wait for the semaphore before giving up. Generous, because the guarded critical sections are short (remap/construct).

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

src/include/lintel/features/base/services/ShmConstructors.h

Public Member Functions

Static Public Attributes