simple_spinlock_t Struct Reference

Structure representing a simple spinlock. More...

#include <k_spinlock.h>

Public Attributes
volatile int	locked
	The lock state. 0 for unlocked, 1 for locked.
unsigned long	acquisitions
	Number of times the lock was successfully acquired.
unsigned long	contentions
	Number of times a thread tried to acquire the lock but found it already held, thus entering a spin-wait loop. This indicates contention.

Detailed Description

Structure representing a simple spinlock.

The spinlock's state is determined by the locked member. It also includes basic statistics for acquisitions and contentions. It is crucial that operations on this structure use the provided simple_spin_* functions to ensure atomicity and correct memory ordering.

Member Data Documentation

acquisitions

unsigned long simple_spinlock_t::acquisitions

Number of times the lock was successfully acquired.

contentions

unsigned long simple_spinlock_t::contentions

Number of times a thread tried to acquire the lock but found it already held, thus entering a spin-wait loop. This indicates contention.

locked

volatile int simple_spinlock_t::locked

The lock state. 0 for unlocked, 1 for locked.

volatile ensures that the compiler does not optimize away reads of this variable, as its value can change unexpectedly due to actions from other CPUs or threads. The atomicity of lock operations is guaranteed by GCC's __sync_* builtins, not by volatile itself.

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

• minix/kernel/k_spinlock.h