FutexMap class holds a map of all futexes used in the system. More...

#include <futex_map.hh>

Inheritance diagram for gem5::FutexMap:

Public Member Functions
void	suspend (Addr addr, uint64_t tgid, ThreadContext *tc)
	Inserts a futex into the map with one waiting TC.

int	wakeup (Addr addr, uint64_t tgid, int count)
	Wakes up at most count waiting threads on a futex.

void	suspend_bitset (Addr addr, uint64_t tgid, ThreadContext *tc, int bitmask)

int	wakeup_bitset (Addr addr, uint64_t tgid, int bitmask)

int	requeue (Addr addr1, uint64_t tgid, int count, int count2, Addr addr2)
	This operation wakes a given number (val) of waiters.

bool	is_waiting (ThreadContext *tc)
	Determine if the given thread context is currently waiting on a futex wait operation on any of the futexes tracked by this FutexMap.

Private Attributes
std::unordered_set< ThreadContext * >	waitingTcs

Detailed Description

FutexMap class holds a map of all futexes used in the system.

Definition at line 109 of file futex_map.hh.

Member Function Documentation

◆ is_waiting()

bool gem5::FutexMap::is_waiting ( ThreadContext * tc )

Determine if the given thread context is currently waiting on a futex wait operation on any of the futexes tracked by this FutexMap.

Definition at line 185 of file futex_map.cc.

References waitingTcs.

Referenced by gem5::BaseCPU::postInterrupt().

◆ requeue()

int gem5::FutexMap::requeue	(	Addr	addr1,
		uint64_t	tgid,
		int	count,
		int	count2,
		Addr	addr2 )

This operation wakes a given number (val) of waiters.

If there are more threads waiting than woken, they are removed from the wait queue of the futex pointed to by addr1 and added to the wait queue of the futex pointed to by addr2. The number of waiter moved is capped by count2 (misused timeout parameter).

The return value is the number of waiters that are woken or requeued.

Definition at line 141 of file futex_map.cc.

References gem5::X86ISA::count, gem5::ArmISA::it1, gem5::ArmISA::it2, and gem5::MipsISA::w.

Referenced by gem5::futexFunc().