net_instaweb::MemLockState Class Reference

Captures and maintains scheduling order for locks with a common name. More...

#include "mem_lock_state.h"

Classes
struct	Comparator
struct	StealComparator

Public Types
typedef std::set< MemLock *, MemLockState::Comparator >	WakeupOrderedLockSet
typedef std::set< MemLock *, MemLockState::StealComparator >	StealOrderedLockSet

Public Member Functions
const GoogleString &	name () const
MemLock *	CreateLock (int64 sequence)
void	RemoveLock (MemLock *lock)
	Called when lock is deleted. More...
void	UnscheduleLock (MemLock *lock)
void	ScheduleLock (MemLock *lock)
bool	GrabLock (MemLock *lock)
void	Unlock ()
void	StealLock (MemLock *lock)
MemLockManager *	manager ()
bool	IsHeldInOrderedSet (MemLock *lock) const

Static Public Member Functions
template<typename T >
static int	Compare (const T &a, const T &b)

Friends
class	MemLockManager

Detailed Description

Captures and maintains scheduling order for locks with a common name.

Member Function Documentation

MemLock* net_instaweb::MemLockState::CreateLock

(

int64

sequence

)

Creates a new lock for this name, and track it. Note that NamedLocks are deleted independently even though they are created from the NamedLockManager. The MemLockState can outlive the MemLockManager, but will stay alive as long as any of its MemLocks are alive.

bool net_instaweb::MemLockState::GrabLock

(

MemLock *

lock

)

Attempts to take a lock immediately, returning false if that failed, in which case the caller is expected to set up its timing constraints and schedule it. Note that this doesn't call any callbacks; the caller is responsible for doing that.

bool net_instaweb::MemLockState::IsHeldInOrderedSet

(

MemLock *

lock

)

const

Method to determine whether this lock is in any sets. This is used for debug-assertions to ensure we don't mutate lock state used for ordering the maps while the lock is in one.

void net_instaweb::MemLockState::RemoveLock

(

MemLock *

lock

)

Called when lock is deleted.

Called by MemLock::~MemLock to let us know it doesn't exist anymore. When the last lock is removed, the MemLockState is deleted.

void net_instaweb::MemLockState::ScheduleLock

(

MemLock *

lock

)

Adds a lock to the schedule maps. This happens when a lock is requested. Note that this can directly call lock Run/Cancel if they are due.

void net_instaweb::MemLockState::StealLock

(

MemLock *

lock

)

Steals the current lock by unlocking it, thus handing it to the next in queue, which must be lock. lock's Run function is called as well, in response to unlocking the current lock.

void net_instaweb::MemLockState::Unlock

(

)

Releases the current lock, wakes up the next pending lock (if any) and calls its Run function.

void net_instaweb::MemLockState::UnscheduleLock

(

MemLock *

lock

)

Removes a lock from the current schedule. This is done when lock is granted or denied.

Friends And Related Function Documentation

friend class MemLockManager

friend

To allow the manager to construct

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

• pagespeed/kernel/util/mem_lock_state.h