io.servicetalk.concurrent.internal

Class FlowControlUtil

java.lang.Object

io.servicetalk.concurrent.internal.FlowControlUtil

public final class FlowControlUtil
extends java.lang.Object

A set of utility methods for safe math operations to prevent overflow.

Method Summary

Modifier and Type	Method and Description
static <T> int	addWithOverflowProtection(java.util.concurrent.atomic.AtomicIntegerFieldUpdater<T> updater, T owner, int amount) Increment an integer referred by AtomicIntegerFieldUpdater atomically and saturate to Integer.MAX_VALUE if overflow occurs.
static <T> long	addWithOverflowProtection(java.util.concurrent.atomic.AtomicLongFieldUpdater<T> updater, T owner, long amount) Increment a long referred by AtomicLongFieldUpdater atomically and saturate to Long.MAX_VALUE if overflow occurs.
static int	addWithOverflowProtection(int x, int y) Adds two positive ints and returns Integer.MAX_VALUE if overflow occurs.
static long	addWithOverflowProtection(long x, long y) Adds two positive longs and returns Long.MAX_VALUE if overflow occurs.
static long	addWithOverflowProtectionIfGtEqNegativeOne(long x, long y) If x is >=-1 this method behaves the same as addWithOverflowProtection(long, long).
static int	addWithOverflowProtectionIfNotNegative(int x, int y) If x is non-negative this method behaves the same as addWithOverflowProtection(int, int).
static long	addWithOverflowProtectionIfNotNegative(long x, long y) If x is non-negative this method behaves the same as addWithOverflowProtection(long, long).
static int	addWithOverflowProtectionIfPositive(int x, int y) If x is positive this method behaves the same as addWithOverflowProtection(int, int).
static long	addWithOverflowProtectionIfPositive(long x, long y) If x is positive this method behaves the same as addWithOverflowProtection(long, long).
static long	subtractIfPositive(long x, long y) Subtract y from x if x is positive.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

addWithOverflowProtectionIfGtEqNegativeOne

public static long addWithOverflowProtectionIfGtEqNegativeOne(long x,
                                                              long y)

If x is >=-1 this method behaves the same as addWithOverflowProtection(long, long). If x is <-1 then x is returned.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

The result of x+y or Long.MAX_VALUE if overflow occurs, or x if x<-1.

addWithOverflowProtectionIfNotNegative

public static long addWithOverflowProtectionIfNotNegative(long x,
                                                          long y)

If x is non-negative this method behaves the same as addWithOverflowProtection(long, long). If x is negative then x is returned.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

The result of x+y or Long.MAX_VALUE if overflow occurs, or x if x is negative.

addWithOverflowProtectionIfNotNegative

public static int addWithOverflowProtectionIfNotNegative(int x,
                                                         int y)

If x is non-negative this method behaves the same as addWithOverflowProtection(int, int). If x is negative then x is returned.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

The result of x+y or Integer.MAX_VALUE if overflow occurs, or x if x is negative.

addWithOverflowProtectionIfPositive

public static int addWithOverflowProtectionIfPositive(int x,
                                                      int y)

If x is positive this method behaves the same as addWithOverflowProtection(int, int). If x is negative or zero then x is returned.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

The result of x+y or Integer.MAX_VALUE if overflow occurs, or x if x is negative.

addWithOverflowProtectionIfPositive

public static long addWithOverflowProtectionIfPositive(long x,
                                                       long y)

If x is positive this method behaves the same as addWithOverflowProtection(long, long). If x is negative or zero then x is returned.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

The result of x+y or Long.MAX_VALUE if overflow occurs, or x if x is negative.

subtractIfPositive

public static long subtractIfPositive(long x,
                                      long y)

Subtract y from x if x is positive.

Parameters:

x - first value (may be negative).

y - second value (should be positive).

Returns:

the result of x-y if x>0, or x.

addWithOverflowProtection

public static long addWithOverflowProtection(long x,
                                             long y)

Adds two positive longs and returns Long.MAX_VALUE if overflow occurs.

Parameters:

x - first value (should be positive).

y - second value (should be positive).

Returns:

The result of x+y or Long.MAX_VALUE if overflow occurs.

addWithOverflowProtection

public static int addWithOverflowProtection(int x,
                                            int y)

Adds two positive ints and returns Integer.MAX_VALUE if overflow occurs.

Parameters:

x - first value (should be positive).

y - second value (should be positive).

Returns:

The result of x+y or Integer.MAX_VALUE if overflow occurs.

addWithOverflowProtection

public static <T> int addWithOverflowProtection(java.util.concurrent.atomic.AtomicIntegerFieldUpdater<T> updater,
                                                T owner,
                                                int amount)

Increment an integer referred by AtomicIntegerFieldUpdater atomically and saturate to Integer.MAX_VALUE if overflow occurs.

Type Parameters:

T - Type of the owner.

Parameters:

updater - AtomicIntegerFieldUpdater used to atomically increment.

owner - Owner class of AtomicIntegerFieldUpdater.

amount - Amount to increment.

Returns:

Value of int referred by AtomicIntegerFieldUpdater after the increment.

addWithOverflowProtection

public static <T> long addWithOverflowProtection(java.util.concurrent.atomic.AtomicLongFieldUpdater<T> updater,
                                                 T owner,
                                                 long amount)

Increment a long referred by AtomicLongFieldUpdater atomically and saturate to Long.MAX_VALUE if overflow occurs.

Type Parameters:

T - Type of the owner.

Parameters:

updater - AtomicLongFieldUpdater used to atomically increment.

owner - Owner class of AtomicLongFieldUpdater.

amount - Amount to increment.

Returns:

Value of long referred by AtomicLongFieldUpdater after the increment.