JPH03116260A - Spin lock system for multiprocessor system - Google Patents

Abstract

PURPOSE:To prevent a sinking phenomenon due to the lock conflict of a specific CPU by giving immediately the reservation numbers to the CPUs requesting the occupation of the resources and controlling the order of CPUs for reception of resources based on those reservation numbers. CONSTITUTION:When a program 11 occupies the resources, the program 11 carries out a lock process 12 to the resources. That is, a reservation number 52 of the lock field corresponding to the resources is acquired by a reservation number acquiring means 14. At the same time, the reservation number is advanced by one step on the field. Then the reservation number obtained previously by a lock right acquiring means 15 is kept waiting in a spin (loop) until the number is coincident with a right number 53. When an unlock process 13 is carried out to the resources, the number 53 of the corresponding lock field is advanced by a step by a lock right transfer means 16. Then the resources are transferred to the CPU having the next reservation number. Thus it is possible to evade such a sinking phenomenon of a CPU where the lock of a specific CPU is kept waiting forever.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spinlock method in a memory sharing type [tightly coupled co-multiprocessor system].

[Conventional technology] In the conventional spinlock method, the test setting of the lock bite by TS (test and set) operation is
Locking was performed repeatedly until E (success) was obtained, and TRUE was set in the lock byte to unlock.

[Problems to be Solved by the Invention] In the conventional spinlock method, if a CPU locks a resource and other CPUs lock the resource while it is occupying the resource, when the resource is unlocked, the next Nido C
It is not determined whether the PU can occupy resources. For this reason,
In some cases, locking a particular CPU may be kept waiting indefinitely. This is called CPU sinking.

[Means for Solving the Problems] The spinlock system of the present invention includes a means for acquiring a reservation number that determines the order in which resources can be occupied, a lock right acquisition means for acquiring the right to occupy the resource according to the reservation number, and a means for acquiring the right to occupy the resource, and a means for acquiring the right to occupy the resource according to the reservation number. It is characterized by having a lock right transfer means to release the lock.

[Example] Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which lock processing 12
The reservation number acquisition means 14 and the lock right acquisition means 15 occupy resources, and the unlock processing 13 releases the resources locked by the lock right transfer means 16.

FIG. 2 shows one embodiment of the reservation number acquisition means 14.

Obtain the reservation number for the target resource and at the same time add 1 to the reservation number.
Add it up. In this embodiment, this concurrency is guaranteed by a spin lock based on conventional TS operation.

FIG. 3 shows an embodiment of the lock right acquisition means 15, which spins and waits until the exclusive right number of the target resource matches the acquired reservation number.

FIG. 4 shows an embodiment of the lock right transfer means for the lock right acquisition means 15 shown in FIG.

When releasing an occupied resource, change the exclusive right number of the target resource to 1.
Add and transfer the rights to the next person.

FIG. 5 shows a lock field (management table) for each exclusive resource in the two embodiments, and as described above, it consists of a reservation number, its lock byte, and an exclusive right number. The initial value may be the reservation number minus the right number.

Next, the operation will be explained.

In FIG. 1, when the program 11 occupies a certain resource,
Lock processing 12 is performed on the resource.

In the lock processing, the reservation number acquisition means 14 obtains the reservation number 52 of the lock field (FIG. 5) corresponding to the resource, and simultaneously increments the reservation number on the field by one step. In other words, the person who obtains the reservation number first will be given a number incremented by 1. Next, it spins (loop) and waits until the reservation number previously obtained by the lock right acquisition means 15 matches the right number 53 of the lock field.

If they match, the resource occupancy is determined to be complete and the locking process ends.

When releasing the resources occupied by the program 11 in this way, an unlock process 13 is performed for the resources.
I do. Unlock process 13 is a lottery right transfer method 1
6 to the corresponding Lockfield right number 53 to 1
By incrementing, the resource is given over to the CPU with the next reservation number.

[Effects of the Invention] As described above, the present invention immediately gives a reservation number to a CPU that requests resource occupancy, and provides the CPU with the resource in accordance with the reservation number.
Since the order of the CPUs is controlled, there is an effect that no slump due to lock contention of a specific CPU occurs.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a flowchart of the reservation number acquisition means shown in FIG. 1, and FIG. 3 is a flowchart of the right acquisition means shown in FIG. 1. FIG. 4 is a flowchart of the lock right transfer means shown in FIG. 1, and FIG. 5 is a diagram of a table (lock field) for managing the order of resource occupancy according to an embodiment of the present invention. In the figure, 14 is a reservation number acquisition means, 15 is a lock right acquisition means, and 16 is a lock right transfer means. Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1) In a memory sharing type [tightly coupled] multiprocessor system, a reservation number acquisition means that determines the order in which lock resources can be occupied, and a lock right acquisition means that acquires resource occupation rights based on the reservation number. A spinlock method in a multiprocessor system characterized by using a lock operation configured by a lock operation and an unlock operation configured by a lock right transfer means to release occupied resources. 2) In the spin lock method according to claim 1, the reservation number acquisition means obtains a reservation number for the target resource and at the same time adds 1 to the reservation number and sets the reservation number, and the lock right acquisition means , a spin lock method in a multiprocessor system, characterized in that the method waits until the exclusive right number of the target resource matches the acquired reservation number. 3) A multiprocessor according to claim 1, wherein the lock right transfer means, when releasing a resource, increments the resource's exclusive right number by 1 and transfers the exclusive right to the next one. Spinlock method in the system.