Inter-processor exclusive control apparatus for enabling one of a plurality of processors execute an executable unit process

• US 5,630,134 A
• Filed: 03/17/1994
• Issued: 05/13/1997
• Est. Priority Date: 06/11/1993
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Haga, Yutaka
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): BANANKHAH, MAJID A
• Application Number:
  US08/214,308
• Time in Patent Office: 1,153 Days
• Field of Search: 395/650, 395/700, 395/680, 395/676, 364/DIG. 1
• US Class Current: 718/106
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

A multiprocessor system employs an inter-processor exclusive control apparatus. The inter-processor exclusive control apparatus has local areas formed in local memories, respectively, or in a shared memory, to store exclusive control data, as well as a shared area formed in the shared memory, to store exclusive control data. Executable unit processes manipulated by the multiprocessor system are optionally divided into groups that are associated with the local areas, respectively. The local memories are accessible only by the executable unit processes in the corresponding groups. The shared memory is shared by these groups. Each of the local areas manages exclusive requests from the corresponding executable unit processes. The shared area manages exclusive requests from the groups. Since the exclusive requests from the executable unit processes are managed by both the local areas and shared area, the number of accesses to the shared area is decreased because the shared area is accessible only by the groups. As a result, the system achieves exclusive control at high speed.

Claims

1. An inter-processor exclusive control apparatus for enabling one of a plurality of processors to execute an executable unit process to exclusively manipulate a resource or an instruction procedure apart from other executable unit processes executed by the other of said processors, wherein said inter-processor exclusive control apparatus comprises:

a plurality of local areas for managing exclusive control data, formed in a memory shared by said plurality of processors, said plurality of executable unit processes being optionally divided into a plurality of groups that are associated with said plurality of local areas, respectively, exclusive requests from said plurality of executable unit processes in a corresponding one of said plurality of groups being managed by a corresponding one of said plurality of local areas, said plurality of groups of said executable unit processes being further grouped and managed in a tree structure, said further groups being provided with exclusive control data areas, respectively, formed in said shared memories that are accessible only by said further groups, said exclusive control data areas managing exclusive requests from said executable unit processes in the respective groups, execution requests to higher groups being hierarchically transmitted; and

a shared area for managing exclusive control data, formed in said shared memory, said shared area managing exclusive requests from said plurality of groups, thereby decreasing a number of accesses to said shared area by both said local areas and said shared area managing exclusive requests from said executable unit processes and by only said plurality of groups accessing said shared area.

2. An inter-processor exclusive control apparatus as claimed in claim 1, wherein said inter-processor exclusive control apparatus further comprises local memories dedicated to said processors, said local memories are accessible only by the corresponding groups, and said local areas are formed in said local memories, respectively.

3. An inter-processor exclusive control apparatus as claimed in claim 2, wherein said plurality of groups of said executable unit processes are further grouped and managed in a tree structure, said further groups are provided with exclusive control data areas, respectively, formed in said local memories that are accessible only by said further groups, said exclusive control data areas managing exclusive requests from said executable unit processes in the respective groups, execution requests to higher groups being hierarchically transmitted.

4. An inter-processor exclusive control apparatus as claimed in claim 1, wherein:

said executable unit processes are grouped so that an executable unit process in a given group are terminated if a corresponding one of said processors fails;

said local areas are removed or disabled if a corresponding one of said processors fails, said local areas managing exclusive requests from executable unit processes in the respective groups;

said shared area for managing exclusive requests from said groups is formed in said shared memory that is always available even if some of said processors fail;

only said shared area is accessed if one of said processors fails and if said executable unit process group corresponding to said failed processor is holding an exclusive right or has issued an exclusive request, to transfer the exclusive right to another group, or cancel said exclusive request; and

the remaining non-failing processors continuously operate even if some of said processors fail, to eliminate the need of withdrawing management resources related to said failed processors.

5. A multiprocessor system having a plurality of processors, a memory shared by said processors, and an inter-processor exclusive control apparatus for enabling one of said processors to execute an executable unit process to exclusively manipulate a resource or an instruction procedure apart from other executable unit processes executed by the other of said processors, wherein said inter-processor exclusive control apparatus comprises:

a plurality of local areas for managing exclusive control data, formed in said shared memory, said plurality of executable unit processes being optionally divided into a plurality of groups that are associated with said plurality of local areas, respectively, exclusive requests from said plurality of executable unit processes in a corresponding one of said plurality of groups being managed by a corresponding one of said plurality of local areas, said plurality of groups of said executable unit processes being further grouped and managed in a tree structure, said further groups being provided with exclusive control data areas, respectively, formed in said shared memories that are accessible only by said further groups, said exclusive control data areas managing exclusive requests from said executable unit processes in the respective groups, execution requests to higher groups being hierarchically transmitted; and

a shared area for managing exclusive control data, formed in said shared memory, said shared area managing exclusive requests from said plurality of groups, thereby decreasing a number of accesses to said shared area by both said local areas and said shared area managing exclusive requests from said executable unit processes and by only said plurality of groups accessing said shared area.

6. A multiprocessor system as claimed in claim 5, wherein said inter-processor exclusive control apparatus further comprises local memories dedicated to said processors, said local memories are accessible only by the corresponding groups, and said local areas are formed in said local memories, respectively.

7. A multiprocessor system as claimed in claim 6, wherein said plurality of groups of said executable unit processes are further grouped and managed in a tree structure, said further groups are provided with exclusive control data areas, respectively, formed in said local memories that are accessible only by said further groups, said exclusive control data areas managing exclusive requests from said executable unit processes in the respective groups, execution requests to higher groups being hierarchically transmitted.

8. A multiprocessor system as claimed in claim 5, wherein:

said executable unit processes are grouped so that an executable unit process in a given group is terminated if a corresponding one of said processors fails;

said local areas are removed or disabled if a corresponding one of said processors fails, said local areas managing exclusive requests from executable unit processes in the respective groups;

said shared area for managing exclusive requests from said groups is formed in said shared memory that is always available even if some of said processors fail;

only said shared area is accessed if one of said processors fails and if said executable unit process group corresponding to said failed processor is holding an exclusive right or has issued an exclusive request, to transfer the exclusive right to another group, or cancel said exclusive request; and

the remaining non-failing processors continuously operate even if some of said processors fail, to eliminate the need of withdrawing management resources related to said failed processors.