Protocol for coordinating the distribution of shared memory

• US 7,240,169 B2
• Filed: 01/18/2002
• Issued: 07/03/2007
• Est. Priority Date: 02/04/1999
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Dennie, Shaun
• Primary Examiner(s): Thai; Tuan V.
• Application Number:
  US10/050,774
• Publication Number:
  US 20020059503A1
• Time in Patent Office: 1,992 Days
• Field of Search: 711/100, 711/130, 711/148, 711/153, 711/154, 711/158, 711/163, 711/170, 711/147
• US Class Current: 711/153
• CPC Class Codes: G06F 9/5016 the resource being the memory

Abstract

Methods, systems, and articles of manufacture consistent with the present invention coordinate distribution of shared memory to threads of control executing in a program by using a cooperative synchronization protocol. The protocol serializes access to memory by competing threads requesting assignment of memory space, while allowing competing threads that have already been assigned memory space, to share access to the memory. A designated area of memory assigns the memory to requesting threads. The protocol is an application level entity and therefore does access the operating system to serialize the memory allocation process.

Claims

1. A system for assigning blocks of memory, the system comprising:

an area of a memory designated for coordinating the assignment of the memory to one or more threads requiring access to the memory, wherein the area includes usage information reflecting usage of the memory; and

a processor for performing a protocol for serializing access to the memory by the one or more threads based on the usage information, wherein the protocol allows a first thread to access a first designated block of the memory while another thread requests and secures access to another block of the memory.

2. The system of claim 1, wherein the another thread secures access to the another block of memory based on a token obtained from the area of memory that was previously used by the thread to secure access to the designated block of memory.

3. The system of claim 1, wherein the size of the designated block of memory is determined by a user.

4. The system of claim 1, wherein the another designated block of memory is adjacent to the designated block of memory.

5. A method, comprising:

allocating to a first process, without accessing an operating system, a first block of a memory that has a size designated by a user; and

allocating to a second process, without accessing an operating system, a second block of the memory that has a size designated by the user while the first process is accessing the first block of memory.

6. The method of claim 5, wherein the allocating of the first and second blocks of memory to the first and second processes, respectively, is based on a token obtained from a designated area of the memory.

7. The method of claim 6, wherein the first and second blocks of memory are consecutive blocks of memory.

8. The method of claim 6, wherein allocating the first block of memory comprises:

incrementing a value that reflects a location in the memory corresponding to the first block of memory.

9. The method of claim 8, wherein allocating the second block of memory comprises:

determining the second block of memory based on the incremented value.