Memory object pretenuring

Patent metadata

Field	Value
Publication number	US-9507713-B1
Application number	US-201414492845-A
Country	US
Kind code	B1
Filing date	Sep 22, 2014
Priority date	Sep 22, 2014
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A computer-implemented method can include receiving a set of software instructions for execution by a computing device and compiling the set of software instructions to generate a set of executable instructions. The compiling can include identifying a first memory object allocation instruction. The method can also include executing the set of executable instructions, where the executing includes allocating, in a young garbage collection generation, a plurality of memory objects with the first memory object allocation instruction. The method can further include determining a survival rate of the plurality of memory objects allocated by the first memory object allocation instruction. Responsive to the survival rate being larger than a survival rate threshold, the method can include replacing, in the set of executable instructions, the first memory object allocation instruction with a second memory object allocation instruction that is configured to directly allocate memory objects in an old garbage collection generation.

First claim

What is claimed is:

1. A computer-implemented method comprising:
receiving, at a computing device, a set of software instructions for execution by the computing device;
compiling the set of software instructions to generate a set of executable instructions, the compiling including identifying a first memory object allocation instruction;
executing, by the computing device, the set of executable instructions, the executing including allocating, in a young garbage collection generation, a plurality of memory objects with the first memory object allocation instruction;
determining a survival rate of the plurality of memory objects allocated by the first memory object allocation instruction;
determining a count of a number of memory objects allocated by the first memory allocation instruction; and
responsive to the survival rate being larger than a survival rate threshold and the count of the number of memory objects allocated by the first memory allocation instruction being larger than an activity rate threshold, replacing, in the set of executable instructions, the first memory object allocation instruction with a second memory object allocation instruction that is configured to directly allocate memory objects in an old garbage collection generation.

2. The computer-implemented method of claim 1 , wherein:
the compiling the set of software instructions to generate the set of executable instructions is performed by a first compiler of the computing device; and
the replacing the first memory allocation instruction with the second memory allocation instruction is performed by a second compiler of the computing device.

3. The computer-implemented method of claim 1 , further comprising:
responsive to the identifying the first memory allocation instruction, allocating a bookkeeping memory object configured to maintain the count of the number of memory objects allocated by the first memory object allocation instruction and maintain a count of a number of memory objects allocated by the first memory object allocation instruction that are active during a garbage collection process, the survival rate being determined based on the count of allocated memory objects and the count of memory objects that are active during the garbage collection process.

4. The computer-implemented method of claim 3 , wherein allocating an object of the plurality of memory objects includes allocating a shadow object including a pointer to the bookkeeping memory object, the shadow object being used, during the garbage collection process, to update the count of memory objects that are active during the garbage collection process.

5. The computer-implemented method of claim 3 , further comprising, after replacing the first memory allocation instruction with the second memory allocation instruction, resetting, for a third memory allocation instruction, a count of allocated memory objects and a count of active memory objects.

6. The computer-implemented method of claim 1 , further comprising:
determining, by the computing device, that a survival rate of old garbage collection generation memory objects associated with the set of executable instructions is below an old generation survival rate threshold; and
responsive to the determination that the survival rate of the old garbage collection generation memory objects is below the old generation survival rate threshold, replacing the second memory allocation instruction with the first memory allocation instruction.

7. The computer-implemented method of claim 1 , further comprising:
responsive to the survival rate being less than or equal to the survival rate threshold, replacing, in the set of executable instructions, the first memory object allocation instruction with a second memory object allocation instruction that is configured to directly allocate memory objects in the young garbage collection generation.

8. A non-transitory recordable storage medium having instructions recorded and stored thereon, the instructions, when executed by a computing device, cause the computing device to:
receive a set of software instructions for execution by the computing device;
compile the set of software instructions to generate a set of executable instructions, the compiling including identifying a first memory object allocation instruction;
execute the set of executable instructions, the executing including allocating, in a young garbage collection generation, a plurality of memory objects with the first memory object allocation instruction;
determine a survival rate of the plurality of memory objects allocated by the first memory object allocation instruction;
determine a count of a number of memory objects allocated by the first memory allocation instruction; and
responsive to the survival rate being larger than a survival rate threshold and the count of the number of memory objects allocated by the first memory allocation instruction being larger than an activity rate threshold, replace, in the set of executable instructions, the first memory object allocation instruction with a second memory object allocation instruction that is configured to directly allocate memory objects in an old garbage collection generation.

9. The non-transitory recordable storage medium of claim 8 , wherein:
the compiling the set of software instructions to generate the set of executable instructions is performed by a first compiler of the computing device; and
the replacing the first memory allocation instruction with the second memory allocation instruction is performed by a second compiler of the computing device.

10. The non-transitory recordable storage medium of claim 8 , wherein the instructions, when executed by the computing device, further cause the computing device to:
responsive to the identifying the first memory allocation instruction, allocate a bookkeeping memory object configured to maintain the count of the number of memory objects allocated by the first memory object allocation instruction and maintain a count of a number of memory objects allocated by the first memory object allocation instruction that are active during a garbage collection process, the survival rate being determined based on the count of allocated memory objects and the count of memory objects that are active during the garbage collection process.

11. The non-transitory recordable storage medium of claim 10 , wherein allocating an object of the plurality of memory objects includes allocating a shadow object including a pointer to the bookkeeping memory object, the shadow object being used, during the garbage collection process, to update the count of memory objects that are active during the garbage collection process.

12. The non-transitory recordable storage medium of claim 10 , wherein the instructions, when executed by the computing device, further cause the computing device to, after replacing the first memory object allocation instruction with the second memory object allocation instruction, reset, for a third memory object allocation instruction, a count of allocated memory objects and a count of active memory objects.

13. The non-transitory recordable storage medium of claim 8 , wherein the instructions, when executed by the computing device, further cause the computing device to:
determine that a survival rate of old garbage collection generation memory objects associated with the set of executable instructions is below an old generation survival rate threshold; and
responsive to the determination that the survival rate of the old garbage collection generation memory objects is below the old generation survival rate threshold, replace the second memory allocatio

Assignees

• Google Inc

Inventors

• Payer Hannes
• Clifford Daniel
• Stanton Michael Vincent
• Meurer Benedikt

Classifications

• G06F12/0276 Primary

  Generational garbage collection · CPC title

• G06F2212/1016

  Performance improvement · CPC title

• G06F2212/702

  Conservative garbage collection · CPC title

• G06F12/0253 Primary

  Garbage collection, i.e. reclamation of unreferenced memory · CPC title