US 9,032,410 B1Granted

Non-precise garbage collection in non-cooperative systems

AssigneeXamarin Inc.

InventorsRodrigo Kumpera, Miguel de Icaza

Life of this patent

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Abstract

Embodiments are directed towards garbage collection for an application running on a non-cooperative target platform. Where the garbage collection optimistically manages thread state for transitions to and from native and managed code and that some threads are suspended while others are left executing during garbage collection. When a characteristic of the native code call indicates that a duration of the native code call may exceed a defined duration, state information for the thread may be updated to transition the thread to the unmanaged code environment. When a garbage collection event occurs, thread state information is updated to communicate suspend requests to the threads. Then the runtime may wait for each thread in the managed code environment to be reach a safe state before garbage collection may commence.

Claims30

Dependent claims

A method for managing memory for an application using a computer, wherein the computer performs actions, including:

when at least one thread of a plurality of threads encounters a native code call during the execution of the application in a managed code environment, further actions are performed, including:
determining at least one characteristic of the native code call based in part on configuration information that is associated with a target platform for the application;
when the at least one characteristic of the native code call indicates that a duration of the native code call exceeds a defined duration threshold, updating at least state information for the at least one thread to at least indicate that the at least one thread is executing in an unmanaged code environment;
and
when the native code call completes, updating the state information for the at least one thread to at least indicate that the at least one thread is executing in the managed code environment;
and
when a garbage collection event occurs, further actions are performed, including:
updating state information for each of the plurality of threads to communicate a suspend request to the plurality of threads;
waiting for each thread of the plurality of threads that is executing in the managed code environment to become safe for garbage collection;
and
when each thread in the managed code environment is safe for garbage collection, executing one or more garbage collection actions to manage the memory for the application.

8 more elements

A system for managing memory for an application, comprising:

a computer, including:
a transceiver for communicating over the network;
a memory for storing at least instructions;
and
a processor device that is operative to execute instructions that enable actions, including:
when at least one thread of a plurality of threads encounters a native code call during the execution of the application in a managed code environment, further actions are performed, including:
determining at least one characteristic of the native code call based in part on configuration information that is associated with a target platform for the application;
when the at least one characteristic of the native code call indicates that a duration of the native code call exceeds a defined duration threshold, updating at least state information for the at least one thread to at least indicate that the at least one thread is executing in an unmanaged code environment;
and
when the native code call completes, updating the state information for the at least one thread to at least indicate that the at least one thread is executing in the managed code environment;
and
when a garbage collection event occurs, further actions are performed, including:
updating state information for each of the plurality of threads to communicate suspend request to the plurality of threads:
waiting for each thread of the plurality of threads that is executing in the managed code environment to become safe for garbage collection;
and
when each thread in the managed code environment is safe for garbage collection, executing one or more garbage collection actions to manage the memory for the application;
and
a development computer, including:
a transceiver for communicating over the network;
a memory for storing at least instructions;
and
a processor device that is operative to execute instructions that enable actions, including:
compiling a machine code version of the application.

20 more elements

A computer for managing memory for an application, comprising:

a transceiver for communicating over the network;
a memory for storing at least instructions;
and
a processor device that is operative to execute instructions that enable actions, including:
when at least one thread of a plurality of threads encounters a native code call during the execution of the application in a managed code environment, further actions are enabled, including:
determining at least one characteristic of the native code call based in part on configuration information that is associated with a target platform for the application;
when the at least one characteristic of the native code call indicates that a duration of the native code call exceeds a defined duration threshold, updating at least state information for the at least one thread to at least indicate that the at least one thread is executing in an unmanaged code environment;
and
when the native code call completes, updating the state information for the at least one thread to at least indicate that the at least one thread is executing in the managed code environment;
and
when a garbage collection event occurs, further actions are performed, including:
updating state information for each of the plurality of threads to communicate suspend request to the plurality of threads;
waiting for each thread of the plurality of threads that is executing in the managed code environment to become safe for garbage collection;
and
when each thread in the managed code environment is safe for garbage collection, executing one or more garbage collection actions to manage the memory for the application.

12 more elements

A processor readable non-transitive storage media that includes instructions for managing memory for an application, wherein a computer that executes at least a portion of the instructions is enabled to perform actions, comprising:

when at least one thread of a plurality of threads encounters a native code call during the execution of the application in a managed code environment, further actions are performed, including:
determining at least one characteristic of the native code call based in part on configuration information that is associated with a target platform for the application;
when the at least one characteristic of the native code call indicates that a duration of the native code call exceeds a defined duration threshold, updating at least state information for the at least one thread to at least indicate that the at least one thread is executing in an unmanaged code environment;
and
when the native code call completes, updating the state information for the at least one thread to at least indicate that the at least one thread is executing in the managed code environment;
and
when a garbage collection event occurs, further actions are performed, including:
updating state information for each of the plurality of threads to communicate suspend request to the plurality of threads;
waiting for each thread of the plurality of threads that is executing in the managed code environment to become safe for garbage collection;
and
when each thread in the managed code environment is safe for garbage collection, executing one or more garbage collection actions to manage the memory for the application.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/463,440Filed 19 Aug 2014
Granted: 12 May 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G06F 12/0253
Free address space management: garbage collection, i.e. reclamation of unreferenced memory
G06F 8/70
Arrangements for software engineering: software maintenance or management
G06F 9/485
By program, e.g. task dispatcher, supervisor, operating system: task life-cycle, e.g. stopping, restarting, resuming execution
G06F 9/5022
The resources being hardware resources other than CPUs, Servers and Terminals: mechanisms to release resources