Apple Inc.

Shantonu Sen

Michael R Smith

Dallas Blake De Atley

Joshua P De Cesare

Russell Alexader Blaine

John Andrew Wright

Matthew Reda

Daniel Allen Chimene

James Michael Magee

Cyril De La Cropte De Chanterac

John Gregory Dorsey

Bryan R Hinch

Craig Michael Federighi

Matthew John Byom

Guy Leslie Tribble

Kevin James Van Vechten

Daniel Andreas Steffen

Kevin R Walker

Daniel Heller

Vishal Patel

Olivier Cozelle

Oliver Cozette

A method and an apparatus for establishing an operating environment by certifying a code image received from a host over a communication link are described. The code image may be digitally signed through a central authority server. Certification of the code image may be determined by a fingerprint embedded within a secure storage area such as a ROM (read only memory) of the portable device based on a public key certification process. A certified code image may be assigned a hash signature to be stored in a storage of the portable device. An operating environment of the portable device may be established after executing the certified code.

Securely recovering a computing device

In one embodiment, an application programming interface (API) is defined that enables a thread scheduler to communicate thread information to the CPU performance controller when dispatching a thread to a processor or processor core. When dispatching a thread, the scheduler may communicate thread information including thread state information, a general 'importance' of the thread as defined by a priority level and/or quality of service (QoS) classification, a measurement of the scheduler dispatch latency for the thread, or architectural information regarding the instructions within the thread, such as whether the thread is contains 64-bit or 32-bit instructions. The performance controller can use the information provided by the scheduler to make performance control decisions for the processor cores within the system.

Scheduler and CPU performance controller cooperation

Disclosed herein are systems, methods, and computer-readable media directed to scheduling threads in a multi-processing environment that can resolve a priority inversion. Each thread has a scheduling state and a context. A scheduling state can include attributes such as a processing priority, classification (background, fixed priority, real-time), a quantum, scheduler decay, and a list of threads that may be waiting on the thread to make progress. A thread context can include registers, stack, other variables, and one or more mutex flags. A first thread can hold a resource with a mutex, the first thread having a low priority. A second thread having a scheduling state with a high priority can be waiting on the resource and may be blocked behind the mutex held by the first process. A scheduler can execute the context of the lower priority thread using the scheduler state of the second, higher priority thread. More than one thread can be waiting on the resource held by the first thread. A 'pusher list' of threads that are waiting on the first thread can be associated with the first thread. The scheduler can use the pusher list to identify threads that need the first thread to make progress until the first thread releases the resource and mutex. Then, the scheduler can use the pusher list to identify threads that are now runnable and make immediate use of the resource.

Hand-off scheduling

Techniques for scheduling threads for execution in a data processing system are described herein. According to one embodiment, in response to a request for executing a thread, a scheduler of an operating system of the data processing system accesses a global run queue to identify a global run entry associated with the highest process priority. The global run queue includes multiple global run entries, each corresponding to one of a plurality of process priorities. A group run queue is identified based on the global run entry, where the group run queue includes multiple threads associated with one of the processes. The scheduler dispatches one of the threads that has the highest thread priority amongst the threads in the group run queue to one of the processor cores of the data processing system for execution.

Multiple process scheduling of threads using process queues

A method and an apparatus for establishing an operating environment by certifying a code image received from a host over a communication link are described. The code image may be digitally signed through a central authority server. Certification of the code image may be determined by a fingerprint embedded within a secure storage area such as a read only memory (ROM) of the portable device based on a public key certification process. A certified code image may be assigned a hash signature to be stored in a storage of the portable device. An operating environment of the portable device may be established after executing the certified code.

A method and an apparatus for activity based execution scheduling are described. Activities may be tracked among a plurality of threads belonging to a plurality of processes running in one or more processors. Each thread may be associated with one of the activities. Each activity may be associated with one or more of the threads in one or more of the processes for a data processing task. The activities may be ordered by a priority order. A group of the threads may be identified to be associated with a particular one of the activities with highest priority based on the priority order. A thread may be selected from the identified threads for next scheduled execution in the processors.

Method and apparatus for activity based execution scheduling

A method and apparatus of a device that captures a stackshot of an executing process is described. In an exemplary embodiment, the device detects an interrupt of the process occurring during the execution of the process, where the process execution can be in a kernel space and user space, and the interrupt occurs during the user space. The device further determines whether to capture a stackshot during the interrupt using a penalty function. If the stackshot is to be captured, the device captures the stackshot and saves the stackshot.

Microstackshots

Methods, machine-readable tangible storage media, and data processing systems that enable a debug host device to acquire memory dump information from a debug target device after the target device suffers an unrecoverable system malfunction are disclosed. In one embodiment, data in the volatile memory on a debug target device is accessed via a hardware integrated debug framework, which is also used to access data on a nonvolatile electronically erasable semiconductor memory of a debug target device, and one or more registers of one or more processors on a debug target device, and a core dump is created on the debug host device.

Growing community of inventors

Cupertino, CA, United States of America

Shantonu Sen