Instruments of Xcode
Xcode仪表是一个性能分析、测试工具，动态跟踪和剖析OS X和iOS代码。灵活有力的跟踪一个过程，收集数据，检查收集回来的数据。通过这种方式，仪器帮助你理解用户应用和操作系统的表现。Instruments is a performance-analysis and testing tool for dynamically tracing and profiling OS X and iOS code. It is a flexible and powerful tool that lets you track a process, collect data, and examine the collected data. In this way, Instruments helps you understand the behavior of both user apps and the operating system.
剖析模板: Blank, Activity Monitor, Allocations, Automation, Cocoa Layout, Core Animation, Core Data, Counters, Dispatch, Energy Diagnostics, File Activity, GPU Driver
Blank: A blank trace document that can be customized with instruments from the Library.
Activity Monitor: Monitors processes' CPU, memory, disk, and network usage statistics.
Allocations: Tracks a process' anonymous virtual memory and heap, providiing class names and optionally retain/release histories for objects.
Automation: This template executes a script which simulates UI interaction for an iOS application launched from Instruments.
Core Layout: Observes changes to NSLayoutConstraint objects to help determine when and where a layout constraint went awry.
Core Animation: This template measures application graphics performance as well as CPU usage of a process via time profiling.
Core Data: This template traces Core Data filessystem activity, including fetches, cache misses, and saves. To customize, place items from the Library window onto the Instruments list, then use the inspector to adjust the ...
Counters: Collects performance monitor counter (PMC) events using time or event based sampling methods.
Dispatch: This template monitors dispatch queue activity, and records block invocations and their duration.
Energy Diagnostics: This template provides diagnostics regarding energy usage as well as basic on/off state of major device components.
File Activity: This template monitors file and directory activity, including file open/close calls, file permission modifications, directory createion, file moves, etc.
GPU Driver: Measures GPU driver statistics and samples active CPU usage.
Leaks: Measures general memory usage, checks for leaked memory, and provides statistics on object allocations by class as well as memory addresss histories for all active allocations and leaked blocks.
Multicore: This template provides analysis of multicore performance, including thread state, dispatch queues, and block usage.
Network: Analyze how your applications are using TCP/IP and UDP/IP connections using the Connections Instrument.
OpenGL ES Analysis: This template measures and analyzes OpenGL ES activity to detect OpenGL ES correctness and performance problems. It also offers recommendations for addressing these problems.
Sudden Termination: Analyzes sudden termination support of a target process, reporting backtraces for file system accesses and sudden termination enable/disable calls.
System Trace: Provdes comprehensive information about system behavior by showing when threads are sceduled, and showing all their transitions from user into system code via either system calls or memory operations.
System Usage: This template records I/O system activity related to files, sockets, and shared memory for single process launched via instruments. Inputs, outputs, duration, backtrace, calltree, etc. is provided for each call.
Time Profiler: Performs low-overhead time-based sampling of processes running on the system's CPUs.
UI Recorder: Records the user interface events of a process launched from Instruments, which can later be played back while other Instruments are recording. To use, switc to 'Capture' mode to record the events or to 'Drive' mode to replay the events in order to drive the target application's user interface from Instruments.
Zombies: Measures general memory usage while focusing on the detection of over-released 'zombie' objects. Also provides statistics on object allocations by class as well as memory address histories for all active allocations.