Block Busting

• VIM의 tags 파일에 tagging된 함수명으로 파일열기
• 사용법은 아래와 같다. 

•    $ vim -t <filename>

  • 만약에 $HOME/user/tistory/test/ 경로에 *.c 파일이 수십개 있다고 가정한 상태에서
  • 함수 이름만 알고 있을 경우, 
  • grep 명령으로 찾아서 해당되는 파일을 열어도 되지만, 
  • tags 파일이 존재하는 경우라면
  • vim -t 옵션으로 간편하게 열 수 있다. 
  • 쓰고보니... grep 한번 덜 할 수 있는 장점이 있다. ㅋ

• VIM의 읽기 전용 기능 (read only)
• 사용법은 아래와 같다. 

•    $ vim -R <filename>

• VIM의 다중파일 열기 기능 (한번에 여러개 파일 열기)
• 사용법은 아래와 같다. 옵션이 3가지가 있다.  (-o, -O 옵션뒤에 숫자는 파일 개수)
• -o3 옵션 : 파일 3개를 수평분할로 보여줌
• -O3 옵션 : 파일 3개를 수직분할로 보여줌
• -p 옵션 : vim 윈도우모드로 보여줌

•      $ vim -o3 f1.txt f2.txt f3.txt
• 
  

     $ vim -O3 f1.txt f2.txt f3.txt

  
  
      $ vim -p f1.txt f2.txt f3.txt

• VIM의 DIFF 기능 (창이 분할되서 보이는데 편함)
• 사용법은 아래처럼 단순하다. (둘중에 아무거나 편한걸 사용하면 됨)
•    vimdiff file1 file2 [file3 [file4]]
•    vim -d file1 file2 [file3 [file4]]

예를들어서 vim -d main.c main1.c main2.c 명령을 수행하면 아래같이 나옴.

2.1 Timer Service

The Timer Service provides a mechanism by which client processes get notified

when a timer expires. A timer is a logical object that is dynamically created and represents

either absolute time or a duration.

The Timer Service provides two types of timers: single event timers and periodic timers.

Single event timers will expire once and are deleted after notification. Periodic

timers will expire each time a specified duration is reached, and the process is notified

about the expirations. Periodic timers have to be explicitly deleted by invoking the

saTmrTimerCancel() function.

2.1 Naming Service

The Naming Service provides a mechanism by which human-friendly names are

associated with (‘bound to’) objects so that these objects can be looked up given their names. 

The objects typically represent service access points, communication endpoints

and other resources that provide some sort of service.

The Naming Service imposes neither a specific layout nor a convention on either the names (UTF-8 encoding assumed) or the objects to which they are bound. 

It allows the users of the service to select and use their own naming schema without assuming any specific hardware or logical software configuration. 

The clients of the Naming Service are expected to understand the structure, layout and semantics of the object bindings they intend to store inside and retrieve from the service.

The Naming Service caters to two categories of clients

• Service provider - Software entities that wish to advertise objects bound to a

name.

• Service user - Software

2.1 Lock Service

The Lock Service is a distributed lock service, which is intended for use in a cluster where processes in different nodes1 might compete with each other for access to a shared resource.

The Lock Service provides entities called lock resources, which application processes use to coordinate access to shared resources.

The Lock Service provides a simple lock model supporting two locking modes for exclusive access and shared access. 

All implementations must offer synchronous and asynchronous calls, lock timeout, trylock, and lock wait notifications. 

Implementations may optionally offer the additional features of deadlock detection and lock orphaning. 

A Lock Service interface allows an application to query for support for one or more of the optional features. 

If an application depends on one of the optional features for proper operation, it should use this interface to check whether the feature is provided. 

Maximum portability is achieved by avoiding use of the optional features.

However, because they offer powerful functionality, it may make sense to take advantage of them when they are available.

The locks provided by the Lock Service are not recursive. 

Thus, claiming one lock does not implicitly claim another lock; rather, each lock must be claimed individually.

2.1 Checkpoint Service

The Checkpoint Service provides a facility for processes to record checkpoint dataincrementally, which can be used to protect an application against failures. 

When recovering from fail-over or switch-over situations, the checkpoint data can be retrieved, and execution can be resumed from the state recorded before the failure.

Checkpoints are cluster-wide entities that are designated by unique names. 

A copy of the data stored in a checkpoint is called a checkpoint replica; for performance reasons,a checkpoint replica is typically stored in main memory rather than on disk. A checkpoint may have several checkpoint replicas stored on different nodes1 in the cluster to protect it against node failures.

To avoid accumulation of unused checkpoints in the system, checkpoint replicas

have a retention time. 

When a checkpoint has not been opened by any process for the duration of the retention time, the Checkpoint Service automatically deletes the checkpoint.