unlocks iphones

operations in the HA environment. Note: The "-B" parameter calls SC _FORCED_OPEN to open the hdisk lock in VG. However, for both SCSI and FC devices, this command unlocks all Luns on the targetaddress of the hdisk. For example, if hdisk0 and hdisk1 are both in fcs0, hdisk0 belongs to datavg, and hdisk1 belongs to testvg, varyonvg-B datavg is used, and hdisk0 and hdisk1 are unlocked. In addition, you can use varyonvg-B to unlock the VG on an AIX host

compress or decompress files while packing and unpackage, tar provides a special feature. This means that tar can call other compression programs, such as gzip and Bzip2, while packaging or unpacking.1) tar calls GzipGzipis a program developed by gnuorganization. The file ending with .gz is the result of gzip compression. The decompress program relative to gzip is gunzip. Use the-Z parameter in tar to call gzip. The following is an example:# Tar-CZF all.tar.gz *. jpgBytes# Tar-xzf all.tar.gzThi

the default value, that is, the common lock. When a thread locks, other threads requesting the lock form a waiting queue and obtain the lock by priority after unlocking. This lock policy ensures the fairness of resource allocation. * PTHREAD_MUTEX_RECURSIVE_NP: Nested lock, which allows the same thread to successfully obtain the same lock multiple times and unlock it through multiple unlocks. For different thread requests, re-compete when the lock th

gzip. The following is an example: # Tar-czf all.tar.gz *. jpgBytes # Tar-xzf all.tar.gzThis command unlocks the generated package. 2) tar call bzip2 Bzip2is a more powerful compression program. The file ending with .bz2 is the result of bzip2 compression. The decompress program relative to bzip2 is bunzip2. Use the-j parameter in tar to call gzip. The following is an example: # Tar-cjf all.tar.bz2 *. jpgBytes # Tar-xjf all.tar.bz2This command

initialize the condition variable cond. When cond_attr is null, the default attribute is used. The threads implementation condition variable does not support attributes, so the cond_attr parameter is ignored.Variables of the pthread_cond_t type can also be statically initialized using the pthread_cond_initializer constant.Pthread_cond_signal enables a thread in the thread waiting on the condition variable to start again. If there is no waiting thread, nothing will be done. If multiple threads a

files in the all.tar package.-X is used to unlock the file. The above is the most basic usage of tar. To help you compress or decompress the packageFile, tar provides a special feature. This means that tar can call other pressures while packaging or unpacking.Program shrinking, such as calling gzip and Bzip2. 1) tar calls Gzip Gzipis a program developed by gnuorganization. The file ending with .gz is the result of gzip compression. And GzipThe relative decompression program is gunzip. Use the-Z

can handle the deadlock accordingly. In addition, different mutex lock types have different deadlocks, but the most important thing is that programmers should pay attention to this in programming. 4.3 condition VariablesThe previous section describes how to use mutex to share and communicate data between threads. One obvious drawback of mutex is that it has only two States: Lock and non-lock. Conditional variables make up for the lack of mutex lock by allowing the thread to block and wait for a

number of locks for the current thread.IsLocked: Determine if lock is added.Getqueuelength: Gets the length of the wait queue.The read-write lock Reentrantreadwritelockreentrantreadwritelock is a mixed lock that distinguishes between read and write locks, which is a shared lock, and a write lock is an exclusive lock.The common methods of Reentrantreadwritelock are as follows:Readlock: Get read lock Object Reentrantreadwritelock.readlockWritelock: Get write Lock Object Reentrantreadwritelock.wri

synchronizationThe sync mode here is to look at these two articles, which provide a link to the next article.Qmutex, Qreadwritelock, Qsemaphore, qwaitcondition provide a means of thread synchronization. The main idea of using threads is to expect them to run as concurrently as possible, while some key points need to be stopped or waiting between them.For example, suppose two threads attempt to access the same global variable at the same time. The results may not be as good as you wish.Qmutex pr

address space of the parent process after the anonymous mapping. Also inherits the address returned by the mmap, so that the parent-child process can communicate through the mapping area. Note that the address returned by MMAP needs to be maintained by the parent process together. The first approach can be used for any of the two processes, and the best way to implement shared memory for a relational process should be to use an anonymous memory map. At this point, you do not have to specif

function Pthread_mutex_lock, when it finds that deadlock is unavoidable, it returns the appropriate information, and the programmer can handle the deadlock accordingly. In addition, different types of mutexes do not deal with deadlocks, but the main thing is for programmers to pay attention to this in their own programming.2.3 Item VariablesIn the previous section we talked about how to use mutexes to share and communicate data between threads, and one obvious disadvantage of mutexes is that it

Description of the flock () function Description Item Description Header file #include Function prototypes int flock (int fd, int operation) function description 2. This function can only handle files on a single host and cannot process files on NFS. 3. This function locks and unlocks the files that the FD lock points to, as specified by operation. 4. This function c

user and move the files in the original home directory to the new directory.-L: Modifies the user login name.-L: Lock the user.-U--unlock: Unlocks the user.CHSH: Role Modifies the user's default shell.CHFN: Role Modify user comment information.passwd Role Modify the user password. Options --stdin: Reads the password from the standard input.-L: Lock the user account.-U:

semaphore typically initializes the semaphore resource instance to 1 (the value of the semaphore is initialized to 1), which means that the system has a resource available by default. When a thread needs access to a critical resource, it needs to obtain the resource lock first. When this thread succeeds in obtaining a resource lock, other threads that intend to access the critical section will be suspended on that semaphore because the lock has been locked when other threads attempt to acquire

GNU organization, and the. Gz end file is the result of gzip compression. The decompression procedure relative to Gzip is gunzip. Use the-Z parameter in tar to invoke gzip. 　　　 # tar-czf all.tar.gz *.jpgThis command is to make all. jpg files into a tar package and compress them in gzip to generate a gzip compressed package named all.tar.gz# TAR-XZF all.tar.gzThis command unlocks the package generated above.Bzip2 is a more compressible compression pro

Pthread_exit, or the return value in the return statement. This function can be used for synchronization between threads. =============================================================intPthread_mutex_init (pthread_mutex_t*Mutex,Constpthread_mutex_attr_t*attr); //The function initializes a mutex variable, and if the parameter attr is null, the mutex//the body variable mutex uses the default property. =============================================================intPthread_mutex_lock (pthread_mu

file.Example 02Command: Gzip–r Testfile.tarInput:[Email protected] root]# gzip–r Testfile.tar[[email protected] root]# ls[Email protected] root]#DescriptionCompress a tar backup file with a. tar.gz file name extension.-R or--recursive recursively handles all files and subdirectories under the specified directory.010Linux jar Command1 command formatjar [Options] [Files] format jar [option] [file]2 command functionsJar command, unzip the zip, war file.3 Common examplesExample 01Command: JAR–XVF t

object's current Markword, another thread acquires the object lock before performing the CAS operation, and we start with the assumption that "the locked code does not occur concurrently" fails. At this point, the lightweight lock will not be directly inflated to a heavyweight lock, the thread will repeatedly retry the CAS operation sent to the lock of the holding thread to actively release the lock, after a certain number of spins if the lock has not been successfully acquired, then the lightw

can lock and unlock the resource before and after using the resource. Pretend to lock the copier, only one employee has the key at any one time. If you don't have a key, you can't use the copier. Locking a shared variable allows Java threads to communicate and synchronize quickly and easily. A line Chengjo a lock on an object to know that no other thread can access the object. Even in a preemptive model, no other thread can access the object until the locked thread wakes up, completes the work,

, otherwise the ebusy is returned . Because the condition variables of the Linux implementation do not allocate any resources, the logoff action only includes checking for a wait thread. 2. Waiting and stimulating 2.1 Waiting int pthread_cond_wait (pthread_cond_t *cond, pthread_mutex_t *mutex)This function is the core of the POSIX thread signaling system and the most incomprehensible part of the process: unlock-wait-receive signal-lock-return. 2.2 set time to wait int pthread_cond_time