operating system concepts essentials

Build MongoDB Service Based on CentOS 6.5 Operating System MongoDB is a non-relational database (NoSQL) that is very popular in the IT industry. Its flexible data storage method is favored by current IT practitioners. MongoDB implements the object-oriented idea (OO idea), and every record in MongoDB is a Document object. The biggest advantage of MongoDB is that all data persistence operations can easily imp

) {printf ("%8s%8d%8d%10d%10d%10c\n", pcb[i].name,pcb[i].priority,pcb[i].arrtime,pcb[i].needtime,pcb[i].usedtime,pcb[i].state); }}voidAttemper () { Do{ if((pcb[0].needtime-pcb[0].usedtime) >ptime)//determines whether the remaining elapsed time of the process is greater than the time slice{pcb[0].usedtime+=Ptime; pcb[0].priority--; pcb[0].state='W'; } Else //completed Processes{pcb[0].usedtime=pcb[0].needtime; pcb[0].priority=-1; pcb[0].state='F'; } Print ()

("\ n Process name \ t priority \ t arrives time \ t takes time \ t used time \ t process state \ n"); for(intI=0; i) {printf ("%s\t%d\t%d\t\t%d\t\t%d\t\t%c\n", Pcb[i].name,pcb[i].priority,pcb[i]. Arrtime,pcb[i]. Needtime,pcb[i]. Usedtime,pcb[i].state); } }voidMain () {intN; printf ("number of input processes:"); scanf ("%d",N); Input (n); intPtime; printf ("\n\t Input time slice:"); scanf ("%d",ptime); Panduan (n); Output (n); while(pcb[1].state!='F') {sort (n,ptime);p Anduan (n

].usetime++; }}voidArrivesort (structPCB pcbs[Ten],intN) { intI=0; Chartemp[Ten]; intmin; for(i=0; i1; i++) { if(pcbs[i].arrivetime>pcbs[i+1].arrivetime) {min=Pcbs[i].arrivetime; Pcbs[i].arrivetime=pcbs[i+1].arrivetime; Pcbs[i+1].arrivetime=min; Min=Pcbs[i].needtime; Pcbs[i].needtime=pcbs[i+1].needtime; Pcbs[i+1].needtime=min; Min=pcbs[i].priority; Pcbs[i].priority=pcbs[i+1].priority; Pcbs[i+1].priority=min; strcpy (Temp,pcbs[i].name); strcpy (Pcbs[i].name,pcbs[i+1]

Summary of this chapterThis chapter describes the basic concepts of users and users. Explains the creation, deletion, and modification of the properties of users and Groups in Windows Server2008. In the Linux section, the relevant properties of Linux, users and groups are introduced through the graphical Configuration tool, then the configuration files related to users and groups are explained, and finally, the use of commands to complete the manageme

running application, or a container, that, after the application is run, is the equivalent of loading the application into a container (you can also load variable data, referenced DLL files, and so on). A thread is the basic unit in which the operating system allocates processor time to a process. Any code that the thread can execute the process, including the part currently executed by the other. such as

strut hlist_head typePOS: A pointer to traverse, except that its data type is strut hlist_head typeMember: The variable name of the Hlist_head member in the data item type definition3> function Implementation:#define HLIST_FOR_EACH_ENTRY_CONTINUE (TPOs, POS, member)for (pos = (POS)->next;POS ({TPOs = Hlist_entry (pos,typeof (*tpos), member); 1;});pos = pos->next)3. Start traversing from the current node of the POS node in the hash list1>function: The traversal begins at a node at the current po

message that must be given when the message is written to the message queue, or read the first message in the queue if the read queue uses a message type of 0.The structure of the kernel space Msg_queue describes the case of the message queue corresponding to the key value, and corresponds to the msqid_ds of the user space, so the structure of the msgid_ds can be manipulated to operate the message queue. "Shared Memory" Shared memory is the fastest way to communicate between proc

and enters the next level queue if it is not completed.When the process is first ready, it enters the first-level queue.(3). (*) Consider the blocking State B (Blocked) of the process to increase the blocking queue. The time at which the process is blocked and blocked is determined by the resulting "random number" (the frequency and length of the blocking is more reasonable). Note that a process can be converted to a blocking state only if it is in a running state, and the process is only ready

) {printf ("%8s%8d%8d%10d%10d%10c\n", pcb[i].name,pcb[i].priority,pcb[i].arrtime,pcb[i].needtime,pcb[i].usedtime,pcb[i].state); }}voidAttemper () { Do{ if((pcb[0].needtime-pcb[0].usedtime) >ptime)//determines whether the remaining elapsed time of the process is greater than the time slice{pcb[0].usedtime+=Ptime; pcb[0].priority--; pcb[0].state='W'; } Else //completed Processes{pcb[0].usedtime=pcb[0].needtime; pcb[0].priority=-1; pcb[0].state='F'; } Print ()