In computer operating systems, a process (or task) may wait on another process to complete its execution. … The parent process may then issue a wait system call, which suspends the execution of the parent process while the child executes.
Ko gaida () dara?
Pagaidiet () funkcija apturēt izsaucošā pavediena izpildi, līdz ir pieejama statusa informācija vienam no tā pārtrauktajiem pakārtotajiem procesiem, vai līdz signāla piegādei, kura darbība ir vai nu signāla uztveršanas funkcijas izpilde vai procesa pārtraukšana.
How does wait work?
The wait() system call suspends execution of the current process until one of its children terminates. The call wait(&status) is equivalent to: waitpid(-1, &status, 0); The waitpid() system call suspends execution of the current process until a child specified by pid argument has changed state.
Kāda ir atšķirība starp gaidīšanu un gaidīšanu?
Jūsu darbs IR Klientu apkalpošana gaidīšanas funkcija var bloķēt zvanītāju, līdz tiek pārtraukts bērna process, savukārt waitpid ir opcija, kas neļauj tai bloķēt. Funkcija waitpid negaida bērnu, kurš beidz darbu pirmais; tai ir vairākas iespējas, kas kontrolē, kuru procesu tas gaida.
Ko nozīmē sistēmas izsaukums?
In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the kernel of the operating system on which it is executed. … System calls provide an essential interface between a process and the operating system.
What is Pid_t?
pid_t datu tips apzīmē procesa identifikāciju un to izmanto, lai attēlotu procesa ID. Ikreiz, kad mēs vēlamies deklarēt mainīgo, kas tiks galā ar procesa ID, mēs varam izmantot pid_t datu tipu. Pid_t datu tips ir vesela skaitļa veids (signed int vai mēs varam teikt int).
How does Waitpid work?
If pid is greater than 0, waitpid() waits for termination of the specific child whose process ID is equal to pid. If pid is equal to zero, waitpid() waits for termination of any child whose process group ID is equal to that of the caller.
Kas ir miegs () valodā C?
The function sleep gives a simple way to make the program wait for a short interval. … The sleep function waits for seconds seconds or until a signal is delivered, whichever happens first. If sleep returns because the requested interval is over, it returns a value of zero.
What is Wexitstatus?
This macro queries the child termination status provided by the wait and waitpid functions. If the WIFEXITED macro indicates that the child process exited normally, the WEXITSTATUS macro returns the exit code specified by the child process.
What does wait Null?
1 Answer. wait(NULL) will block parent process until any of its children has finished. If child terminates before parent process reaches wait(NULL) then the child process turns to a zombie process until its parent waits on it and its released from memory.
What happens when a process terminates but its parent does not wait for it?
Zombie process is that process which has terminated but whose process control block has not been cleaned up from main memory because the parent process was not waiting for the child.
Kas ir gaidīt () Java?
Vienkārši sakot, gaidiet () ir instances metode, kas tiek izmantota pavedienu sinhronizēšanai. To var izsaukt jebkurā objektā, jo tas ir definēts tieši Java. lang. Objekts, bet to var izsaukt tikai no sinhronizēta bloka. Tas atbrīvo objekta slēdzeni, lai cits pavediens varētu ielēkt un iegūt slēdzeni.