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Excahnged clock() with gettimeofday()

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This commit is contained in:
Sergiusz Warga 2021-03-10 22:08:21 +01:00
parent b4a3c3aeae
commit 79fc63135b
2 changed files with 20 additions and 11 deletions
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3
.gitignore vendored
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@ -3,3 +3,6 @@ cmake-build-debug
CMakeLists.txt
.idea
*.o
# Apple
.DS_Store

28
Topic-2/task_2_4.c
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@ -4,11 +4,20 @@
#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <time.h>
const char * time_from_main_exec() {
struct timeval now;
gettimeofday(&now, NULL);
char buff[127];
sprintf(&buff, "us : %d", now.tv_usec);
return buff;
}
void parent_before_child() {
pid_t pid;
printf("\nparent_before_child()\n");
@ -18,11 +27,11 @@ void parent_before_child() {
exit(EXIT_FAILURE);
}
if (pid != 0) { // If this is a parent process.
printf("===\nI am a parent.\nMy PID is: %d\n===", getpid());
printf("===\n%s\nI am a parent.\nMy PID is: %d\n===", time_from_main_exec(), getpid());
kill(getpid(), SIGTERM);
} else {
sleep(1);
printf("===\nI am a child.\nMy PID is: %d\n===", getpid()); // This line will not be printed, as (usually) parent process will finish
printf("===\n%s\nI am a child.\nMy PID is: %d\n===", time_from_main_exec(), getpid()); // This line will not be printed, as (usually) parent process will finish
// its execution in less than 1 second
}
}
@ -37,31 +46,28 @@ void child_before_parent() {
exit(EXIT_FAILURE);
}
if (pid == 0) { // If this is a parent process.
printf("===\nI am a child.\nMy PID is: %d\n===", getpid());
printf("===\n%s\nI am a child.\nMy PID is: %d\n===", time_from_main_exec(), getpid());
kill(getpid(), SIGTERM);
} else {
sleep(1);
printf("===\nI am a parent.\nMy PID is: %d\n===", getpid());
printf("===\n%s\nI am a parent.\nMy PID is: %d\n===", time_from_main_exec(), getpid());
}
}
double time_from_exec(clock_t begin) {
return (double)(clock() - begin)/CLOCKS_PER_SEC;
}
int main() {
clock_t begin = clock();
pid_t pid;
printf("%f: Grandparent process has PID: %d\n", time_from_exec(begin), getpid());
printf("%s: Grandparent process has PID: %d\n", time_from_main_exec(), getpid());
pid = fork();
if (pid == 0) { // If child process
printf("%f: Process with PID %d will execute funs.\n", time_from_exec(begin), getpid());
printf("%s: Process with PID %d will execute funs.\n", time_from_main_exec(), getpid());
child_before_parent();
sleep(1);
parent_before_child();
sleep(1);
} else { // If parent process
printf("%f: Grandparent's child process has PID: %d\n", time_from_exec(begin), pid);
printf("%s: Grandparent's child process has PID: %d\n", time_from_main_exec(), pid);
sleep(5);
}
return 0;