74 lines
1.5 KiB
C++
74 lines
1.5 KiB
C++
/*
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* \brief Simple fork test
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* \author Norman Feske
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* \date 2012-02-14
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*/
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#include <stdio.h>
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#include <unistd.h>
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#include <errno.h>
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#include <sys/wait.h>
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enum { MAX_COUNT = 1000 };
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int main(int, char **)
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{
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printf("--- test-noux_fork started ---\n");
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pid_t fork_ret = fork();
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if (fork_ret < 0) {
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printf("Error: fork returned %d, errno=%d\n", fork_ret, errno);
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return -1;
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}
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printf("pid %d: fork returned %d\n", getpid(), fork_ret);
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/* child */
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if (fork_ret == 0) {
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printf("pid %d: child says hello\n", getpid());
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pid_t fork_ret = fork();
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if (fork_ret < 0) {
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printf("Error: fork returned %d, errno=%d\n", fork_ret, errno);
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return -1;
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}
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printf("pid %d: fork returned %d\n", getpid(), fork_ret);
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/* grand child */
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if (fork_ret == 0) {
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printf("pid %d: grand child says hello\n", getpid());
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for (int k = 0; k < MAX_COUNT; k++) {
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printf("pid %d: grand child k = %d\n", getpid(), k);
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}
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return 0;
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};
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for (int j = 0; j < MAX_COUNT; j++) {
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printf("pid %d: child j = %d\n", getpid(), j);
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}
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if (fork_ret != 0) {
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printf("pid %d: child waits for grand-child exit\n", getpid());
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waitpid(fork_ret, nullptr, 0);
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}
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return 0;
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}
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printf("pid %d: parent received child pid %d, starts counting...\n",
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getpid(), fork_ret);
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for (int i = 0; i < MAX_COUNT; ) {
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printf("pid %d: parent i = %d\n", getpid(), i++);
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}
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printf("pid %d: parent waits for child exit\n", getpid());
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waitpid(fork_ret, nullptr, 0);
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printf("--- parent done ---\n");
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return 0;
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}
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