forked from OSchip/llvm-project
60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
/* This is a test case where the parent process forks 10
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* children which contend to write to the same file. With
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* file locking support, the data from each child should not
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* be lost.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/wait.h>
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extern FILE *lprofOpenFileEx(const char *);
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int main(int argc, char *argv[]) {
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pid_t tid;
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FILE *F;
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const char *FN;
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int child[10];
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int c;
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int i;
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if (argc < 2) {
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fprintf(stderr, "Requires one argument \n");
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exit(1);
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}
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FN = argv[1];
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truncate(FN, 0);
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for (i = 0; i < 10; i++) {
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c = fork();
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// in child:
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if (c == 0) {
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FILE *F = lprofOpenFileEx(FN);
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if (!F) {
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fprintf(stderr, "Can not open file %s from child\n", FN);
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exit(1);
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}
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fseek(F, 0, SEEK_END);
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fprintf(F, "Dump from Child %d\n", i);
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fclose(F);
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exit(0);
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} else {
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child[i] = c;
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}
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}
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// In parent
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for (i = 0; i < 10; i++) {
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int child_status;
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if ((tid = waitpid(child[i], &child_status, 0)) == -1)
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break;
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}
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F = lprofOpenFileEx(FN);
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if (!F) {
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fprintf(stderr, "Can not open file %s from parent\n", FN);
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exit(1);
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}
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fseek(F, 0, SEEK_END);
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fprintf(F, "Dump from parent %d\n", i);
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return 0;
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}
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