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#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define IMAX 256
#define JMAX 16
#define KMAX 16
#define ISTEP (JMAX * KMAX)
#define WAIT \
do \
{ \
while (waitpid(-1, &status, 0) > 0) \
{ \
if (status == 0) \
{ \
passed++; \
} \
else \
{ \
failed++; \
} \
} \
} while (0)
int main(int argc, char **argv)
{
int passed = 0;
int failed = 0;
int status;
int pipefd[2];
/* First test: normal operation.
* The writer writes a specific sequence of 64K
* bytes into the pipe, and the reader expects
* the same bytes out.
*/
printf("Testing normal operation...\n");
int ret = pipe(pipefd);
if (ret < 0)
{
fprintf(stderr, "pipe: %s\n", strerror(errno));
exit(1);
}
int i, j, k;
unsigned char buf[KMAX];
if (!fork())
{
close(pipefd[0]);
for (i = 0; i < IMAX; ++i)
{
for (j = 0; j < JMAX; ++j)
{
for (k = 0; k < KMAX; ++k)
{
buf[k] = i ^ (j * KMAX + k);
}
if (write(pipefd[1], buf, KMAX) < 0)
{
printf("Write to pipe failed\n");
exit(1);
}
}
}
exit(0);
}
if (!fork())
{
close(pipefd[1]);
for (i = 0; i < IMAX; ++i)
{
for (j = 0; j < JMAX; ++j)
{
if (read(pipefd[0], buf, KMAX) == 0)
{
printf("Unexpected end of pipe\n");
exit(1);
}
for (k = 0; k < KMAX; ++k)
{
if (buf[k] != (i ^ (j * KMAX + k)))
{
printf("Byte %d incorrect (expected %2x, got %2x)\n",
i * ISTEP + j * KMAX + k, (i ^ (j * KMAX + k)),
buf[k]);
exit(1);
}
}
}
}
exit(0);
}
close(pipefd[0]);
close(pipefd[1]);
WAIT;
/* Second test: broken pipe.
* All readers quit immediately. The writer should get EPIPE.
*/
printf("Testing with no readers...\n");
ret = pipe(pipefd);
if (ret < 0)
{
fprintf(stderr, "pipe: %s\n", strerror(errno));
exit(1);
}
if (!fork())
{
close(pipefd[0]);
for (i = 0; i < IMAX; ++i)
{
for (j = 0; j < JMAX; ++j)
{
for (k = 0; k < KMAX; ++k)
{
buf[k] = i ^ (j * KMAX + k);
}
if (write(pipefd[1], buf, KMAX) < 0)
{
if (errno == EPIPE)
{
exit(0);
}
else
{
printf("Write to pipe failed\n");
exit(1);
}
}
}
}
exit(1);
}
close(pipefd[0]);
close(pipefd[1]);
WAIT;
/* Third test: writers quit.
* The readers should get no bytes, and this program
* should not block in the kernel forever.
*/
printf("Testing with no writers...\n");
ret = pipe(pipefd);
if (ret < 0)
{
fprintf(stderr, "pipe: %s\n", strerror(errno));
exit(1);
}
if (!fork())
{
close(pipefd[1]);
if (read(pipefd[0], buf, KMAX) == 0)
{
exit(0);
}
exit(1);
}
if (!fork())
{
close(pipefd[1]);
if (read(pipefd[0], buf, KMAX) == 0)
{
exit(0);
}
exit(1);
}
close(pipefd[0]);
close(pipefd[1]);
WAIT;
printf("%d passed. %d failed.\n", passed, failed);
return 0;
}
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