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@@ -0,0 +1,210 @@
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+#include <errno.h>
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+#include <fcntl.h>
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+#include <signal.h>
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+#include <stdio.h>
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+#include <stdlib.h>
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+#include <string.h>
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+#include <sys/stat.h>
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+#include <sys/wait.h>
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+#include <unistd.h>
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+
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+#define TEST_ASSERT(left, right, success_msg, fail_msg) \
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+ do { \
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+ if ((left) == (right)) { \
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+ printf("[PASS] %s\n", success_msg); \
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+ } else { \
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+ printf("[FAIL] %s: Expected %d, but got %d\n", fail_msg, (right), \
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+ (left)); \
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+ } \
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+ } while (0)
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+
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+#define FIFO_PATH "/bin/test_fifo" // 使用 /tmp 目录避免权限问题
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+
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+typedef struct {
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+ int fd;
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+ int error_code;
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+} FifoWriteResult;
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+
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+// 信号处理函数
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+void sigpipe_handler(int signo) {
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+ if (signo == SIGPIPE) {
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+ printf("Received SIGPIPE signal. Write operation failed.\n");
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+ }
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+}
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+
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+const char *scenarios[] = {"No readers (FIFO never had readers)",
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+ "Reader exists but disconnects",
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+ "Active reader exists"};
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+
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+FifoWriteResult test_fifo_write(int scenario_index, int nonblocking) {
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+ FifoWriteResult result = {.fd = -1, .error_code = 0};
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+ int fd;
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+ const char *data = "Hello, FIFO!";
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+
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+ // Set write mode and non-blocking flag
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+ int flags = O_WRONLY;
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+ if (nonblocking) {
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+ flags |= O_NONBLOCK;
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+ }
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+
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+ // Open the FIFO write end
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+ fd = open(FIFO_PATH, flags);
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+ if (fd == -1) {
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+ result.fd = fd;
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+ result.error_code = errno;
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+
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+ if (errno == ENXIO) {
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+ printf("Result: Failed to open FIFO for writing (ENXIO: No readers).\n");
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+ } else {
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+ perror("Failed to open FIFO for writing");
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+ }
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+ return result; // Return early with error details
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+ }
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+
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+ // Write data
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+ ssize_t bytes_written = write(fd, data, strlen(data));
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+ if (bytes_written == -1) {
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+ result.error_code = errno;
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+
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+ if (bytes_written == -1) {
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+ if (errno == EPIPE) {
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+ printf("Result: Write failed with EPIPE (no readers available).\n");
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+ } else if (errno == ENXIO) {
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+ printf("Result: Write failed with ENXIO (FIFO never had readers).\n");
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+ } else if (errno == EAGAIN) {
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+ printf("Result: Write failed with EAGAIN (nonblocking write, pipe full "
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+ "or no readers).\n");
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+ } else {
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+ perror("Write failed with an unexpected error");
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+ }
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+ } else {
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+ printf("Result: Write succeeded. Bytes written: %zd\n", bytes_written);
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+ }
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+
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+ result.fd = fd;
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+ close(fd);
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+ return result; // Return with fd and error_code
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+ }
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+}
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+
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+void test_case1(int nonblocking) {
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+ // Case 1: No readers (FIFO never had readers)
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+ FifoWriteResult result = test_fifo_write(0, nonblocking);
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+
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+ char buffer[100];
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+ sprintf(buffer, "Fail with unexpected error %d", result.error_code);
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+ TEST_ASSERT(result.error_code, ENXIO, "write(2) fails with the error ENXIO",
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+ buffer);
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+}
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+
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+void test_case2(int nonblocking) {
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+ pid_t reader_pid;
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+
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+ // Case 2: Reader exists but disconnects
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+ reader_pid = fork();
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+ if (reader_pid == 0) {
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+ // Child process acts as a reader
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+ int reader_fd = open(FIFO_PATH, O_RDONLY);
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+ if (reader_fd == -1) {
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+ perror("Reader failed to open FIFO");
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+ exit(EXIT_FAILURE);
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+ }
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+ sleep(2); // Simulate a brief existence of the reader
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+ close(reader_fd);
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+ exit(EXIT_SUCCESS);
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+ }
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+
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+ sleep(5); // Ensure the reader has opened the FIFO
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+ FifoWriteResult result = test_fifo_write(1, nonblocking);
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+ waitpid(reader_pid, NULL, 0); // Wait for the reader process to exit
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+
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+ if (nonblocking) {
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+ TEST_ASSERT(result.error_code, EPIPE,
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+ "Non-Blocking Write failed with EPIPE",
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+ "Non-Blocking Write failed with wrong error type");
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+ } else {
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+ TEST_ASSERT(result.error_code, EPIPE, "Blocking Write failed with EPIPE",
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+ "Blocking Write failed with wrong error type");
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+ }
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+}
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+
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+void test_case3(int nonblocking) {
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+ pid_t reader_pid;
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+
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+ // Case 3: Active reader exists
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+ reader_pid = fork();
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+ if (reader_pid == 0) {
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+ // Child process acts as a reader
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+ int reader_fd = open(FIFO_PATH, O_RDONLY);
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+ if (reader_fd == -1) {
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+ perror("Reader failed to open FIFO");
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+ exit(EXIT_FAILURE);
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+ }
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+ sleep(5); // Keep the reader active
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+ close(reader_fd);
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+ exit(EXIT_SUCCESS);
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+ }
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+
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+ sleep(1); // Ensure the reader has opened the FIFO
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+ FifoWriteResult result = test_fifo_write(2, nonblocking);
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+
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+ waitpid(reader_pid, NULL, 0); // Wait for the reader process to exit
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+
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+ TEST_ASSERT(result.error_code, 0, "write succeed", "write failed");
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+}
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+
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+void run_tests(int nonblocking) {
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+ for (int i = 0; i < 3; i++) {
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+ printf("\n--- Testing: %s (nonblocking=%d) ---\n", scenarios[i],
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+ nonblocking);
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+ switch (i) {
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+ case 0:
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+ // test_case1(nonblocking);
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+ break;
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+ case 1:
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+ test_case2(nonblocking);
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+ break;
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+ case 2:
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+ // test_case3(nonblocking);
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+ break;
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+ }
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+ }
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+}
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+
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+void test_blocking() {
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+ // 创建 FIFO
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+ if (mkfifo(FIFO_PATH, 0666) == -1 && errno != EEXIST) {
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+ perror("mkfifo failed");
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+ exit(EXIT_FAILURE);
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+ }
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+
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+ // 测试阻塞模式下的三种情况
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+ printf("========== Testing Blocking Mode ==========\n");
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+ run_tests(0); // 阻塞模式
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+ // 删除 FIFO
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+ unlink(FIFO_PATH);
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+}
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+
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+void test_non_blocking() {
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+ // 创建 FIFO
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+ if (mkfifo(FIFO_PATH, 0666) == -1 && errno != EEXIST) {
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+ perror("mkfifo failed");
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+ exit(EXIT_FAILURE);
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+ }
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+ // 测试非阻塞模式下的三种情况
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+ printf("\n========== Testing Nonblocking Mode ==========\n");
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+ run_tests(1); // 非阻塞模式
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+ // 删除 FIFO
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+ unlink(FIFO_PATH);
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+}
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+
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+int main() {
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+ // 设置 SIGPIPE 信号处理
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+ signal(SIGPIPE, sigpipe_handler);
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+
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+// test_blocking();
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+ test_non_blocking();
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+
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+ printf("\nAll tests completed.\n");
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+ return 0;
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+}
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