Add epoll test

src/header/sys_epoll/cbindgen.toml

@@ -1,4 +1,4 @@
-sys_includes = []
+sys_includes = ["signal.h"]
 include_guard = "_SYS_EPOLL_H"
 language = "C"
 style = "Tag"

tests/Makefile

@@ -61,6 +61,7 @@ EXPECT_BINS=\
 	string/strtok \
 	string/strtok_r \
 	strings \
+	sys_epoll/epoll \
 	time/asctime \
 	time/gmtime \
 	time/localtime \

tests/sys_epoll/epoll.c

@@ -0,0 +1,158 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/epoll.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+int reader(int fd) {
+    // Create an epoll file
+    int epollfd = epoll_create1(EPOLL_CLOEXEC);
+    if (epollfd < 0) {
+        perror("epoll_create1");
+        return 1;
+    }
+
+    // Register for events from the reader file
+    struct epoll_event ev;
+    ev.events = EPOLLIN;
+    ev.data.fd = fd;
+    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) < 0) {
+        perror("epoll_ctl");
+        return 1;
+    }
+
+    // Process exactly 1024 events
+    struct epoll_event events[8];
+    for (int i = 0; i < 1024; i++) {
+        // Wait for the next event
+        int nfds = epoll_wait(epollfd, events, sizeof(events)/sizeof(struct epoll_event), -1);
+        if (nfds < 0) {
+            perror("epoll_wait");
+            return 1;
+        }
+
+        // For each event received
+        for (int n = 0; n < nfds; n++) {
+            // If the event is the reader file
+            if (events[n].data.fd == fd) {
+                // Read the current event count
+                int writer_i;
+                int count = read(fd, &writer_i, sizeof(writer_i));
+                if (count < 0) {
+                    perror("read");
+                    return 1;
+                } else if (count < sizeof(writer_i)) {
+                    fprintf(stderr, "read %d instead of %d\n", count, sizeof(writer_i));
+                    return 1;
+                }
+                // Make sure the writer's event count matches our own
+                if (i != writer_i) {
+                    fprintf(stderr, "received event count %d instead of %d\n", writer_i, i);
+                    return 1;
+                }
+                printf("%d == %d\n", i, writer_i);
+            } else {
+                // Otherwise, return an error
+                fprintf(stderr, "unknown fd %d\n", events[n].data.fd);
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int writer(int fd) {
+    // Create an epoll file
+    int epollfd = epoll_create1(EPOLL_CLOEXEC);
+    if (epollfd < 0) {
+        perror("epoll_create1");
+        return 1;
+    }
+
+    // Register for events from the writer file
+    struct epoll_event ev;
+    ev.events = EPOLLOUT;
+    ev.data.fd = fd;
+    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) < 0) {
+        perror("epoll_ctl");
+        return 1;
+    }
+
+    // Process exactly 1024 events
+    struct epoll_event events[8];
+    for (int i = 0; i < 1024; i++) {
+        // Wait for the next event
+        int nfds = epoll_wait(epollfd, events, sizeof(events)/sizeof(struct epoll_event), -1);
+        if (nfds < 0) {
+            perror("epoll_wait");
+            return 1;
+        }
+
+        // For each event received
+        for (int n = 0; n < nfds; n++) {
+            // If the event is the writer file
+            if (events[n].data.fd == fd) {
+                // Write the current event count
+                int count = write(fd, &i, sizeof(i));
+                if (count < 0) {
+                    perror("write");
+                    return 1;
+                } else if (count < sizeof(i)) {
+                    fprintf(stderr, "wrote %d instead of %d\n", count, sizeof(i));
+                    return 1;
+                }
+            } else {
+                // Otherwise, return an error
+                fprintf(stderr, "unknown fd %d\n", events[n].data.fd);
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int main(int argc, char **argv) {
+    // Create a non-blocking pipe to use for epoll testing
+    int pipefd[2];
+    if (pipe2(pipefd, O_CLOEXEC | O_NONBLOCK) < 0) {
+        perror("pipe2");
+        return 1;
+    }
+
+    pid_t pid = fork();
+    if (pid < 0) {
+        perror("fork");
+        return 1;
+    } else if (pid == 0) {
+        // Child process will read events
+        close(pipefd[1]);
+        return reader(pipefd[0]);
+    } else {
+        // Parent process will write events
+        close(pipefd[0]);
+        int ret = writer(pipefd[1]);
+
+        // Wait for child process
+        int status = 0;
+        if (waitpid(pid, &status, 0) != pid) {
+            perror("waitpid");
+            return 1;
+        }
+
+        // If writer failed, return exit status
+        if (ret != 0) {
+            return ret;
+        }
+
+        // If child exited with exit status
+        if (WIFEXITED(status)) {
+            // Return the child's exit status
+            return WEXITSTATUS(status);
+        } else {
+            // Otherwise, return 1
+            return 1;
+        }
+    }
+}