Add a regression test for the big pipe bug.

Suggested by: silby

1 files changed, 78 insertions, 0 deletions

diff --git a/tools/regression/pipe/bigpipetest.c b/tools/regression/pipe/bigpipetest.c
new file mode 100644
index 0000000..1eb3776
--- /dev/null
+++ b/tools/regression/pipe/bigpipetest.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/select.h>
+#include <sys/pipe.h>
+#include <string.h>
+#include <errno.h>
+
+/*
+ * Test for the non-blocking big pipe bug (write(2) returning
+ * EAGAIN while select(2) returns the descriptor as ready for write).
+ *
+ * $FreeBSD$
+ */
+
+void write_frame(int fd, char *buf, unsigned long buflen)
+{
+    fd_set wfd;
+    int i;
+
+    while (buflen) {
+	FD_ZERO(&wfd);
+	FD_SET(fd, &wfd);
+	i = select(fd+1, NULL, &wfd, NULL, NULL);
+	if (i < 0) {
+	    perror("select");
+	    exit(1);
+	}
+	if (i != 1) {
+	    fprintf(stderr, "select returned unexpected value %d\n", i);
+	    exit(1);
+	}
+        i = write(fd, buf, buflen);
+	if (i < 0) {
+	    if (errno != EAGAIN)
+		perror("write");
+	    exit(1);
+	}
+        buf += i;
+        buflen -= i;
+    }
+}
+
+int main()
+{
+    char buf[BIG_PIPE_SIZE];	/* any value over PIPE_SIZE should do */
+    int i, flags, fd[2];
+
+    if (pipe(fd) < 0) { perror("pipe"); exit(1); }
+
+    flags = fcntl(fd[1], F_GETFL);
+    if (flags == -1 || fcntl(fd[1], F_SETFL, flags|O_NONBLOCK) == -1) {
+	perror("fcntl");
+	exit(1);
+    }
+
+    switch (fork()) {
+	case -1:
+	    perror("fork");
+	    exit(1);
+	case 0:
+	    close(fd[1]);
+	    for (;;) {
+		i = read(fd[0], buf, 256); /* any small size should do */
+		if (i == 0) break;
+		if (i < 0) { perror("read"); exit(1); }
+	    }
+	    exit(0);
+	default:
+	    break;
+    }
+
+    close(fd[0]);
+    memset(buf, 0, sizeof buf);
+    for (i = 0; i < 1000; i++) write_frame(fd[1], buf, sizeof buf);
+    exit(0);
+}