Add fcntlInt to public API

In order to allow sockets to be set as non-blocking after the creation,
fcntlInt must be exposed.

Test: new tests added, passing
Change-Id: If30d3750734a5a3910587a06df334c04fad92703

3 files changed, 43 insertions, 4 deletions

diff --git a/luni/src/main/java/android/system/Os.java b/luni/src/main/java/android/system/Os.java
index e2b191eee7..70fdce5c16 100644
--- a/luni/src/main/java/android/system/Os.java
+++ b/luni/src/main/java/android/system/Os.java
@@ -151,9 +151,10 @@ public final class Os {
      */
     public static void fchown(FileDescriptor fd, int uid, int gid) throws ErrnoException { Libcore.os.fchown(fd, uid, gid); }
 
-    /** @hide */
-    @libcore.api.CorePlatformApi
-    public static int fcntlInt(FileDescriptor fd, int cmd, int arg) throws ErrnoException { return Libcore.os.fcntlInt(fd, cmd, arg); }
+    /**
+     * See <a href="http://man7.org/linux/man-pages/man2/fcntl.2.html">fcntl(2)</a>.
+     */
+    public static int fcntlInt(@NonNull FileDescriptor fd, int cmd, int arg) throws ErrnoException { return Libcore.os.fcntlInt(fd, cmd, arg); }
 
     /** @hide */
     public static int fcntlVoid(FileDescriptor fd, int cmd) throws ErrnoException { return Libcore.os.fcntlVoid(fd, cmd); }
diff --git a/luni/src/test/java/libcore/android/system/OsTest.java b/luni/src/test/java/libcore/android/system/OsTest.java
index 25d56bcbc3..0c650462cc 100644
--- a/luni/src/test/java/libcore/android/system/OsTest.java
+++ b/luni/src/test/java/libcore/android/system/OsTest.java
@@ -87,6 +87,45 @@ public class OsTest extends TestCase {
         }
     }
 
+    public void testFcntlInt_UdpSocket() throws Exception {
+        final FileDescriptor fd = Os.socket(AF_INET, SOCK_DGRAM, 0);
+        try {
+            assertEquals(0, (Os.fcntlVoid(fd, F_GETFL) & O_NONBLOCK));
+
+            // Verify that we can set file descriptor flags on sockets
+            Os.fcntlInt(fd, F_SETFL, SOCK_DGRAM | O_NONBLOCK);
+            assertTrue((Os.fcntlVoid(fd, F_GETFL) & O_NONBLOCK) != 0);
+
+            // Check that we can turn it off also.
+            Os.fcntlInt(fd, F_SETFL, SOCK_DGRAM);
+            assertEquals(0, (Os.fcntlVoid(fd, F_GETFL) & O_NONBLOCK));
+        } finally {
+            Os.close(fd);
+        }
+    }
+
+    public void testFcntlInt_InvalidCmd() throws Exception {
+        final FileDescriptor fd = Os.socket(AF_INET, SOCK_DGRAM, 0);
+        try {
+            final int unknownCmd = -1;
+            Os.fcntlInt(fd, unknownCmd, 0);
+            fail("Expected failure due to invalid cmd");
+        } catch (ErrnoException expected) {
+            assertEquals(EINVAL, expected.errno);
+        } finally {
+            Os.close(fd);
+        }
+    }
+
+    public void testFcntlInt_NullFd() throws Exception {
+        try {
+            Os.fcntlInt(null, F_SETFL, O_NONBLOCK);
+            fail("Expected failure due to null file descriptor");
+        } catch (ErrnoException expected) {
+            assertEquals(EBADF, expected.errno);
+        }
+    }
+
     public void testUnixDomainSockets_in_file_system() throws Exception {
         String path = System.getProperty("java.io.tmpdir") + "/test_unix_socket";
         new File(path).delete();
diff --git a/mmodules/core_platform_api/api/platform/current-api.txt b/mmodules/core_platform_api/api/platform/current-api.txt
index 8abb9be236..28231569cb 100644
--- a/mmodules/core_platform_api/api/platform/current-api.txt
+++ b/mmodules/core_platform_api/api/platform/current-api.txt
@@ -44,7 +44,6 @@ package android.system {
   public final class Os {
     method public static android.system.StructCapUserData[] capget(android.system.StructCapUserHeader) throws android.system.ErrnoException;
     method public static void capset(android.system.StructCapUserHeader, android.system.StructCapUserData[]) throws android.system.ErrnoException;
-    method public static int fcntlInt(java.io.FileDescriptor, int, int) throws android.system.ErrnoException;
     method public static int getpgid(int) throws android.system.ErrnoException;
     method public static android.system.StructRlimit getrlimit(int) throws android.system.ErrnoException;
     method public static int getsockoptInt(java.io.FileDescriptor, int, int) throws android.system.ErrnoException;