Fix poll to never return EINTR.

Bug: 18759467
Change-Id: Ia5b97a55318b5990ad6b80d15641223aa4fb06f5

5 files changed, 56 insertions, 44 deletions

diff --git a/luni/src/main/java/android/system/Os.java b/luni/src/main/java/android/system/Os.java
index 7f73a85..2626685 100644
--- a/luni/src/main/java/android/system/Os.java
+++ b/luni/src/main/java/android/system/Os.java
@@ -308,6 +308,10 @@ public final class Os {
 
   /**
    * See <a href="http://man7.org/linux/man-pages/man2/poll.2.html">poll(2)</a>.
+   *
+   * <p>Note that in Lollipop this could throw an {@code ErrnoException} with {@code EINTR}.
+   * In later releases, the implementation will automatically just restart the system call with
+   * an appropriately reduced timeout.
    */
   public static int poll(StructPollfd[] fds, int timeoutMs) throws ErrnoException { return Libcore.os.poll(fds, timeoutMs); }
 
diff --git a/luni/src/main/java/java/nio/SelectorImpl.java b/luni/src/main/java/java/nio/SelectorImpl.java
index 5e2a2b1..c73ba22 100644
--- a/luni/src/main/java/java/nio/SelectorImpl.java
+++ b/luni/src/main/java/java/nio/SelectorImpl.java
@@ -38,7 +38,6 @@ import libcore.io.IoBridge;
 import libcore.io.IoUtils;
 import libcore.io.Libcore;
 
-import static android.system.OsConstants.EINTR;
 import static android.system.OsConstants.POLLERR;
 import static android.system.OsConstants.POLLHUP;
 import static android.system.OsConstants.POLLIN;
@@ -183,9 +182,7 @@ final class SelectorImpl extends AbstractSelector {
                         try {
                             rc = Libcore.os.poll(pollFds.array(), (int) timeout);
                         } catch (ErrnoException errnoException) {
-                            if (errnoException.errno != EINTR) {
-                                throw errnoException.rethrowAsIOException();
-                            }
+                            throw errnoException.rethrowAsIOException();
                         }
                     } finally {
                         if (isBlocking) {
diff --git a/luni/src/main/java/libcore/io/IoBridge.java b/luni/src/main/java/libcore/io/IoBridge.java
index acc8d4f..fcb30dd 100644
--- a/luni/src/main/java/libcore/io/IoBridge.java
+++ b/luni/src/main/java/libcore/io/IoBridge.java
@@ -225,11 +225,7 @@ public final class IoBridge {
             if (!fd.valid()) {
                 throw new SocketException("Socket closed");
             }
-            if (errnoException.errno == EINTR) {
-                return false; // Punt and ask the caller to try again.
-            } else {
-                cause = errnoException;
-            }
+            cause = errnoException;
         }
         String detail = connectDetail(inetAddress, port, timeoutMs, cause);
         if (cause.errno == ETIMEDOUT) {
diff --git a/luni/src/main/native/libcore_io_Posix.cpp b/luni/src/main/native/libcore_io_Posix.cpp
index 57ff794..c585fc5 100644
--- a/luni/src/main/native/libcore_io_Posix.cpp
+++ b/luni/src/main/native/libcore_io_Posix.cpp
@@ -551,7 +551,7 @@ static void Posix_execve(JNIEnv* env, jobject, jstring javaFilename, jobjectArra
 
     ExecStrings argv(env, javaArgv);
     ExecStrings envp(env, javaEnvp);
-    execve(path.c_str(), argv.get(), envp.get());
+    TEMP_FAILURE_RETRY(execve(path.c_str(), argv.get(), envp.get()));
 
     throwErrnoException(env, "execve");
 }
@@ -563,7 +563,7 @@ static void Posix_execv(JNIEnv* env, jobject, jstring javaFilename, jobjectArray
     }
 
     ExecStrings argv(env, javaArgv);
-    execv(path.c_str(), argv.get());
+    TEMP_FAILURE_RETRY(execv(path.c_str(), argv.get()));
 
     throwErrnoException(env, "execv");
 }
@@ -724,15 +724,15 @@ static jobjectArray Posix_android_getaddrinfo(JNIEnv* env, jobject, jstring java
 }
 
 static jint Posix_getegid(JNIEnv*, jobject) {
-    return getegid();
+    return TEMP_FAILURE_RETRY(getegid());
 }
 
 static jint Posix_geteuid(JNIEnv*, jobject) {
-    return geteuid();
+    return TEMP_FAILURE_RETRY(geteuid());
 }
 
 static jint Posix_getgid(JNIEnv*, jobject) {
-    return getgid();
+    return TEMP_FAILURE_RETRY(getgid());
 }
 
 static jstring Posix_getenv(JNIEnv* env, jobject, jstring javaName) {
@@ -764,11 +764,11 @@ static jobject Posix_getpeername(JNIEnv* env, jobject, jobject javaFd) {
 }
 
 static jint Posix_getpid(JNIEnv*, jobject) {
-    return getpid();
+    return TEMP_FAILURE_RETRY(getpid());
 }
 
 static jint Posix_getppid(JNIEnv*, jobject) {
-    return getppid();
+    return TEMP_FAILURE_RETRY(getppid());
 }
 
 static jobject Posix_getpwnam(JNIEnv* env, jobject, jstring javaName) {
@@ -867,14 +867,14 @@ static jint Posix_gettid(JNIEnv* env __unused, jobject) {
   }
   return static_cast<jint>(owner);
 #elif defined(__BIONIC__)
-  return gettid();
+  return TEMP_FAILURE_RETRY(gettid());
 #else
   return syscall(__NR_gettid);
 #endif
 }
 
 static jint Posix_getuid(JNIEnv*, jobject) {
-    return getuid();
+    return TEMP_FAILURE_RETRY(getuid());
 }
 
 static jstring Posix_if_indextoname(JNIEnv* env, jobject, jint index) {
@@ -1088,7 +1088,40 @@ static jint Posix_poll(JNIEnv* env, jobject, jobjectArray javaStructs, jint time
     for (size_t i = 0; i < count; ++i) {
         monitors.push_back(new AsynchronousCloseMonitor(fds[i].fd));
     }
-    int rc = poll(fds.get(), count, timeoutMs);
+
+    int rc;
+    while (true) {
+        timespec before;
+        clock_gettime(CLOCK_MONOTONIC, &before);
+
+        rc = poll(fds.get(), count, timeoutMs);
+        if (rc >= 0 || errno != EINTR) {
+            break;
+        }
+
+        // We got EINTR. Work out how much of the original timeout is still left.
+        if (timeoutMs > 0) {
+            timespec now;
+            clock_gettime(CLOCK_MONOTONIC, &now);
+
+            timespec diff;
+            diff.tv_sec = now.tv_sec - before.tv_sec;
+            diff.tv_nsec = now.tv_nsec - before.tv_nsec;
+            if (diff.tv_nsec < 0) {
+                --diff.tv_sec;
+                diff.tv_nsec += 1000000000;
+            }
+
+            jint diffMs = diff.tv_sec * 1000 + diff.tv_nsec / 1000000;
+            if (diffMs >= timeoutMs) {
+                rc = 0; // We have less than 1ms left anyway, so just time out.
+                break;
+            }
+
+            timeoutMs -= diffMs;
+        }
+    }
+
     for (size_t i = 0; i < monitors.size(); ++i) {
         delete monitors[i];
     }
@@ -1115,7 +1148,8 @@ static void Posix_posix_fallocate(JNIEnv* env, jobject, jobject javaFd __unused,
                       "fallocate doesn't exist on a Mac");
 #else
     int fd = jniGetFDFromFileDescriptor(env, javaFd);
-    errno = TEMP_FAILURE_RETRY(posix_fallocate64(fd, offset, length));
+    while ((errno = posix_fallocate64(fd, offset, length)) == EINTR) {
+    }
     if (errno != 0) {
         throwErrnoException(env, "posix_fallocate");
     }
@@ -1128,9 +1162,11 @@ static jint Posix_prctl(JNIEnv* env, jobject, jint option __unused, jlong arg2 _
     jniThrowException(env, "java/lang/UnsupportedOperationException", "prctl doesn't exist on a Mac");
     return 0;
 #else
-    int result = prctl(static_cast<int>(option),
-                       static_cast<unsigned long>(arg2), static_cast<unsigned long>(arg3),
-                       static_cast<unsigned long>(arg4), static_cast<unsigned long>(arg5));
+    int result = TEMP_FAILURE_RETRY(prctl(static_cast<int>(option),
+                                          static_cast<unsigned long>(arg2),
+                                          static_cast<unsigned long>(arg3),
+                                          static_cast<unsigned long>(arg4),
+                                          static_cast<unsigned long>(arg5)));
     return throwIfMinusOne(env, "prctl", result);
 #endif
 }
diff --git a/luni/src/test/java/libcore/java/nio/channels/SelectorTest.java b/luni/src/test/java/libcore/java/nio/channels/SelectorTest.java
index 9789197..41b434d 100644
--- a/luni/src/test/java/libcore/java/nio/channels/SelectorTest.java
+++ b/luni/src/test/java/libcore/java/nio/channels/SelectorTest.java
@@ -15,7 +15,6 @@
  */
 package libcore.java.nio.channels;
 
-import android.system.OsConstants;
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
@@ -28,7 +27,6 @@ import java.nio.channels.SocketChannel;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 import junit.framework.TestCase;
-import libcore.io.Libcore;
 import tests.net.StuckServer;
 
 public class SelectorTest extends TestCase {
@@ -71,25 +69,6 @@ public class SelectorTest extends TestCase {
         }
     }
 
-    // http://b/6453247
-    // This test won't work on the host until/unless we start using libcorkscrew there.
-    // The runtime itself blocks SIGQUIT, so that doesn't cause poll(2) to EINTR directly.
-    // The EINTR is caused by the way libcorkscrew works.
-    public void testEINTR() throws Exception {
-        Selector selector = Selector.open();
-        new Thread(new Runnable() {
-            @Override public void run() {
-                try {
-                    Thread.sleep(2000);
-                    Libcore.os.kill(Libcore.os.getpid(), OsConstants.SIGQUIT);
-                } catch (Exception ex) {
-                    fail();
-                }
-            }
-        }).start();
-        assertEquals(0, selector.select());
-    }
-
     // http://code.google.com/p/android/issues/detail?id=15388
     public void testInterrupted() throws IOException {
         Selector selector = Selector.open();