merge heads

Lib/test/test_io.py

@@ -2912,7 +2912,7 @@ class SignalsTest(unittest.TestCase):
         try:
             wio = self.io.open(w, **fdopen_kwargs)
             t.start()
-            signal.alarm(1)
+            signal.setitimer(signal.ITIMER_REAL, 0.1)
             # Fill the pipe enough that the write will be blocking.
             # It will be interrupted by the timer armed above.  Since the
             # other thread has read one byte, the low-level write will
@@ -2957,7 +2957,7 @@ class SignalsTest(unittest.TestCase):
         r, w = os.pipe()
         wio = self.io.open(w, **fdopen_kwargs)
         try:
-            signal.alarm(1)
+            signal.setitimer(signal.ITIMER_REAL, 0.1)
             # Either the reentrant call to wio.write() fails with RuntimeError,
             # or the signal handler raises ZeroDivisionError.
             with self.assertRaises((ZeroDivisionError, RuntimeError)) as cm:
@@ -2992,7 +2992,7 @@ class SignalsTest(unittest.TestCase):
         try:
             rio = self.io.open(r, **fdopen_kwargs)
             os.write(w, b"foo")
-            signal.alarm(1)
+            signal.setitimer(signal.ITIMER_REAL, 0.1)
             # Expected behaviour:
             # - first raw read() returns partial b"foo"
             # - second raw read() returns EINTR
@@ -3036,13 +3036,13 @@ class SignalsTest(unittest.TestCase):
         t.daemon = True
         def alarm1(sig, frame):
             signal.signal(signal.SIGALRM, alarm2)
-            signal.alarm(1)
+            signal.setitimer(signal.ITIMER_REAL, 0.1)
         def alarm2(sig, frame):
             t.start()
         signal.signal(signal.SIGALRM, alarm1)
         try:
             wio = self.io.open(w, **fdopen_kwargs)
-            signal.alarm(1)
+            signal.setitimer(signal.ITIMER_REAL, 0.1)
             # Expected behaviour:
             # - first raw write() is partial (because of the limited pipe buffer
             #   and the first alarm)

Misc/NEWS

@@ -10,6 +10,11 @@ What's New in Python 3.3.0 Beta 1?
 Core and Builtins
 -----------------
 
+- Issue #12268: File readline, readlines and read() or readall() methods
+  no longer lose data when an underlying read system call is interrupted.
+  IOError is no longer raised due to a read system call returning EINTR
+  from within these methods.
+
 - Issue #11626: Add _SizeT functions to stable ABI.
 
 - Issue #15146: Add PyType_FromSpecWithBases. Patch by Robin Schreiber.

Modules/_io/_iomodule.h

@@ -57,6 +57,11 @@ extern Py_ssize_t _PyIO_find_line_ending(
     int translated, int universal, PyObject *readnl,
     int kind, char *start, char *end, Py_ssize_t *consumed);
 
+/* Return 1 if an EnvironmentError with errno == EINTR is set (and then
+   clears the error indicator), 0 otherwise.
+   Should only be called when PyErr_Occurred() is true.
+*/
+extern int _PyIO_trap_eintr(void);
 
 #define DEFAULT_BUFFER_SIZE (8 * 1024)  /* bytes */
 

Modules/_io/bufferedio.c

@@ -746,8 +746,8 @@ _buffered_init(buffered *self)
    clears the error indicator), 0 otherwise.
    Should only be called when PyErr_Occurred() is true.
 */
-static int
-_trap_eintr(void)
+int
+_PyIO_trap_eintr(void)
 {
     static PyObject *eintr_int = NULL;
     PyObject *typ, *val, *tb;
@@ -1396,7 +1396,7 @@ _bufferedreader_raw_read(buffered *self, char *start, Py_ssize_t len)
     */
     do {
         res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_readinto, memobj, NULL);
-    } while (res == NULL && _trap_eintr());
+    } while (res == NULL && _PyIO_trap_eintr());
     Py_DECREF(memobj);
     if (res == NULL)
         return -1;
@@ -1850,7 +1850,7 @@ _bufferedwriter_raw_write(buffered *self, char *start, Py_ssize_t len)
         errno = 0;
         res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_write, memobj, NULL);
         errnum = errno;
-    } while (res == NULL && _trap_eintr());
+    } while (res == NULL && _PyIO_trap_eintr());
     Py_DECREF(memobj);
     if (res == NULL)
         return -1;

Modules/_io/fileio.c

@@ -670,6 +670,13 @@ fileio_readall(fileio *self)
         if (n == 0)
             break;
         if (n < 0) {
+            if (errno == EINTR) {
+                if (PyErr_CheckSignals()) {
+                    Py_DECREF(result);
+                    return NULL;
+                }
+                continue;
+            }
             if (total > 0)
                 break;
             if (errno == EAGAIN) {

Modules/_io/iobase.c

@@ -474,11 +474,15 @@ iobase_readline(PyObject *self, PyObject *args)
         PyObject *b;
 
         if (has_peek) {
-            _Py_IDENTIFIER(peek);
             PyObject *readahead = _PyObject_CallMethodId(self, &PyId_peek, "i", 1);
-
-            if (readahead == NULL)
+            if (readahead == NULL) {
+                /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+                   when EINTR occurs so we needn't do it ourselves. */
+                if (_PyIO_trap_eintr()) {
+                    continue;
+                }
                 goto fail;
+            }
             if (!PyBytes_Check(readahead)) {
                 PyErr_Format(PyExc_IOError,
                              "peek() should have returned a bytes object, "
@@ -511,8 +515,14 @@ iobase_readline(PyObject *self, PyObject *args)
         }
 
         b = _PyObject_CallMethodId(self, &PyId_read, "n", nreadahead);
-        if (b == NULL)
+        if (b == NULL) {
+            /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+               when EINTR occurs so we needn't do it ourselves. */
+            if (_PyIO_trap_eintr()) {
+                continue;
+            }
             goto fail;
+        }
         if (!PyBytes_Check(b)) {
             PyErr_Format(PyExc_IOError,
                          "read() should have returned a bytes object, "
@@ -827,6 +837,11 @@ rawiobase_readall(PyObject *self, PyObject *args)
         PyObject *data = _PyObject_CallMethodId(self, &PyId_read,
                                                 "i", DEFAULT_BUFFER_SIZE);
         if (!data) {
+            /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+               when EINTR occurs so we needn't do it ourselves. */
+            if (_PyIO_trap_eintr()) {
+                continue;
+            }
             Py_DECREF(chunks);
             return NULL;
         }

Modules/_io/textio.c

@@ -1560,8 +1560,14 @@ textiowrapper_read(textio *self, PyObject *args)
         /* Keep reading chunks until we have n characters to return */
         while (remaining > 0) {
             res = textiowrapper_read_chunk(self, remaining);
-            if (res < 0)
+            if (res < 0) {
+                /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+                   when EINTR occurs so we needn't do it ourselves. */
+                if (_PyIO_trap_eintr()) {
+                    continue;
+                }
                 goto fail;
+            }
             if (res == 0)  /* EOF */
                 break;
             if (chunks == NULL) {
@@ -1728,8 +1734,14 @@ _textiowrapper_readline(textio *self, Py_ssize_t limit)
         while (!self->decoded_chars ||
                !PyUnicode_GET_LENGTH(self->decoded_chars)) {
             res = textiowrapper_read_chunk(self, 0);
-            if (res < 0)
+            if (res < 0) {
+                /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+                   when EINTR occurs so we needn't do it ourselves. */
+                if (_PyIO_trap_eintr()) {
+                    continue;
+                }
                 goto error;
+            }
             if (res == 0)
                 break;
         }