From: Gregory P. Smith <greg@krypto.org>
Date: Sun, 24 Jun 2012 07:23:47 +0000 (-0700)
Subject: Fixes issue #12268: File readline, readlines and read() or readall() methods
X-Git-Tag: v3.3.0b1~90
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=990a5feba77de7fc5fd5ad5a16f61dc93667f63e;p=python

Fixes 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.
---

990a5feba77de7fc5fd5ad5a16f61dc93667f63e
diff --cc Misc/NEWS
index 1b92b16319,95f66d71ea..c429412788
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,10 -10,11 +10,15 @@@ 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.
 +
  - Issue #15142: Fix reference leak when deallocating instances of types
    created using PyType_FromSpec().
  
diff --cc Modules/_io/_iomodule.h
index 987aac80e5,aa8bfd69dd..0fe90a3b3b
--- a/Modules/_io/_iomodule.h
+++ b/Modules/_io/_iomodule.h
@@@ -55,8 -55,13 +55,13 @@@ extern PyObject *_PyIncrementalNewlineD
     Otherwise, the function will scan further and return garbage. */
  extern Py_ssize_t _PyIO_find_line_ending(
      int translated, int universal, PyObject *readnl,
 -    Py_UNICODE *start, Py_UNICODE *end, Py_ssize_t *consumed);
 +    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 */
  
diff --cc Modules/_io/iobase.c
index b30bbb69a3,2bba1bfd58..dd052ae6e9
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@@ -474,11 -481,15 +474,15 @@@ iobase_readline(PyObject *self, PyObjec
          PyObject *b;
  
          if (has_peek) {
-             _Py_IDENTIFIER(peek);
 -            PyObject *readahead = PyObject_CallMethod(self, "peek", "i", 1);
 +            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, "
@@@ -510,9 -521,15 +514,15 @@@
              Py_DECREF(readahead);
          }
  
 -        b = PyObject_CallMethod(self, "read", "n", nreadahead);
 +        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, "
@@@ -823,10 -835,14 +833,15 @@@ rawiobase_readall(PyObject *self, PyObj
          return NULL;
  
      while (1) {
 -        PyObject *data = PyObject_CallMethod(self, "read",
 -                                             "i", DEFAULT_BUFFER_SIZE);
 +        _Py_IDENTIFIER(read);
 +        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;
          }
diff --cc Modules/_io/textio.c
index 287f165cb0,d86a1c7b6d..d390d5a426
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@@ -1559,9 -1540,15 +1559,15 @@@ textiowrapper_read(textio *self, PyObje
  
          /* Keep reading chunks until we have n characters to return */
          while (remaining > 0) {
 -            res = textiowrapper_read_chunk(self);
 +            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) {
@@@ -1726,10 -1705,16 +1732,16 @@@ _textiowrapper_readline(textio *self, P
          /* First, get some data if necessary */
          res = 1;
          while (!self->decoded_chars ||
 -               !PyUnicode_GET_SIZE(self->decoded_chars)) {
 -            res = textiowrapper_read_chunk(self);
 +               !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;
          }