diff -r 0d0989359bbb Modules/selectmodule.c
--- a/Modules/selectmodule.c	Sun May 24 16:41:42 2015 -0700
+++ b/Modules/selectmodule.c	Sun May 24 22:23:47 2015 -0700
@@ -194,10 +194,14 @@
     PyObject *ifdlist, *ofdlist, *efdlist;
     PyObject *ret = NULL;
     PyObject *timeout_obj = Py_None;
-    fd_set ifdset, ofdset, efdset;
+    fd_set orig_ifdset, ifdset, ofdset, efdset;
     struct timeval tv, *tvp;
     int imax, omax, emax, max;
     int n;
+    int is_main_thread = _PyOS_IsMainThread();
+    int wakeup_fds[2];
+    int prev_wakeup_fd = -1;
+    char wakeup_signal = 0;
     _PyTime_t timeout, deadline = 0;
 
     /* convert arguments */
@@ -252,6 +256,27 @@
     if ((emax=seq2set(efdlist, &efdset, efd2obj)) < 0)
         goto finally;
 
+    if (is_main_thread) {
+        int flags = 0;
+#ifdef O_NONBLOCK
+        flags |= O_NONBLOCK;
+#endif
+#ifdef O_CLOEXEC
+        flags |= O_CLOEXEC;
+#endif
+        if (pipe2(wakeup_fds, flags)) {
+            PyErr_SetFromErrno(PyExc_OSError);
+            goto finally;
+        }
+        prev_wakeup_fd = PySignal_SetWakeupFd(wakeup_fds[1]);
+        FD_SET(wakeup_fds[0], &ifdset);
+        if (wakeup_fds[0] >= imax) {
+            imax = wakeup_fds[0] + 1;
+        }
+        if (PyErr_CheckSignals())
+            goto finally;
+    }
+
     max = imax;
     if (omax > max) max = omax;
     if (emax > max) max = emax;
@@ -259,28 +284,63 @@
     if (tvp)
         deadline = _PyTime_GetMonotonicClock() + timeout;
 
+    orig_ifdset = ifdset;
     do {
         Py_BEGIN_ALLOW_THREADS
         errno = 0;
         n = select(max, &ifdset, &ofdset, &efdset, tvp);
         Py_END_ALLOW_THREADS
 
-        if (errno != EINTR)
-            break;
+        if (errno == EINTR) {
+            /* select() was interrupted by a signal */
+            if (PyErr_CheckSignals())
+                goto finally;
 
-        /* select() was interrupted by a signal */
-        if (PyErr_CheckSignals())
-            goto finally;
+            if (tvp) {
+                timeout = deadline - _PyTime_GetMonotonicClock();
+                if (timeout < 0) {
+                    n = 0;
+                    break;
+                }
+                _PyTime_AsTimeval_noraise(timeout, &tv, _PyTime_ROUND_CEILING);
+                /* retry select() with the recomputed timeout */
+            }
+            continue;
+        }
 
-        if (tvp) {
-            timeout = deadline - _PyTime_GetMonotonicClock();
-            if (timeout < 0) {
-                n = 0;
+        if (is_main_thread && FD_ISSET(wakeup_fds[0], &ifdset)) {
+            /* Delete fd from everything that will be returned up. */
+            FD_CLR(wakeup_fds[0], &ifdset);
+            n -= 1;
+
+            while (read(wakeup_fds[0], &wakeup_signal, 1) < 0) {
+                if (errno == EAGAIN || errno == EWOULDBLOCK) {
+                    break;
+                } else if (errno == EINTR) {
+                    continue;
+                } else {
+                    PyErr_SetFromErrno(PyExc_OSError);
+                }
+            }
+
+            if (prev_wakeup_fd != -1 && wakeup_signal != 0) {
+                while (write(prev_wakeup_fd, &wakeup_signal, 1) < 0) {
+                    if (errno == EINTR) {
+                        continue;
+                    }
+                    PyErr_SetFromErrno(PyExc_OSError);
+                }
+            }
+            if (PyErr_CheckSignals())
+                goto finally;
+            if (n) {
                 break;
+            } else {
+                ifdset = orig_ifdset;
+                continue;
             }
-            _PyTime_AsTimeval_noraise(timeout, &tv, _PyTime_ROUND_CEILING);
-            /* retry select() with the recomputed timeout */
         }
+        break;
     } while (1);
 
 #ifdef MS_WINDOWS
@@ -311,6 +371,21 @@
     }
 
   finally:
+    if (is_main_thread) {
+        int i;
+        for (i = 0; i < 2; i++) {
+            while (close(wakeup_fds[i]) == -1) {
+                if (errno == EINTR) {
+                    continue;
+                }
+                PyErr_SetFromErrno(PyExc_OSError);
+                Py_CLEAR(ret);
+            }
+        }
+        if (prev_wakeup_fd != -1) {
+            PySignal_SetWakeupFd(prev_wakeup_fd);
+        }
+    }
     reap_obj(rfd2obj);
     reap_obj(wfd2obj);
     reap_obj(efd2obj);