1 files changed, 51 insertions, 0 deletions
diff --git a/dev-lang/python/files/python-2.7.10-semaphore-pid.patch b/dev-lang/python/files/python-2.7.10-semaphore-pid.patch
new file mode 100644
index 000000000000..97fcbd0c49c7
--- /dev/null
+++ b/dev-lang/python/files/python-2.7.10-semaphore-pid.patch
@@ -0,0 +1,51 @@
+Fix for semaphores in pid namespaces
+
+http://bugs.python.org/issue24303
+
+--- a/Modules/_multiprocessing/semaphore.c
++++ b/Modules/_multiprocessing/semaphore.c
+@@ -7,6 +7,7 @@
+  */
+ 
+ #include "multiprocessing.h"
++#include <time.h>
+ 
+ enum { RECURSIVE_MUTEX, SEMAPHORE };
+ 
+@@ -419,7 +420,7 @@ semlock_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+ {
+     char buffer[256];
+     SEM_HANDLE handle = SEM_FAILED;
+-    int kind, maxvalue, value;
++    int kind, maxvalue, value, try;
+     PyObject *result;
+     static char *kwlist[] = {"kind", "value", "maxvalue", NULL};
+     static int counter = 0;
+@@ -433,10 +434,24 @@ semlock_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
+         return NULL;
+     }
+ 
+-    PyOS_snprintf(buffer, sizeof(buffer), "/mp%ld-%d", (long)getpid(), counter++);
++    /* With pid namespaces, we may have multiple processes with the same pid.
++     * Instead of relying on the pid to be unique, we use the microseconds time
++     * to attempt to a unique filename. */
++    for (try = 0; try < 100; ++try) {
++        struct timespec tv;
++        long arbitrary = clock_gettime(CLOCK_REALTIME, &tv) ? 0 : tv.tv_nsec;
++        PyOS_snprintf(buffer, sizeof(buffer), "/mp%ld-%d-%ld",
++                      (long)getpid(),
++                      counter++,
++                      arbitrary);
++        SEM_CLEAR_ERROR();
++        handle = SEM_CREATE(buffer, value, maxvalue);
++        if (handle != SEM_FAILED)
++            break;
++        else if (errno != EEXIST)
++            goto failure;
++    }
+ 
+-    SEM_CLEAR_ERROR();
+-    handle = SEM_CREATE(buffer, value, maxvalue);
+     /* On Windows we should fail if GetLastError()==ERROR_ALREADY_EXISTS */
+     if (handle == SEM_FAILED || SEM_GET_LAST_ERROR() != 0)
+         goto failure;