[pypy-commit] pypy fast-gil: Partial revert of 40e4dd588bd7.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: fast-gil
Changeset: r72225:c43e39223544
Date: 2014-06-25 18:07 +0200
http://bitbucket.org/pypy/pypy/changeset/c43e39223544/

Log:	Partial revert of 40e4dd588bd7.

diff --git a/rpython/translator/c/src/thread_gil.c b/rpython/translator/c/src/thread_gil.c
--- a/rpython/translator/c/src/thread_gil.c
+++ b/rpython/translator/c/src/thread_gil.c
@@ -53,6 +53,11 @@
 void RPyGilAcquire(void)
 {
     /* Acquires the GIL.
+
+       XXX Note: this function saves and restores 'errno'. This is
+       needed for now because it may be *followed* by reading the
+       'errno', although it's kind of bogus: it should be read before
+       calling RPyGilAcquire().
      */
     long old_fastgil = lock_test_and_set(&rpy_fastgil, 1);
 
@@ -63,6 +68,7 @@
     }
     else {
         /* Otherwise, another thread is busy with the GIL. */
+        int old_errno = errno;
 
         /* Register me as one of the threads that is actively waiting
            for the GIL.  The number of such threads is found in
@@ -102,6 +108,8 @@
         }
         atomic_decrement(&rpy_waiting_threads);
         mutex_unlock(&mutex_gil_stealer);
+
+        errno = old_errno;
     }
     assert(RPY_FASTGIL_LOCKED(rpy_fastgil));