From 00e513f5c18fdd983364f9781d90835a9ee7a3de Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Mon, 3 Mar 2014 13:58:16 -0600
Subject: [PATCH 01/21] partway through implementing OPA using C11

---
 src/opa_primitives.h             |   2 +
 src/primitives/opa_c11_atomics.h | 125 +++++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 src/primitives/opa_c11_atomics.h

diff --git a/src/opa_primitives.h b/src/opa_primitives.h
index 8e5d40b..8a4e220 100644
--- a/src/opa_primitives.h
+++ b/src/opa_primitives.h
@@ -112,6 +112,8 @@
 #include "primitives/opa_gcc_sicortex.h"
 #elif defined(OPA_HAVE_GCC_INTRINSIC_ATOMICS)
 #include "primitives/opa_gcc_intrinsics.h"
+#elif defined(OPA_HAVE_C11_ATOMICS)
+#include "primitives/opa_c11_atomics.h"
 #elif defined(OPA_HAVE_SUN_ATOMIC_OPS)
 #include "primitives/opa_sun_atomic_ops.h"
 #elif defined(OPA_HAVE_NT_INTRINSICS)
diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
new file mode 100644
index 0000000..11ae382
--- /dev/null
+++ b/src/primitives/opa_c11_atomics.h
@@ -0,0 +1,125 @@
+/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
+/*  
+ *  (C) 2008 by Argonne National Laboratory.
+ *      See COPYRIGHT in top-level directory.
+ */
+
+/* FIXME needs to be converted to new style functions with OPA_int_t/OPA_ptr_t-types */
+#ifndef OPA_C11_ATOMICS_H_INCLUDED
+#define OPA_C11_ATOMICS_H_INCLUDED
+
+#ifdef __STDC_NO_ATOMICS__
+#error stdatomic header is not available.
+#else
+#include <stdatomic.h>
+#endif
+
+#ifndef ATOMIC_INT_LOCK_FREE
+#error atomic_int is not lock-free.
+#else
+typedef atomic_int OPA_int_t;
+#endif
+
+#ifndef ATOMIC_POINTER_LOCK_FREE
+#error atomic_pointer is not lock-free.
+#else
+/* TODO Is this really the right type to use here? */
+typedef atomic_intptr_t OPA_ptr_t;
+#endif
+
+#define OPA_INT_T_INITIALIZER(val_) ATOMIC_VAR_INIT(val_)
+#define OPA_PTR_T_INITIALIZER(val_) ATOMIC_VAR_INIT(val_)
+
+static _opa_inline int OPA_load_int(_opa_const OPA_int_t *ptr)
+{
+    return atomic_load_explicit(ptr, memory_order_relaxed);
+}
+
+static _opa_inline void OPA_store_int(OPA_int_t *ptr, int val)
+{
+    atomic_store_explicit(ptr, val, memory_order_relaxed);
+}
+
+static _opa_inline void *OPA_load_ptr(_opa_const OPA_ptr_t *ptr)
+{
+    return atomic_load_explicit(ptr, memory_order_relaxed);
+}
+
+static _opa_inline void OPA_store_ptr(OPA_ptr_t *ptr, void *val)
+{
+    atomic_store_explicit(ptr, val, memory_order_relaxed);
+}
+
+static _opa_inline int OPA_load_acquire_int(_opa_const OPA_int_t *ptr)
+{
+    return atomic_load_explicit(ptr, memory_order_acquire);
+}
+
+static _opa_inline void OPA_store_release_int(OPA_int_t *ptr, int val)
+{
+    atomic_store_explicit(ptr, val, memory_order_release);
+}
+
+static _opa_inline void *OPA_load_acquire_ptr(_opa_const OPA_ptr_t *ptr)
+{
+    return atomic_load_explicit(ptr, memory_order_acquire);
+}
+
+static _opa_inline void OPA_store_release_ptr(OPA_ptr_t *ptr, void *val)
+{
+    atomic_store_explicit(ptr, val, memory_order_release);
+}
+
+static _opa_inline int OPA_fetch_and_add_int(OPA_int_t *ptr, int val)
+{
+    return atomic_fetch_add_explicit(ptr, val, memory_order_relaxed);
+}
+
+static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
+{
+    return (1 == atomic_fetch_add_explicit(ptr, -1, memory_order_relaxed));
+}
+
+#define OPA_fetch_and_incr_int_by_faa OPA_fetch_and_incr_int
+#define OPA_fetch_and_decr_int_by_faa OPA_fetch_and_decr_int
+#define OPA_add_int_by_faa OPA_add_int
+#define OPA_incr_int_by_fai OPA_incr_int
+#define OPA_decr_int_by_fad OPA_decr_int
+
+
+static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
+{
+    return __sync_val_compare_and_swap(&ptr->v, oldv, newv);
+}
+
+static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
+{
+    return __sync_val_compare_and_swap(&ptr->v, oldv, newv);
+}
+
+#ifdef SYNC_LOCK_TEST_AND_SET_IS_SWAP
+static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)
+{
+    return __sync_lock_test_and_set(&ptr->v, val);
+}
+
+static _opa_inline int OPA_swap_int(OPA_int_t *ptr, int val)
+{
+    return __sync_lock_test_and_set(&ptr->v, val);
+}
+
+#else
+#define OPA_swap_ptr_by_cas OPA_swap_ptr
+#define OPA_swap_int_by_cas OPA_swap_int 
+#endif
+
+#define OPA_write_barrier()      __sync_synchronize()
+#define OPA_read_barrier()       __sync_synchronize()
+#define OPA_read_write_barrier() __sync_synchronize()
+#define OPA_compiler_barrier()   __asm__ __volatile__  ( ""  ::: "memory" )
+
+
+
+#include"opa_emulated.h"
+
+#endif /* OPA_C11_ATOMICS_H_INCLUDED */

From ccd1d2855f66405cbea7cac97b4d961aefffc5c2 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Mon, 3 Mar 2014 14:11:04 -0600
Subject: [PATCH 02/21] finish off impl of existing features; removed
 emulation.  need to add missing stuff.

---
 src/primitives/opa_c11_atomics.h | 37 +++++++++++---------------------
 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 11ae382..0d7a035 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -1,6 +1,7 @@
 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
 /*  
  *  (C) 2008 by Argonne National Laboratory.
+ *  (C) 2014 by Argonne National Laboratory, Leadership Computing Facility.
  *      See COPYRIGHT in top-level directory.
  */
 
@@ -80,46 +81,32 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
     return (1 == atomic_fetch_add_explicit(ptr, -1, memory_order_relaxed));
 }
 
-#define OPA_fetch_and_incr_int_by_faa OPA_fetch_and_incr_int
-#define OPA_fetch_and_decr_int_by_faa OPA_fetch_and_decr_int
-#define OPA_add_int_by_faa OPA_add_int
-#define OPA_incr_int_by_fai OPA_incr_int
-#define OPA_decr_int_by_fad OPA_decr_int
-
-
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 {
-    return __sync_val_compare_and_swap(&ptr->v, oldv, newv);
+    return atomic_compare_exchange_strong_explicit(ptr, &oldv, &newv, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
-    return __sync_val_compare_and_swap(&ptr->v, oldv, newv);
+    return atomic_compare_exchange_strong_explicit(ptr, &oldv, &newv, memory_order_relaxed);
 }
 
-#ifdef SYNC_LOCK_TEST_AND_SET_IS_SWAP
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)
 {
-    return __sync_lock_test_and_set(&ptr->v, val);
+    return atomic_exchange_explicit(ptr, val, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_swap_int(OPA_int_t *ptr, int val)
 {
-    return __sync_lock_test_and_set(&ptr->v, val);
+    return atomic_exchange_explicit(ptr, val, memory_order_relaxed);
 }
 
-#else
-#define OPA_swap_ptr_by_cas OPA_swap_ptr
-#define OPA_swap_int_by_cas OPA_swap_int 
-#endif
-
-#define OPA_write_barrier()      __sync_synchronize()
-#define OPA_read_barrier()       __sync_synchronize()
-#define OPA_read_write_barrier() __sync_synchronize()
-#define OPA_compiler_barrier()   __asm__ __volatile__  ( ""  ::: "memory" )
-
-
-
-#include"opa_emulated.h"
+/* TODO: write/read use of release/acquire might be backwards. */
+#define OPA_write_barrier()      atomic_thread_fence(memory_order_release);
+#define OPA_read_barrier()       atomic_thread_fence(memory_order_acquire);
+#define OPA_read_write_barrier() atomic_thread_fence(memory_order_acq_rel);
+/* FYI: According to C11 7.17.4.2 NOTE 2, atomic_signal_fence acts as
+ *      a compiler barrier.  Note sure how memory_order affects this. */
+#define OPA_compiler_barrier()   atomic_signal_fence(memory_order_acq_rel);
 
 #endif /* OPA_C11_ATOMICS_H_INCLUDED */

From 9bb6bd5fb1efc9c2b15b299ea0b5dff61dfd3714 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 11:57:51 -0800
Subject: [PATCH 03/21] implement the rest of the operations found in
 opa_unsafe.h

---
 src/primitives/opa_c11_atomics.h | 34 ++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 0d7a035..e677480 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -70,25 +70,51 @@ static _opa_inline void OPA_store_release_ptr(OPA_ptr_t *ptr, void *val)
 {
     atomic_store_explicit(ptr, val, memory_order_release);
 }
+static _opa_inline void OPA_add_int(OPA_int_t *ptr, int val)
+{
+    atomic_fetch_add_explicit(ptr, val, memory_order_relaxed);
+}
 
 static _opa_inline int OPA_fetch_and_add_int(OPA_int_t *ptr, int val)
 {
     return atomic_fetch_add_explicit(ptr, val, memory_order_relaxed);
 }
 
+static _opa_inline int OPA_fetch_and_decr_int(OPA_int_t *ptr)
+{
+    return atomic_fetch_add_explicit(ptr, -1, memory_order_relaxed);
+}
+
+static _opa_inline int OPA_fetch_and_incr_int(OPA_int_t *ptr)
+{
+    return atomic_fetch_add_explicit(ptr, 1, memory_order_relaxed);
+}
+
+static _opa_inline void OPA_incr_int(OPA_int_t *ptr)
+{
+    atomic_fetch_add_explicit(ptr, 1, memory_order_relaxed);
+}
+
+static _opa_inline void OPA_decr_int(OPA_int_t *ptr)
+{
+    atomic_fetch_add_explicit(ptr, -1, memory_order_relaxed);
+}
+
 static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 {
     return (1 == atomic_fetch_add_explicit(ptr, -1, memory_order_relaxed));
 }
 
+/* Dave Goodell says weak is fine.  OpenPA does not expect strong. */
+
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 {
-    return atomic_compare_exchange_strong_explicit(ptr, &oldv, &newv, memory_order_relaxed);
+    return atomic_compare_exchange_weak_explicit(ptr, &oldv, &newv, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
-    return atomic_compare_exchange_strong_explicit(ptr, &oldv, &newv, memory_order_relaxed);
+    return atomic_compare_exchange_weak_explicit(ptr, &oldv, &newv, memory_order_relaxed);
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)
@@ -102,8 +128,8 @@ static _opa_inline int OPA_swap_int(OPA_int_t *ptr, int val)
 }
 
 /* TODO: write/read use of release/acquire might be backwards. */
-#define OPA_write_barrier()      atomic_thread_fence(memory_order_release);
-#define OPA_read_barrier()       atomic_thread_fence(memory_order_acquire);
+#define OPA_write_barrier()      atomic_thread_fence(memory_order_acq_rel);
+#define OPA_read_barrier()       atomic_thread_fence(memory_order_acq_rel);
 #define OPA_read_write_barrier() atomic_thread_fence(memory_order_acq_rel);
 /* FYI: According to C11 7.17.4.2 NOTE 2, atomic_signal_fence acts as
  *      a compiler barrier.  Note sure how memory_order affects this. */

From 13711b7756c579a9e454626e289a8a316a654aad Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 12:00:48 -0800
Subject: [PATCH 04/21] choose C11 atomics before anything else (besides
 unsafe)

---
 src/opa_primitives.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/opa_primitives.h b/src/opa_primitives.h
index 8a4e220..f56474e 100644
--- a/src/opa_primitives.h
+++ b/src/opa_primitives.h
@@ -98,9 +98,11 @@
 #if defined(OPA_USE_UNSAFE_PRIMITIVES)
 /* comes first to permit user overrides in the style of NDEBUG */
 #include "primitives/opa_unsafe.h"
-#elif   defined(OPA_HAVE_GCC_AND_POWERPC_ASM)
+#elif defined(OPA_HAVE_C11_ATOMICS)
+#include "primitives/opa_c11_atomics.h"
+#elif defined(OPA_HAVE_GCC_AND_POWERPC_ASM)
 #include "primitives/opa_gcc_ppc.h"
-#elif   defined(OPA_HAVE_GCC_AND_ARM_ASM)
+#elif defined(OPA_HAVE_GCC_AND_ARM_ASM)
 #include "primitives/opa_gcc_arm.h"
 #elif defined(OPA_HAVE_GCC_X86_32_64)
 #include "primitives/opa_gcc_intel_32_64.h"
@@ -112,8 +114,6 @@
 #include "primitives/opa_gcc_sicortex.h"
 #elif defined(OPA_HAVE_GCC_INTRINSIC_ATOMICS)
 #include "primitives/opa_gcc_intrinsics.h"
-#elif defined(OPA_HAVE_C11_ATOMICS)
-#include "primitives/opa_c11_atomics.h"
 #elif defined(OPA_HAVE_SUN_ATOMIC_OPS)
 #include "primitives/opa_sun_atomic_ops.h"
 #elif defined(OPA_HAVE_NT_INTRINSICS)

From bfc89733ee0c0a66c5bdf550381d0c24f63bd94f Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 12:25:16 -0800
Subject: [PATCH 05/21] add some configure magic for C11 impl

---
 configure.ac                     | 1 +
 src/primitives/opa_c11_atomics.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 3e4434e..8465771 100644
--- a/configure.ac
+++ b/configure.ac
@@ -341,6 +341,7 @@ dnl without AC_TRY_RUN().
         OPA_TRY_PRIMITIVE_HEADER([opa_gcc_sicortex.h], [GCC_AND_SICORTEX_ASM], [gcc SiCortex atomics])
     fi
 
+    OPA_TRY_PRIMITIVE_HEADER([opa_c11_atomics.h], [C11_ATOMICS], [C11 atomics])
     OPA_TRY_PRIMITIVE_HEADER([opa_gcc_intrinsics.h], [GCC_INTRINSIC_ATOMICS], [gcc atomic intrinsics])
     OPA_TRY_PRIMITIVE_HEADER([opa_nt_intrinsics.h], [NT_INTRINSICS], [Windows NT atomic intrinsics])
     OPA_TRY_PRIMITIVE_HEADER([opa_sun_atomic_ops.h], [SUN_ATOMIC_OPS], [Sun atomic operations library])
diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index e677480..03af1aa 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -127,7 +127,7 @@ static _opa_inline int OPA_swap_int(OPA_int_t *ptr, int val)
     return atomic_exchange_explicit(ptr, val, memory_order_relaxed);
 }
 
-/* TODO: write/read use of release/acquire might be backwards. */
+/* Dave says that read/write don't match acq/rel perfectly so we use heavy hammer. */
 #define OPA_write_barrier()      atomic_thread_fence(memory_order_acq_rel);
 #define OPA_read_barrier()       atomic_thread_fence(memory_order_acq_rel);
 #define OPA_read_write_barrier() atomic_thread_fence(memory_order_acq_rel);

From 8e6dc9d0e52eca9af4b0ecb84c4e9561eb4aa682 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 13:49:36 -0800
Subject: [PATCH 06/21] fix a pass-by-val/ref bug and add a bunch of explicit
 casts for void* <-> intptr_t

---
 src/primitives/opa_c11_atomics.h | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 03af1aa..9b9d566 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -33,7 +33,7 @@ typedef atomic_intptr_t OPA_ptr_t;
 
 static _opa_inline int OPA_load_int(_opa_const OPA_int_t *ptr)
 {
-    return atomic_load_explicit(ptr, memory_order_relaxed);
+    return (void*)atomic_load_explicit(ptr, memory_order_relaxed);
 }
 
 static _opa_inline void OPA_store_int(OPA_int_t *ptr, int val)
@@ -43,12 +43,12 @@ static _opa_inline void OPA_store_int(OPA_int_t *ptr, int val)
 
 static _opa_inline void *OPA_load_ptr(_opa_const OPA_ptr_t *ptr)
 {
-    return atomic_load_explicit(ptr, memory_order_relaxed);
+    return (void*)atomic_load_explicit(ptr, memory_order_relaxed);
 }
 
 static _opa_inline void OPA_store_ptr(OPA_ptr_t *ptr, void *val)
 {
-    atomic_store_explicit(ptr, val, memory_order_relaxed);
+    atomic_store_explicit(ptr, (intptr_t)val, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_load_acquire_int(_opa_const OPA_int_t *ptr)
@@ -63,13 +63,14 @@ static _opa_inline void OPA_store_release_int(OPA_int_t *ptr, int val)
 
 static _opa_inline void *OPA_load_acquire_ptr(_opa_const OPA_ptr_t *ptr)
 {
-    return atomic_load_explicit(ptr, memory_order_acquire);
+    return (void*)atomic_load_explicit(ptr, memory_order_acquire);
 }
 
 static _opa_inline void OPA_store_release_ptr(OPA_ptr_t *ptr, void *val)
 {
-    atomic_store_explicit(ptr, val, memory_order_release);
+    atomic_store_explicit(ptr, (intptr_t)val, memory_order_release);
 }
+
 static _opa_inline void OPA_add_int(OPA_int_t *ptr, int val)
 {
     atomic_fetch_add_explicit(ptr, val, memory_order_relaxed);
@@ -109,17 +110,17 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 {
-    return atomic_compare_exchange_weak_explicit(ptr, &oldv, &newv, memory_order_relaxed);
+    return atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
-    return atomic_compare_exchange_weak_explicit(ptr, &oldv, &newv, memory_order_relaxed);
+    return atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)
 {
-    return atomic_exchange_explicit(ptr, val, memory_order_relaxed);
+    return (void*)atomic_exchange_explicit(ptr, (intptr_t)val, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_swap_int(OPA_int_t *ptr, int val)

From 2df63762cefbb0086497ec84867aec6d1e71860b Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 13:53:10 -0800
Subject: [PATCH 07/21] remove incorrect casting

---
 src/primitives/opa_c11_atomics.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 9b9d566..0bde8e6 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -25,6 +25,7 @@ typedef atomic_int OPA_int_t;
 #error atomic_pointer is not lock-free.
 #else
 /* TODO Is this really the right type to use here? */
+#include <stdint.h>
 typedef atomic_intptr_t OPA_ptr_t;
 #endif
 
@@ -33,7 +34,7 @@ typedef atomic_intptr_t OPA_ptr_t;
 
 static _opa_inline int OPA_load_int(_opa_const OPA_int_t *ptr)
 {
-    return (void*)atomic_load_explicit(ptr, memory_order_relaxed);
+    return atomic_load_explicit(ptr, memory_order_relaxed);
 }
 
 static _opa_inline void OPA_store_int(OPA_int_t *ptr, int val)
@@ -115,7 +116,7 @@ static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
-    return atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
+    return atomic_compare_exchange_weak_explicit(ptr, &oldv, newv, memory_order_relaxed, memory_order_relaxed);
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)

From df0d39c99f146ba850c6d426e2e15cfb6f71bcbf Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 14:19:16 -0800
Subject: [PATCH 08/21] add FIXME related to CAS

---
 src/primitives/opa_c11_atomics.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 0bde8e6..066fe1b 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -111,11 +111,13 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 {
+    /* FIXME return value */
     return atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
+    /* FIXME return value */
     return atomic_compare_exchange_weak_explicit(ptr, &oldv, newv, memory_order_relaxed, memory_order_relaxed);
 }
 

From 298e0d63ff81fa5efda7aa1e32e0a0a69f7248cc Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 4 Mar 2014 16:11:47 -0800
Subject: [PATCH 09/21] resolve issues with CAS return value by resorting to
 not-actually-atomic impl

---
 src/primitives/opa_c11_atomics.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 066fe1b..ba3a165 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -111,14 +111,18 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
 {
-    /* FIXME return value */
-    return atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
+    /* FIXME This is not safe at all but C11 does not appear to give me any other choice. */
+    void * before = atomic_load_explicit(ptr, memory_order_relaxed);
+    atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
+    return before;
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
 {
-    /* FIXME return value */
-    return atomic_compare_exchange_weak_explicit(ptr, &oldv, newv, memory_order_relaxed, memory_order_relaxed);
+    /* FIXME This is not safe at all but C11 does not appear to give me any other choice. */
+    int before = atomic_load_explicit(ptr, memory_order_relaxed);
+    atomic_compare_exchange_weak_explicit(ptr, &oldv, newv, memory_order_relaxed, memory_order_relaxed);
+    return before;
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)

From 4e7aa022f9f35b31f0a2f8fa8c404d28019777cd Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Wed, 5 Mar 2014 14:16:11 -0500
Subject: [PATCH 10/21] learned about returning old value in expected but not
 able to get correct results yet

---
 src/primitives/opa_c11_atomics.h | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index ba3a165..b3ee37a 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -109,20 +109,18 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 
 /* Dave Goodell says weak is fine.  OpenPA does not expect strong. */
 
-static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *oldv, void *newv)
+#include <stdbool.h>
+
+static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *comparand, void *swaperand)
 {
-    /* FIXME This is not safe at all but C11 does not appear to give me any other choice. */
-    void * before = atomic_load_explicit(ptr, memory_order_relaxed);
-    atomic_compare_exchange_weak_explicit(ptr, (intptr_t*)&oldv, (intptr_t)newv, memory_order_relaxed, memory_order_relaxed);
-    return before;
+    _Bool rc = atomic_compare_exchange_strong_explicit(ptr, (intptr_t*)&comparand, (intptr_t)swaperand, memory_order_relaxed, memory_order_relaxed);
+    return (rc == false ? comparand : swaperand);
 }
 
-static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int oldv, int newv)
+static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int comparand, int swaperand)
 {
-    /* FIXME This is not safe at all but C11 does not appear to give me any other choice. */
-    int before = atomic_load_explicit(ptr, memory_order_relaxed);
-    atomic_compare_exchange_weak_explicit(ptr, &oldv, newv, memory_order_relaxed, memory_order_relaxed);
-    return before;
+    _Bool rc = atomic_compare_exchange_strong_explicit(ptr, &comparand, swaperand, memory_order_relaxed, memory_order_relaxed);
+    return (rc == false ? comparand : swaperand);
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)

From 320d966a26205d956e9b7a42df35e764632a611f Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 18 Mar 2014 16:33:17 -0500
Subject: [PATCH 11/21] add c11 test to automake and git

---
 test/Makefile.am |  3 ++-
 test/test_c11.c  | 58 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 test/test_c11.c

diff --git a/test/Makefile.am b/test/Makefile.am
index 9efd79c..40a7746 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -3,7 +3,7 @@
 #  (C) 2008 by Argonne National Laboratory.
 #      See COPYRIGHT in top-level directory.
 
-TESTS = sanity test_primitives test_barriers test_queue
+TESTS = sanity test_primitives test_barriers test_queue test_c11
 
 check_PROGRAMS = $(TESTS)
 
@@ -15,5 +15,6 @@ sanity_SOURCES = sanity.c
 test_primitives_SOURCES = test_primitives.c opa_test.h
 test_barriers_SOURCES = test_barriers.c opa_test.h
 test_queue_SOURCES = test_queue.c opa_test.h
+test_c11_SOURCES = test_c11.c
 
 AM_CPPFLAGS = -I$(top_srcdir)/src
diff --git a/test/test_c11.c b/test/test_c11.c
new file mode 100644
index 0000000..2acc50e
--- /dev/null
+++ b/test/test_c11.c
@@ -0,0 +1,58 @@
+#if __STDC_VERSION__ < 201112L
+
+#warning Empty test due to lack of C11 support.
+int main(void) { return 1; }
+
+#else
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdatomic.h>
+
+#include <assert.h>
+
+int main(int argc, char **argv)
+{
+    atomic_int a, b;
+    int c;
+
+    //OPA_store_int(&a, 0);
+    atomic_store_explicit(&a, 0, memory_order_relaxed);
+
+    //OPA_store_int(&b, 1);
+    atomic_store_explicit(&b, 1, memory_order_relaxed);
+
+    //OPA_add_int(&a, 10);
+    atomic_fetch_add_explicit(&a, 10, memory_order_relaxed);
+
+    //assert(10 == OPA_load_int(&a));
+    assert(10 == atomic_load_explicit(&a, memory_order_relaxed));
+
+    //c = OPA_cas_int(&a, 10, 11);
+    {
+      int old = 10;
+      int new = 11;
+      atomic_compare_exchange_weak_explicit(&a, &old, new,
+                                            memory_order_relaxed,
+                                            memory_order_relaxed);
+      c = old;
+    }
+    assert(10 == c);
+
+    //c = OPA_swap_int(&a, OPA_load_int(&b));
+    c = atomic_exchange_explicit(&a,
+                                 atomic_load_explicit(&b, memory_order_relaxed),
+                                 memory_order_relaxed);
+
+    assert(11 == c);
+
+    //assert(1 == OPA_load_int(&a));
+    assert(1 == atomic_load_explicit(&a, memory_order_relaxed));
+
+    printf("success!\n");
+
+    return 0;
+}
+
+#endif

From 9eedd62ab2eb98f07022b39390e383c9d8bb5131 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 18 Mar 2014 16:34:00 -0500
Subject: [PATCH 12/21] fix cas impl.  expected holds old val either way.

---
 src/primitives/opa_c11_atomics.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index b3ee37a..e4dbdc5 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -113,14 +113,14 @@ static _opa_inline int OPA_decr_and_test_int(OPA_int_t *ptr)
 
 static _opa_inline void *OPA_cas_ptr(OPA_ptr_t *ptr, void *comparand, void *swaperand)
 {
-    _Bool rc = atomic_compare_exchange_strong_explicit(ptr, (intptr_t*)&comparand, (intptr_t)swaperand, memory_order_relaxed, memory_order_relaxed);
-    return (rc == false ? comparand : swaperand);
+    atomic_compare_exchange_strong_explicit(ptr, (intptr_t*)&comparand, (intptr_t)swaperand, memory_order_relaxed, memory_order_relaxed);
+    return comparand;
 }
 
 static _opa_inline int OPA_cas_int(OPA_int_t *ptr, int comparand, int swaperand)
 {
-    _Bool rc = atomic_compare_exchange_strong_explicit(ptr, &comparand, swaperand, memory_order_relaxed, memory_order_relaxed);
-    return (rc == false ? comparand : swaperand);
+    atomic_compare_exchange_strong_explicit(ptr, &comparand, swaperand, memory_order_relaxed, memory_order_relaxed);
+    return comparand;
 }
 
 static _opa_inline void *OPA_swap_ptr(OPA_ptr_t *ptr, void *val)

From 689920af1c5da72de77acf3de32b08873fa8c8ce Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Sun, 4 Sep 2016 15:41:19 -0700
Subject: [PATCH 13/21] fix bugs in C11 implementation

1) cannot use const according to clang-3.8
2) ATOMIC_INT_LOCK_FREE (and similar) are named wrong in Clang
   (they have an extra _T_ in the middle) and thus the macros
   fail.  we need to check to see if the macro is defined before
   testing its value.
---
 src/primitives/opa_c11_atomics.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index e4dbdc5..6f6f6ee 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -15,13 +15,13 @@
 #include <stdatomic.h>
 #endif
 
-#ifndef ATOMIC_INT_LOCK_FREE
+#if defined(ATOMIC_INT_LOCK_FREE) && (ATOMIC_INT_LOCK_FREE < 2)
 #error atomic_int is not lock-free.
 #else
 typedef atomic_int OPA_int_t;
 #endif
 
-#ifndef ATOMIC_POINTER_LOCK_FREE
+#if defined(ATOMIC_POINTER_LOCK_FREE) && (ATOMIC_POINTER_LOCK_FREE < 2)
 #error atomic_pointer is not lock-free.
 #else
 /* TODO Is this really the right type to use here? */
@@ -32,7 +32,7 @@ typedef atomic_intptr_t OPA_ptr_t;
 #define OPA_INT_T_INITIALIZER(val_) ATOMIC_VAR_INIT(val_)
 #define OPA_PTR_T_INITIALIZER(val_) ATOMIC_VAR_INIT(val_)
 
-static _opa_inline int OPA_load_int(_opa_const OPA_int_t *ptr)
+static _opa_inline int OPA_load_int(OPA_int_t *ptr)
 {
     return atomic_load_explicit(ptr, memory_order_relaxed);
 }
@@ -42,7 +42,7 @@ static _opa_inline void OPA_store_int(OPA_int_t *ptr, int val)
     atomic_store_explicit(ptr, val, memory_order_relaxed);
 }
 
-static _opa_inline void *OPA_load_ptr(_opa_const OPA_ptr_t *ptr)
+static _opa_inline void *OPA_load_ptr(OPA_ptr_t *ptr)
 {
     return (void*)atomic_load_explicit(ptr, memory_order_relaxed);
 }
@@ -52,7 +52,7 @@ static _opa_inline void OPA_store_ptr(OPA_ptr_t *ptr, void *val)
     atomic_store_explicit(ptr, (intptr_t)val, memory_order_relaxed);
 }
 
-static _opa_inline int OPA_load_acquire_int(_opa_const OPA_int_t *ptr)
+static _opa_inline int OPA_load_acquire_int(OPA_int_t *ptr)
 {
     return atomic_load_explicit(ptr, memory_order_acquire);
 }
@@ -62,7 +62,7 @@ static _opa_inline void OPA_store_release_int(OPA_int_t *ptr, int val)
     atomic_store_explicit(ptr, val, memory_order_release);
 }
 
-static _opa_inline void *OPA_load_acquire_ptr(_opa_const OPA_ptr_t *ptr)
+static _opa_inline void *OPA_load_acquire_ptr(OPA_ptr_t *ptr)
 {
     return (void*)atomic_load_explicit(ptr, memory_order_acquire);
 }

From 6c88ee1ebbe5f41f0ec6a9866994f768c6cc0e93 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Sun, 4 Sep 2016 15:59:47 -0700
Subject: [PATCH 14/21] workaround ATOMIC_*_LOCK_FREE bug in Clang

---
 src/primitives/opa_c11_atomics.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/primitives/opa_c11_atomics.h b/src/primitives/opa_c11_atomics.h
index 6f6f6ee..e221b3c 100644
--- a/src/primitives/opa_c11_atomics.h
+++ b/src/primitives/opa_c11_atomics.h
@@ -15,13 +15,15 @@
 #include <stdatomic.h>
 #endif
 
-#if defined(ATOMIC_INT_LOCK_FREE) && (ATOMIC_INT_LOCK_FREE < 2)
+/* Clang 3.x has a bug in stdatomic.h, wherein there is an extra _T
+ * in the following macros.  It is fixed in Clang 4.x. */
+#if !defined(ATOMIC_INT_LOCK_FREE) && !defined(ATOMIC_INT_T_LOCK_FREE)
 #error atomic_int is not lock-free.
 #else
 typedef atomic_int OPA_int_t;
 #endif
 
-#if defined(ATOMIC_POINTER_LOCK_FREE) && (ATOMIC_POINTER_LOCK_FREE < 2)
+#if !defined(ATOMIC_POINTER_LOCK_FREE) && !defined(ATOMIC_POINTER_T_LOCK_FREE)
 #error atomic_pointer is not lock-free.
 #else
 /* TODO Is this really the right type to use here? */

From cf1cb555f8b998c884eccb5346b114f3b42fa1ec Mon Sep 17 00:00:00 2001
From: "Antonio J. Pena" <apenya@mcs.anl.gov>
Date: Fri, 27 Jun 2014 17:13:27 -0500
Subject: [PATCH 15/21] Updated trac URLs

---
 README       | 2 +-
 configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/README b/README
index bf6ea8b..7553eb8 100644
--- a/README
+++ b/README
@@ -10,7 +10,7 @@ derived from work on the MPICH2 project.
 
 Project documentation and bug tracking can be found at:
 
-  https://trac.mcs.anl.gov/projects/openpa/
+  https://trac.mpich.org/projects/openpa/
 
 If you would like to email questions or discuss topics related to OpenPA
 you can send mail to opa-discuss@lists.mcs.anl.gov.
diff --git a/configure.ac b/configure.ac
index 8465771..03777b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,7 @@
 
 AC_PREREQ(2.62)
 
-AC_INIT([OpenPA], [1.0.4], [https://trac.mcs.anl.gov/projects/openpa/newticket])
+AC_INIT([OpenPA], [1.0.4], [https://trac.mpich.org/projects/openpa/newticket])
 dnl Set the directory that contains support scripts such as install-sh and
 dnl config.guess.  It also contains autoconf macro files.
 AC_CONFIG_AUX_DIR(confdb)

From e0a3ea1e6d32034f39e45d84963fac509c9126f7 Mon Sep 17 00:00:00 2001
From: "Antonio J. Pena" <apenya@mcs.anl.gov>
Date: Fri, 27 Jun 2014 17:15:14 -0500
Subject: [PATCH 16/21] Updated contact information in COPYRIGHT

Fixes #26
---
 COPYRIGHT | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/COPYRIGHT b/COPYRIGHT
index 6f6c81e..065ccfb 100644
--- a/COPYRIGHT
+++ b/COPYRIGHT
@@ -12,10 +12,9 @@ Permission is hereby granted to use, reproduce, prepare derivative works, and
 to redistribute to others.  This software was authored by:
 
 Argonne National Laboratory Group
-D. Goodell:  (630) 252-6082; FAX: (630) 252-5986; e-mail: goodell@mcs.anl.gov
-D. Buntinas: (630) 252-7928; FAX: (630) 252-5986; e-mail: buntinas@mcs.anl.gov
 Mathematics and Computer Science Division
 Argonne National Laboratory, Argonne IL 60439
+Contact: devel@mpich.org
 
 
                               GOVERNMENT LICENSE

From d2f8908954b7292b076d7064783cfffe6af9712e Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Sun, 4 Sep 2016 16:11:36 -0700
Subject: [PATCH 17/21] add Travis script

try various std flags
install autotools
debug travis
add missing script
create dir before using
autotools build failed with c11 flags
brute force debug configure
---
 .travis-install-autotools.sh | 139 +++++++++++++++++++++++++++++++++++
 .travis.yml                  |  49 ++++++++++++
 2 files changed, 188 insertions(+)
 create mode 100755 .travis-install-autotools.sh
 create mode 100644 .travis.yml

diff --git a/.travis-install-autotools.sh b/.travis-install-autotools.sh
new file mode 100755
index 0000000..7b81d66
--- /dev/null
+++ b/.travis-install-autotools.sh
@@ -0,0 +1,139 @@
+#!/bin/sh
+
+set +e
+set -x
+
+os=`uname`
+TRAVIS_ROOT="$1"
+
+case "$os" in
+    Darwin)
+        set +e # do not fail on error
+        brew update
+        brew info autoconf automake libtool
+        brew install autoconf automake libtool
+        brew upgrade autoconf automake libtool
+        which glibtool
+        which glibtoolize
+        glibtool --version
+        ln -s `which glibtool` ${TRAVIS_ROOT}/bin/libtool
+        ln -s `which glibtoolize` ${TRAVIS_ROOT}/bin/libtoolize
+        set -e # restore fail on error
+        ;;
+    Linux)
+        MAKE_JNUM=2
+        M4_VERSION=1.4.17
+        LIBTOOL_VERSION=2.4.6
+        AUTOCONF_VERSION=2.69
+        AUTOMAKE_VERSION=1.15
+
+        cd ${TRAVIS_ROOT}
+        TOOL=m4
+        TDIR=${TOOL}-${M4_VERSION}
+        FILE=${TDIR}.tar.gz
+        BIN=${TRAVIS_ROOT}/bin/${TOOL}
+        if [ -f ${FILE} ] ; then
+          echo ${FILE} already exists! Using existing copy.
+        else
+          wget http://ftp.gnu.org/gnu/${TOOL}/${FILE}
+        fi
+        if [ -d ${TDIR} ] ; then
+          echo ${TDIR} already exists! Using existing copy.
+        else
+          echo Unpacking ${FILE}
+          tar -xzf ${FILE}
+        fi
+        if [ -f ${BIN} ] ; then
+          echo ${BIN} already exists! Skipping build.
+        else
+          cd ${TRAVIS_ROOT}/${TDIR}
+          ./configure CC=cc --prefix=${TRAVIS_ROOT} && make -j ${MAKE_JNUM} && make install
+          if [ "x$?" != "x0" ] ; then
+            echo FAILURE 1
+            exit
+          fi
+        fi
+
+        cd ${TRAVIS_ROOT}
+        TOOL=libtool
+        TDIR=${TOOL}-${LIBTOOL_VERSION}
+        FILE=${TDIR}.tar.gz
+        BIN=${TRAVIS_ROOT}/bin/${TOOL}
+        if [ ! -f ${FILE} ] ; then
+          wget http://ftp.gnu.org/gnu/${TOOL}/${FILE}
+        else
+          echo ${FILE} already exists! Using existing copy.
+        fi
+        if [ ! -d ${TDIR} ] ; then
+          echo Unpacking ${FILE}
+          tar -xzf ${FILE}
+        else
+          echo ${TDIR} already exists! Using existing copy.
+        fi
+        if [ -f ${BIN} ] ; then
+          echo ${BIN} already exists! Skipping build.
+        else
+          cd ${TRAVIS_ROOT}/${TDIR}
+          ./configure CC=cc --prefix=${TRAVIS_ROOT} M4=${TRAVIS_ROOT}/bin/m4 && make -j ${MAKE_JNUM} && make install
+          if [ "x$?" != "x0" ] ; then
+            echo FAILURE 2
+            exit
+          fi
+        fi
+
+        cd ${TRAVIS_ROOT}
+        TOOL=autoconf
+        TDIR=${TOOL}-${AUTOCONF_VERSION}
+        FILE=${TDIR}.tar.gz
+        BIN=${TRAVIS_ROOT}/bin/${TOOL}
+        if [ ! -f ${FILE} ] ; then
+          wget http://ftp.gnu.org/gnu/${TOOL}/${FILE}
+        else
+          echo ${FILE} already exists! Using existing copy.
+        fi
+        if [ ! -d ${TDIR} ] ; then
+          echo Unpacking ${FILE}
+          tar -xzf ${FILE}
+        else
+          echo ${TDIR} already exists! Using existing copy.
+        fi
+        if [ -f ${BIN} ] ; then
+          echo ${BIN} already exists! Skipping build.
+        else
+          cd ${TRAVIS_ROOT}/${TDIR}
+          ./configure CC=cc --prefix=${TRAVIS_ROOT} M4=${TRAVIS_ROOT}/bin/m4 && make -j ${MAKE_JNUM} && make install
+          if [ "x$?" != "x0" ] ; then
+            echo FAILURE 3
+            exit
+          fi
+        fi
+
+        cd ${TRAVIS_ROOT}
+        TOOL=automake
+        TDIR=${TOOL}-${AUTOMAKE_VERSION}
+        FILE=${TDIR}.tar.gz
+        BIN=${TRAVIS_ROOT}/bin/${TOOL}
+        if [ ! -f ${FILE} ] ; then
+          wget http://ftp.gnu.org/gnu/${TOOL}/${FILE}
+        else
+          echo ${FILE} already exists! Using existing copy.
+        fi
+        if [ ! -d ${TDIR} ] ; then
+          echo Unpacking ${FILE}
+          tar -xzf ${FILE}
+        else
+          echo ${TDIR} already exists! Using existing copy.
+        fi
+        if [ -f ${BIN} ] ; then
+          echo ${BIN} already exists! Skipping build.
+        else
+          cd ${TRAVIS_ROOT}/${TDIR}
+          ./configure CC=cc --prefix=${TRAVIS_ROOT} M4=${TRAVIS_ROOT}/bin/m4 && make -j ${MAKE_JNUM} && make install
+          if [ "x$?" != "x0" ] ; then
+            echo FAILURE 4
+            exit
+          fi
+        fi
+        ;;
+esac
+
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..aafd8ea
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,49 @@
+sudo: false
+language: c
+os:
+- linux
+- osx
+compiler:
+- gcc
+- clang
+env:
+  matrix:
+  - OPA_CFLAGS=-std=c89
+  - OPA_CFLAGS=-std=c99
+  - OPA_CFLAGS=-std=c11
+  - OPA_CFLAGS=-std=gnu89
+  - OPA_CFLAGS=-std=gnu99
+  - OPA_CFLAGS=-std=gnu11
+addons:
+  apt:
+    sources:
+    - ubuntu-toolchain-r-test
+    # clang-3.8 comes from this
+    - llvm-toolchain-precise
+    packages:
+    - gcc-4.9
+    - gcc-5
+    - gcc-6
+    - clang-3.8
+install:
+- export WORKING_DIRECTORY=$PWD
+- mkdir -p $WORKING_DIRECTORY/deps
+- export PATH=$WORKING_DIRECTORY/deps/bin:$PATH
+- sh .travis-install-autotools.sh $WORKING_DIRECTORY/deps
+before_script:
+- ./autogen.sh
+script:
+- ./configure CFLAGS=$OPA_CFLAGS
+- make
+- make check
+after_failure:
+- echo "Sad panda"
+- find . -name config.log -exec cat {} ";"
+notifications:
+  email:
+    recipients:
+    - jeff.science@gmail.com
+    on_success:
+    - change
+    on_failure:
+    - always

From af1a04cfc24572b9a5b346c9e92f9861b3ae58fc Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Mon, 19 Sep 2016 16:11:46 -0700
Subject: [PATCH 18/21] declare pthread_yield

---
 test/opa_test.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/opa_test.h b/test/opa_test.h
index 490b916..08c26e1 100644
--- a/test/opa_test.h
+++ b/test/opa_test.h
@@ -20,6 +20,7 @@
 #include <limits.h>
 #include <time.h>
 #if defined(OPA_HAVE_PTHREAD_H)
+#  define _GNU_SOURCE
 #  include <pthread.h>
 #endif /* HAVE_PTHREAD_H */
 

From 95d36c79a349e1935d1c6d3d28f61ae3b5edafdf Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Mon, 19 Sep 2016 16:20:09 -0700
Subject: [PATCH 19/21] older GCC doesn't understand C11

---
 .travis.yml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index aafd8ea..59f4948 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,14 @@ env:
   - OPA_CFLAGS=-std=gnu89
   - OPA_CFLAGS=-std=gnu99
   - OPA_CFLAGS=-std=gnu11
+matrix:
+  allow_failures:
+  - os: linux
+    compiler: gcc
+    env: OPA_CFLAGS=-std=c11
+  - os: linux
+    compiler: gcc
+    env: OPA_CFLAGS=-std=gnu11
 addons:
   apt:
     sources:

From 56f55479da7c273769da7a33abf6dc01f0fd637d Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.science@gmail.com>
Date: Tue, 20 Sep 2016 15:03:47 -0700
Subject: [PATCH 20/21] soft fail on missing C11

---
 test/test_c11.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/test/test_c11.c b/test/test_c11.c
index 2acc50e..43e9a4b 100644
--- a/test/test_c11.c
+++ b/test/test_c11.c
@@ -1,19 +1,15 @@
-#if __STDC_VERSION__ < 201112L
-
-#warning Empty test due to lack of C11 support.
-int main(void) { return 1; }
-
-#else
-
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdbool.h>
-#include <stdatomic.h>
-
 #include <assert.h>
 
+#if __STDC_VERSION__ >= 201112L
+# include <stdbool.h>
+# include <stdatomic.h>
+#endif
+
 int main(int argc, char **argv)
 {
+#if __STDC_VERSION__ >= 201112L
     atomic_int a, b;
     int c;
 
@@ -51,8 +47,9 @@ int main(int argc, char **argv)
     assert(1 == atomic_load_explicit(&a, memory_order_relaxed));
 
     printf("success!\n");
-
+#else
+    printf("C11 not supported!\n");
+#endif
     return 0;
 }
 
-#endif

From 4c2e1874b73782a82efd8436860f299bb95ccdf5 Mon Sep 17 00:00:00 2001
From: Jeff Hammond <jeff.r.hammond@intel.com>
Date: Mon, 29 Apr 2019 16:44:56 -0700
Subject: [PATCH 21/21] remove notifications

---
 .travis.yml | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 59f4948..3aac0aa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -47,11 +47,3 @@ script:
 after_failure:
 - echo "Sad panda"
 - find . -name config.log -exec cat {} ";"
-notifications:
-  email:
-    recipients:
-    - jeff.science@gmail.com
-    on_success:
-    - change
-    on_failure:
-    - always