From 8f49909e9e5245782bbb14d6468f1c7684229f76 Mon Sep 17 00:00:00 2001
From: Adam Sutton <dev@adamsutton.me.uk>
Date: Sat, 9 Feb 2013 23:18:28 +0000
Subject: [PATCH] Fix #1608 - atomic: add workaround for missing intrinsic
 atomic ops.

---
 configure       |  5 +++++
 src/atomic.h    | 30 ++++++++++++++++++++++++------
 src/main.c      |  2 ++
 src/tvheadend.h |  1 +
 4 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/configure b/configure
index 1b618cea..3d3ec68f 100755
--- a/configure
+++ b/configure
@@ -54,6 +54,11 @@ check_cc_option sse2
 check_cc_snippet getloadavg '#include <stdlib.h> 
 void test() { getloadavg(NULL,0); }'
 
+check_cc_snippet atomic64 '#include <stdint.h>
+uint64_t test(uint64_t *ptr){
+return __sync_fetch_and_add(ptr, 1);
+}'
+
 #
 # Python
 #
diff --git a/src/atomic.h b/src/atomic.h
index f4b8c991..db68ca7e 100644
--- a/src/atomic.h
+++ b/src/atomic.h
@@ -33,13 +33,31 @@ atomic_exchange(volatile int *ptr, int new)
 static inline uint64_t
 atomic_add_u64(volatile uint64_t *ptr, uint64_t incr)
 {
+#if ENABLE_ATOMIC64
   return __sync_fetch_and_add(ptr, incr);
-}
-
-static inline uint64_t
-atomic_pre_add_u64(volatile uint64_t *ptr, uint64_t incr)
-{
-  return __sync_add_and_fetch(ptr, incr);
+#else
+  uint64_t ret;
+  pthread_mutex_lock(&atomic_lock);
+  ret = *ptr;
+  *ptr += incr;
+  pthread_mutex_unlock(&atomic_lock);
+  return ret;
+#endif
+}
+
+static inline uint64_t
+atomic_pre_add_u64(volatile uint64_t *ptr, uint64_t incr)
+{
+#if ENABLE_ATOMIC64
+  return __sync_add_and_fetch(ptr, incr);
+#else
+  uint64_t ret;
+  pthread_mutex_lock(&atomic_lock);
+  *ptr += incr;
+  ret = *ptr;
+  pthread_mutex_unlock(&atomic_lock);
+  return ret;
+#endif
 }
 
 static inline uint64_t
diff --git a/src/main.c b/src/main.c
index a9a50651..60c4cc1c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -139,6 +139,7 @@ time_t dispatch_clock;
 pthread_mutex_t global_lock;
 pthread_mutex_t ffmpeg_lock;
 pthread_mutex_t fork_lock;
+pthread_mutex_t atomic_lock;
 
 /*
  * Locals
@@ -574,6 +575,7 @@ main(int argc, char **argv)
   pthread_mutex_init(&ffmpeg_lock, NULL);
   pthread_mutex_init(&fork_lock, NULL);
   pthread_mutex_init(&global_lock, NULL);
+  pthread_mutex_init(&atomic_lock, NULL);
   pthread_mutex_lock(&global_lock);
 
   time(&dispatch_clock);
diff --git a/src/tvheadend.h b/src/tvheadend.h
index 6b0f3ab5..d2f2b4e5 100644
--- a/src/tvheadend.h
+++ b/src/tvheadend.h
@@ -63,6 +63,7 @@ static inline htsmsg_t *tvheadend_capabilities_list(int check)
 extern pthread_mutex_t global_lock;
 extern pthread_mutex_t ffmpeg_lock;
 extern pthread_mutex_t fork_lock;
+extern pthread_mutex_t atomic_lock;
 
 extern int tvheadend_webui_port;
 extern int tvheadend_webui_debug;