qemu/atomic.h: rename atomic_ to qatomic_

clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:

  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)

Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.

This patch was generated using:

  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done

I manually fixed line-wrap issues and misaligned rST tables.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/include/block/aio.h b/include/block/aio.h
index b2f703f..ec8c5af 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -595,7 +595,7 @@ int64_t aio_compute_timeout(AioContext *ctx);
  */
 static inline void aio_disable_external(AioContext *ctx)
 {
-    atomic_inc(&ctx->external_disable_cnt);
+    qatomic_inc(&ctx->external_disable_cnt);
 }
 
 /**
@@ -608,7 +608,7 @@ static inline void aio_enable_external(AioContext *ctx)
 {
     int old;
 
-    old = atomic_fetch_dec(&ctx->external_disable_cnt);
+    old = qatomic_fetch_dec(&ctx->external_disable_cnt);
     assert(old > 0);
     if (old == 1) {
         /* Kick event loop so it re-arms file descriptors */
@@ -624,7 +624,7 @@ static inline void aio_enable_external(AioContext *ctx)
  */
 static inline bool aio_external_disabled(AioContext *ctx)
 {
-    return atomic_read(&ctx->external_disable_cnt);
+    return qatomic_read(&ctx->external_disable_cnt);
 }
 
 /**
@@ -637,7 +637,7 @@ static inline bool aio_external_disabled(AioContext *ctx)
  */
 static inline bool aio_node_check(AioContext *ctx, bool is_external)
 {
-    return !is_external || !atomic_read(&ctx->external_disable_cnt);
+    return !is_external || !qatomic_read(&ctx->external_disable_cnt);
 }
 
 /**