qga/command: use QEMU atomic primitives

The guest client's use of the glib's g_atomic primitives causes newer
GCC's to barf when built on Travis. As QEMU has its own primitives with
well understood semantics we might as well use them.

The use of atomics was a little inconsistent so I've also ensure the
values are correctly set with atomic primitives at the same time.

I also made the usage of bool consistent while I was at it.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20160930213106.20186-12-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

qga/commands.c

@@ -16,6 +16,7 @@
 #include "qapi/qmp/qerror.h"
 #include "qemu/base64.h"
 #include "qemu/cutils.h"
+#include "qemu/atomic.h"
 
 /* Maximum captured guest-exec out_data/err_data - 16MB */
 #define GUEST_EXEC_MAX_OUTPUT (16*1024*1024)
@@ -82,7 +83,7 @@ struct GuestExecIOData {
     guchar *data;
     gsize size;
     gsize length;
-    gint closed;
+    bool closed;
     bool truncated;
     const char *name;
 };
@@ -93,7 +94,7 @@ struct GuestExecInfo {
     int64_t pid_numeric;
     gint status;
     bool has_output;
-    gint finished;
+    bool finished;
     GuestExecIOData in;
     GuestExecIOData out;
     GuestExecIOData err;
@@ -156,13 +157,13 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err)
 
     ges = g_new0(GuestExecStatus, 1);
 
-    bool finished = g_atomic_int_get(&gei->finished);
+    bool finished = atomic_mb_read(&gei->finished);
 
     /* need to wait till output channels are closed
      * to be sure we captured all output at this point */
     if (gei->has_output) {
-        finished = finished && g_atomic_int_get(&gei->out.closed);
-        finished = finished && g_atomic_int_get(&gei->err.closed);
+        finished = finished && atomic_mb_read(&gei->out.closed);
+        finished = finished && atomic_mb_read(&gei->err.closed);
     }
 
     ges->exited = finished;
@@ -264,7 +265,7 @@ static void guest_exec_child_watch(GPid pid, gint status, gpointer data)
             (int32_t)gpid_to_int64(pid), (uint32_t)status);
 
     gei->status = status;
-    gei->finished = true;
+    atomic_mb_set(&gei->finished, true);
 
     g_spawn_close_pid(pid);
 }
@@ -320,7 +321,7 @@ static gboolean guest_exec_input_watch(GIOChannel *ch,
 done:
     g_io_channel_shutdown(ch, true, NULL);
     g_io_channel_unref(ch);
-    g_atomic_int_set(&p->closed, 1);
+    atomic_mb_set(&p->closed, true);
     g_free(p->data);
 
     return false;
@@ -374,7 +375,7 @@ static gboolean guest_exec_output_watch(GIOChannel *ch,
 close:
     g_io_channel_shutdown(ch, true, NULL);
     g_io_channel_unref(ch);
-    g_atomic_int_set(&p->closed, 1);
+    atomic_mb_set(&p->closed, true);
     return false;
 }