[PATCH v2 1/9] util/error: Introduce warn_report_once_err()

[Cédric Le Goater]

Depending on the configuration, a passthrough device may produce
recurring DMA mapping errors at runtime and produce a lot of
output. It is useful to report only once.

Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 include/qapi/error.h | 5 +++++
 util/error.c         | 9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/qapi/error.h b/include/qapi/error.h
index 
71f8fb2c50eee9a544992d0c05263c9793956fe1..b6ea274882b9788b64d4bb213c3458d7c674a881
 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -448,6 +448,11 @@ void error_free_or_abort(Error **errp);
  */
 void warn_report_err(Error *err);
 
+/*
+ * Convenience function to call warn_report_err() once.
+ */
+void warn_report_once_err(Error *err);
+
 /*
  * Convenience function to error_report() and free @err.
  * The report includes hints added with error_append_hint().
diff --git a/util/error.c b/util/error.c
index 
e5e247209a9e0796074a9794f5598325f22f8d35..b8a211cccaa609a93091b86316144a0ad0a02662
 100644
--- a/util/error.c
+++ b/util/error.c
@@ -247,6 +247,15 @@ void warn_report_err(Error *err)
     error_free(err);
 }
 
+void warn_report_once_err(Error *err)
+{
+        static bool print_once_;
+        if (!print_once_) {
+            warn_report_err(err);
+            print_once_ = true;
+        }
+}
+
 void error_reportf_err(Error *err, const char *fmt, ...)
 {
     va_list ap;
-- 
2.48.1