[Qemu-devel] [PULL 20/34] throttle: Use throttle_config_init() to initialize ThrottleConfig

[Kevin Wolf <kwolf@redhat.com>]

From: Alberto Garcia <berto@igalia.com>

We can currently initialize ThrottleConfig by zeroing all its fields,
but this will change with the new fields to define the length of the
burst periods.

This patch introduces a new throttle_config_init() function and uses it
to replace all memset() calls that initialize ThrottleConfig directly.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 blockdev.c              |  4 ++--
 include/qemu/throttle.h |  2 ++
 tests/test-throttle.c   | 28 +++++++++++++++++-----------
 util/throttle.c         | 10 ++++++++++
 4 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 73babeb..e01486e 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -387,7 +387,7 @@ static void extract_common_blockdev_options(QemuOpts *opts, int *bdrv_flags,
     }
 
     if (throttle_cfg) {
-        memset(throttle_cfg, 0, sizeof(*throttle_cfg));
+        throttle_config_init(throttle_cfg);
         throttle_cfg->buckets[THROTTLE_BPS_TOTAL].avg =
             qemu_opt_get_number(opts, "throttling.bps-total", 0);
         throttle_cfg->buckets[THROTTLE_BPS_READ].avg  =
@@ -2611,7 +2611,7 @@ void qmp_block_set_io_throttle(const char *device, int64_t bps, int64_t bps_rd,
         goto out;
     }
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     cfg.buckets[THROTTLE_BPS_TOTAL].avg = bps;
     cfg.buckets[THROTTLE_BPS_READ].avg  = bps_rd;
     cfg.buckets[THROTTLE_BPS_WRITE].avg = bps_wr;
diff --git a/include/qemu/throttle.h b/include/qemu/throttle.h
index aec0785..8ec8951 100644
--- a/include/qemu/throttle.h
+++ b/include/qemu/throttle.h
@@ -114,6 +114,8 @@ void throttle_config(ThrottleState *ts,
 
 void throttle_get_config(ThrottleState *ts, ThrottleConfig *cfg);
 
+void throttle_config_init(ThrottleConfig *cfg);
+
 /* usage */
 bool throttle_schedule_timer(ThrottleState *ts,
                              ThrottleTimers *tt,
diff --git a/tests/test-throttle.c b/tests/test-throttle.c
index a0c17ac..34f1f9e 100644
--- a/tests/test-throttle.c
+++ b/tests/test-throttle.c
@@ -35,6 +35,9 @@ static bool double_cmp(double x, double y)
 /* tests for single bucket operations */
 static void test_leak_bucket(void)
 {
+    throttle_config_init(&cfg);
+    bkt = cfg.buckets[THROTTLE_BPS_TOTAL];
+
     /* set initial value */
     bkt.avg = 150;
     bkt.max = 15;
@@ -64,6 +67,9 @@ static void test_compute_wait(void)
     int64_t wait;
     int64_t result;
 
+    throttle_config_init(&cfg);
+    bkt = cfg.buckets[THROTTLE_BPS_TOTAL];
+
     /* no operation limit set */
     bkt.avg = 0;
     bkt.max = 15;
@@ -233,17 +239,17 @@ static void test_enabled(void)
 {
     int i;
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     g_assert(!throttle_enabled(&cfg));
 
     for (i = 0; i < BUCKETS_COUNT; i++) {
-        memset(&cfg, 0, sizeof(cfg));
+        throttle_config_init(&cfg);
         set_cfg_value(false, i, 150);
         g_assert(throttle_enabled(&cfg));
     }
 
     for (i = 0; i < BUCKETS_COUNT; i++) {
-        memset(&cfg, 0, sizeof(cfg));
+        throttle_config_init(&cfg);
         set_cfg_value(false, i, -150);
         g_assert(!throttle_enabled(&cfg));
     }
@@ -256,29 +262,29 @@ static void test_conflicts_for_one_set(bool is_max,
                                        int read,
                                        int write)
 {
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     g_assert(throttle_is_valid(&cfg, NULL));
 
     set_cfg_value(is_max, total, 1);
     set_cfg_value(is_max, read,  1);
     g_assert(!throttle_is_valid(&cfg, NULL));
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     set_cfg_value(is_max, total, 1);
     set_cfg_value(is_max, write, 1);
     g_assert(!throttle_is_valid(&cfg, NULL));
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     set_cfg_value(is_max, total, 1);
     set_cfg_value(is_max, read,  1);
     set_cfg_value(is_max, write, 1);
     g_assert(!throttle_is_valid(&cfg, NULL));
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     set_cfg_value(is_max, total, 1);
     g_assert(throttle_is_valid(&cfg, NULL));
 
-    memset(&cfg, 0, sizeof(cfg));
+    throttle_config_init(&cfg);
     set_cfg_value(is_max, read,  1);
     set_cfg_value(is_max, write, 1);
     g_assert(throttle_is_valid(&cfg, NULL));
@@ -315,7 +321,7 @@ static void test_is_valid_for_value(int value, bool should_be_valid)
     int is_max, index;
     for (is_max = 0; is_max < 2; is_max++) {
         for (index = 0; index < BUCKETS_COUNT; index++) {
-            memset(&cfg, 0, sizeof(cfg));
+            throttle_config_init(&cfg);
             set_cfg_value(is_max, index, value);
             g_assert(throttle_is_valid(&cfg, NULL) == should_be_valid);
         }
@@ -337,7 +343,7 @@ static void test_max_is_missing_limit(void)
     int i;
 
     for (i = 0; i < BUCKETS_COUNT; i++) {
-        memset(&cfg, 0, sizeof(cfg));
+        throttle_config_init(&cfg);
         cfg.buckets[i].max = 100;
         cfg.buckets[i].avg = 0;
         g_assert(!throttle_is_valid(&cfg, NULL));
@@ -552,7 +558,7 @@ static void test_groups(void)
     g_assert(bdrv1->throttle_state == bdrv3->throttle_state);
 
     /* Setting the config of a group member affects the whole group */
-    memset(&cfg1, 0, sizeof(cfg1));
+    throttle_config_init(&cfg1);
     cfg1.buckets[THROTTLE_BPS_READ].avg  = 500000;
     cfg1.buckets[THROTTLE_BPS_WRITE].avg = 285000;
     cfg1.buckets[THROTTLE_OPS_READ].avg  = 20000;
diff --git a/util/throttle.c b/util/throttle.c
index f8bf03c..6a01cee 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -171,10 +171,20 @@ void throttle_timers_attach_aio_context(ThrottleTimers *tt,
                                   tt->write_timer_cb, tt->timer_opaque);
 }
 
+/*
+ * Initialize the ThrottleConfig structure to a valid state
+ * @cfg: the config to initialize
+ */
+void throttle_config_init(ThrottleConfig *cfg)
+{
+    memset(cfg, 0, sizeof(*cfg));
+}
+
 /* To be called first on the ThrottleState */
 void throttle_init(ThrottleState *ts)
 {
     memset(ts, 0, sizeof(ThrottleState));
+    throttle_config_init(&ts->cfg);
 }
 
 /* To be called first on the ThrottleTimers */
-- 
1.8.3.1