[PULL 05/18] tests: switch MigrateStart struct to be stack allocated

[Dr. David Alan Gilbert (git)]

From: Daniel P. Berrangé <berrange@redhat.com>

There's no compelling reason why the MigrateStart struct needs to be
heap allocated. Using stack allocation and static initializers is
simpler.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220310171821.3724080-8-berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 tests/qtest/migration-test.c | 134 +++++++++++++++--------------------
 1 file changed, 56 insertions(+), 78 deletions(-)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 0870656d82..36e5408702 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -474,28 +474,12 @@ typedef struct {
     bool only_target;
     /* Use dirty ring if true; dirty logging otherwise */
     bool use_dirty_ring;
-    char *opts_source;
-    char *opts_target;
+    const char *opts_source;
+    const char *opts_target;
 } MigrateStart;
 
-static MigrateStart *migrate_start_new(void)
-{
-    MigrateStart *args = g_new0(MigrateStart, 1);
-
-    args->opts_source = g_strdup("");
-    args->opts_target = g_strdup("");
-    return args;
-}
-
-static void migrate_start_destroy(MigrateStart *args)
-{
-    g_free(args->opts_source);
-    g_free(args->opts_target);
-    g_free(args);
-}
-
 static int test_migrate_start(QTestState **from, QTestState **to,
-                              const char *uri, MigrateStart **pargs)
+                              const char *uri, MigrateStart *args)
 {
     g_autofree gchar *arch_source = NULL;
     g_autofree gchar *arch_target = NULL;
@@ -507,15 +491,12 @@ static int test_migrate_start(QTestState **from, 
QTestState **to,
     g_autofree char *shmem_path = NULL;
     const char *arch = qtest_get_arch();
     const char *machine_opts = NULL;
-    MigrateStart *args = *pargs;
     const char *memory_size;
-    int ret = 0;
 
     if (args->use_shmem) {
         if (!g_file_test("/dev/shm", G_FILE_TEST_IS_DIR)) {
             g_test_skip("/dev/shm is not supported");
-            ret = -1;
-            goto out;
+            return -1;
         }
     }
 
@@ -591,7 +572,8 @@ static int test_migrate_start(QTestState **from, QTestState 
**to,
                                  machine_opts ? " -machine " : "",
                                  machine_opts ? machine_opts : "",
                                  memory_size, tmpfs,
-                                 arch_source, shmem_opts, args->opts_source,
+                                 arch_source, shmem_opts,
+                                 args->opts_source ? args->opts_source : "",
                                  ignore_stderr);
     if (!args->only_target) {
         *from = qtest_init(cmd_source);
@@ -609,7 +591,8 @@ static int test_migrate_start(QTestState **from, QTestState 
**to,
                                  machine_opts ? machine_opts : "",
                                  memory_size, tmpfs, uri,
                                  arch_target, shmem_opts,
-                                 args->opts_target, ignore_stderr);
+                                 args->opts_target ? args->opts_target : "",
+                                 ignore_stderr);
     *to = qtest_init(cmd_target);
 
     /*
@@ -620,11 +603,7 @@ static int test_migrate_start(QTestState **from, 
QTestState **to,
         unlink(shmem_path);
     }
 
-out:
-    migrate_start_destroy(args);
-    /* This tells the caller that this structure is gone */
-    *pargs = NULL;
-    return ret;
+    return 0;
 }
 
 static void test_migrate_end(QTestState *from, QTestState *to, bool test_dest)
@@ -668,7 +647,7 @@ static int migrate_postcopy_prepare(QTestState **from_ptr,
     g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
     QTestState *from, *to;
 
-    if (test_migrate_start(&from, &to, uri, &args)) {
+    if (test_migrate_start(&from, &to, uri, args)) {
         return -1;
     }
 
@@ -712,10 +691,10 @@ static void migrate_postcopy_complete(QTestState *from, 
QTestState *to)
 
 static void test_postcopy(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     QTestState *from, *to;
 
-    if (migrate_postcopy_prepare(&from, &to, args)) {
+    if (migrate_postcopy_prepare(&from, &to, &args)) {
         return;
     }
     migrate_postcopy_start(from, to);
@@ -724,13 +703,13 @@ static void test_postcopy(void)
 
 static void test_postcopy_recovery(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .hide_stderr = true,
+    };
     QTestState *from, *to;
     g_autofree char *uri = NULL;
 
-    args->hide_stderr = true;
-
-    if (migrate_postcopy_prepare(&from, &to, args)) {
+    if (migrate_postcopy_prepare(&from, &to, &args)) {
         return;
     }
 
@@ -786,11 +765,11 @@ static void test_postcopy_recovery(void)
 
 static void test_baddest(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .hide_stderr = true
+    };
     QTestState *from, *to;
 
-    args->hide_stderr = true;
-
     if (test_migrate_start(&from, &to, "tcp:127.0.0.1:0", &args)) {
         return;
     }
@@ -802,11 +781,11 @@ static void test_baddest(void)
 static void test_precopy_unix_common(bool dirty_ring)
 {
     g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .use_dirty_ring = dirty_ring,
+    };
     QTestState *from, *to;
 
-    args->use_dirty_ring = dirty_ring;
-
     if (test_migrate_start(&from, &to, uri, &args)) {
         return;
     }
@@ -892,7 +871,7 @@ static void test_ignore_shared(void)
 
 static void test_xbzrle(const char *uri)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     QTestState *from, *to;
 
     if (test_migrate_start(&from, &to, uri, &args)) {
@@ -945,7 +924,7 @@ static void test_xbzrle_unix(void)
 
 static void test_precopy_tcp(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     g_autofree char *uri = NULL;
     QTestState *from, *to;
 
@@ -987,7 +966,7 @@ static void test_precopy_tcp(void)
 
 static void test_migrate_fd_proto(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     QTestState *from, *to;
     int ret;
     int pair[2];
@@ -1074,7 +1053,7 @@ static void do_test_validate_uuid(MigrateStart *args, 
bool should_fail)
     g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
     QTestState *from, *to;
 
-    if (test_migrate_start(&from, &to, uri, &args)) {
+    if (test_migrate_start(&from, &to, uri, args)) {
         return;
     }
 
@@ -1103,51 +1082,49 @@ static void do_test_validate_uuid(MigrateStart *args, 
bool should_fail)
 
 static void test_validate_uuid(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .opts_source = "-uuid 11111111-1111-1111-1111-111111111111",
+        .opts_target = "-uuid 11111111-1111-1111-1111-111111111111",
+    };
 
-    g_free(args->opts_source);
-    g_free(args->opts_target);
-    args->opts_source = g_strdup("-uuid 11111111-1111-1111-1111-111111111111");
-    args->opts_target = g_strdup("-uuid 11111111-1111-1111-1111-111111111111");
-    do_test_validate_uuid(args, false);
+    do_test_validate_uuid(&args, false);
 }
 
 static void test_validate_uuid_error(void)
 {
-    MigrateStart *args = migrate_start_new();
-
-    g_free(args->opts_source);
-    g_free(args->opts_target);
-    args->opts_source = g_strdup("-uuid 11111111-1111-1111-1111-111111111111");
-    args->opts_target = g_strdup("-uuid 22222222-2222-2222-2222-222222222222");
-    args->hide_stderr = true;
-    do_test_validate_uuid(args, true);
+    MigrateStart args = {
+        .opts_source = "-uuid 11111111-1111-1111-1111-111111111111",
+        .opts_target = "-uuid 22222222-2222-2222-2222-222222222222",
+        .hide_stderr = true,
+    };
+
+    do_test_validate_uuid(&args, true);
 }
 
 static void test_validate_uuid_src_not_set(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .opts_target = "-uuid 22222222-2222-2222-2222-222222222222",
+        .hide_stderr = true,
+    };
 
-    g_free(args->opts_target);
-    args->opts_target = g_strdup("-uuid 22222222-2222-2222-2222-222222222222");
-    args->hide_stderr = true;
-    do_test_validate_uuid(args, false);
+    do_test_validate_uuid(&args, false);
 }
 
 static void test_validate_uuid_dst_not_set(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .opts_source = "-uuid 11111111-1111-1111-1111-111111111111",
+        .hide_stderr = true,
+    };
 
-    g_free(args->opts_source);
-    args->opts_source = g_strdup("-uuid 11111111-1111-1111-1111-111111111111");
-    args->hide_stderr = true;
-    do_test_validate_uuid(args, false);
+    do_test_validate_uuid(&args, false);
 }
 
 static void test_migrate_auto_converge(void)
 {
     g_autofree char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     QTestState *from, *to;
     int64_t remaining, percentage;
 
@@ -1230,7 +1207,7 @@ static void test_migrate_auto_converge(void)
 
 static void test_multifd_tcp(const char *method)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {};
     QTestState *from, *to;
     QDict *rsp;
     g_autofree char *uri = NULL;
@@ -1314,13 +1291,13 @@ static void test_multifd_tcp_zstd(void)
  */
 static void test_multifd_tcp_cancel(void)
 {
-    MigrateStart *args = migrate_start_new();
+    MigrateStart args = {
+        .hide_stderr = true,
+    };
     QTestState *from, *to, *to2;
     QDict *rsp;
     g_autofree char *uri = NULL;
 
-    args->hide_stderr = true;
-
     if (test_migrate_start(&from, &to, "defer", &args)) {
         return;
     }
@@ -1357,8 +1334,9 @@ static void test_multifd_tcp_cancel(void)
 
     migrate_cancel(from);
 
-    args = migrate_start_new();
-    args->only_target = true;
+    args = (MigrateStart){
+        .only_target = true,
+    };
 
     if (test_migrate_start(&from, &to2, "defer", &args)) {
         return;
-- 
2.35.1