[PULL 23/26] monitor: Use LOCK_GUARD macros

[Dr. David Alan Gilbert (git)]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Use the lock guard macros in monitor/misc.c - saves
a lot of unlocks in error paths, and the occasional goto.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200922095741.101911-1-dgilbert@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 monitor/misc.c | 44 ++++++++++++++------------------------------
 1 file changed, 14 insertions(+), 30 deletions(-)

diff --git a/monitor/misc.c b/monitor/misc.c
index 262f2bd951..6e0da0cb96 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -141,13 +141,13 @@ char *qmp_human_monitor_command(const char *command_line, 
bool has_cpu_index,
     handle_hmp_command(&hmp, command_line);
     cur_mon = old_mon;
 
-    qemu_mutex_lock(&hmp.common.mon_lock);
-    if (qstring_get_length(hmp.common.outbuf) > 0) {
-        output = g_strdup(qstring_get_str(hmp.common.outbuf));
-    } else {
-        output = g_strdup("");
+    WITH_QEMU_LOCK_GUARD(&hmp.common.mon_lock) {
+        if (qstring_get_length(hmp.common.outbuf) > 0) {
+            output = g_strdup(qstring_get_str(hmp.common.outbuf));
+        } else {
+            output = g_strdup("");
+        }
     }
-    qemu_mutex_unlock(&hmp.common.mon_lock);
 
 out:
     monitor_data_destroy(&hmp.common);
@@ -1248,7 +1248,7 @@ void qmp_getfd(const char *fdname, Error **errp)
         return;
     }
 
-    qemu_mutex_lock(&cur_mon->mon_lock);
+    QEMU_LOCK_GUARD(&cur_mon->mon_lock);
     QLIST_FOREACH(monfd, &cur_mon->fds, next) {
         if (strcmp(monfd->name, fdname) != 0) {
             continue;
@@ -1256,7 +1256,6 @@ void qmp_getfd(const char *fdname, Error **errp)
 
         tmp_fd = monfd->fd;
         monfd->fd = fd;
-        qemu_mutex_unlock(&cur_mon->mon_lock);
         /* Make sure close() is outside critical section */
         close(tmp_fd);
         return;
@@ -1267,7 +1266,6 @@ void qmp_getfd(const char *fdname, Error **errp)
     monfd->fd = fd;
 
     QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);
-    qemu_mutex_unlock(&cur_mon->mon_lock);
 }
 
 void qmp_closefd(const char *fdname, Error **errp)
@@ -1299,7 +1297,7 @@ int monitor_get_fd(Monitor *mon, const char *fdname, 
Error **errp)
 {
     mon_fd_t *monfd;
 
-    qemu_mutex_lock(&mon->mon_lock);
+    QEMU_LOCK_GUARD(&mon->mon_lock);
     QLIST_FOREACH(monfd, &mon->fds, next) {
         int fd;
 
@@ -1313,12 +1311,10 @@ int monitor_get_fd(Monitor *mon, const char *fdname, 
Error **errp)
         QLIST_REMOVE(monfd, next);
         g_free(monfd->name);
         g_free(monfd);
-        qemu_mutex_unlock(&mon->mon_lock);
 
         return fd;
     }
 
-    qemu_mutex_unlock(&mon->mon_lock);
     error_setg(errp, "File descriptor named '%s' has not been found", fdname);
     return -1;
 }
@@ -1350,11 +1346,10 @@ void monitor_fdsets_cleanup(void)
     MonFdset *mon_fdset;
     MonFdset *mon_fdset_next;
 
-    qemu_mutex_lock(&mon_fdsets_lock);
+    QEMU_LOCK_GUARD(&mon_fdsets_lock);
     QLIST_FOREACH_SAFE(mon_fdset, &mon_fdsets, next, mon_fdset_next) {
         monitor_fdset_cleanup(mon_fdset);
     }
-    qemu_mutex_unlock(&mon_fdsets_lock);
 }
 
 AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, bool has_opaque,
@@ -1389,7 +1384,7 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t 
fd, Error **errp)
     MonFdsetFd *mon_fdset_fd;
     char fd_str[60];
 
-    qemu_mutex_lock(&mon_fdsets_lock);
+    QEMU_LOCK_GUARD(&mon_fdsets_lock);
     QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
         if (mon_fdset->id != fdset_id) {
             continue;
@@ -1409,12 +1404,10 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, 
int64_t fd, Error **errp)
             goto error;
         }
         monitor_fdset_cleanup(mon_fdset);
-        qemu_mutex_unlock(&mon_fdsets_lock);
         return;
     }
 
 error:
-    qemu_mutex_unlock(&mon_fdsets_lock);
     if (has_fd) {
         snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64 ", fd:%" PRId64,
                  fdset_id, fd);
@@ -1430,7 +1423,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp)
     MonFdsetFd *mon_fdset_fd;
     FdsetInfoList *fdset_list = NULL;
 
-    qemu_mutex_lock(&mon_fdsets_lock);
+    QEMU_LOCK_GUARD(&mon_fdsets_lock);
     QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
         FdsetInfoList *fdset_info = g_malloc0(sizeof(*fdset_info));
         FdsetFdInfoList *fdsetfd_list = NULL;
@@ -1460,7 +1453,6 @@ FdsetInfoList *qmp_query_fdsets(Error **errp)
         fdset_info->next = fdset_list;
         fdset_list = fdset_info;
     }
-    qemu_mutex_unlock(&mon_fdsets_lock);
 
     return fdset_list;
 }
@@ -1554,7 +1546,7 @@ int monitor_fdset_dup_fd_add(int64_t fdset_id, int flags)
 #else
     MonFdset *mon_fdset;
 
-    qemu_mutex_lock(&mon_fdsets_lock);
+    QEMU_LOCK_GUARD(&mon_fdsets_lock);
     QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
         MonFdsetFd *mon_fdset_fd;
         MonFdsetFd *mon_fdset_fd_dup;
@@ -1569,7 +1561,6 @@ int monitor_fdset_dup_fd_add(int64_t fdset_id, int flags)
         QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) {
             mon_fd_flags = fcntl(mon_fdset_fd->fd, F_GETFL);
             if (mon_fd_flags == -1) {
-                qemu_mutex_unlock(&mon_fdsets_lock);
                 return -1;
             }
 
@@ -1580,25 +1571,21 @@ int monitor_fdset_dup_fd_add(int64_t fdset_id, int 
flags)
         }
 
         if (fd == -1) {
-            qemu_mutex_unlock(&mon_fdsets_lock);
             errno = EACCES;
             return -1;
         }
 
         dup_fd = qemu_dup_flags(fd, flags);
         if (dup_fd == -1) {
-            qemu_mutex_unlock(&mon_fdsets_lock);
             return -1;
         }
 
         mon_fdset_fd_dup = g_malloc0(sizeof(*mon_fdset_fd_dup));
         mon_fdset_fd_dup->fd = dup_fd;
         QLIST_INSERT_HEAD(&mon_fdset->dup_fds, mon_fdset_fd_dup, next);
-        qemu_mutex_unlock(&mon_fdsets_lock);
         return dup_fd;
     }
 
-    qemu_mutex_unlock(&mon_fdsets_lock);
     errno = ENOENT;
     return -1;
 #endif
@@ -1609,7 +1596,7 @@ static int64_t monitor_fdset_dup_fd_find_remove(int 
dup_fd, bool remove)
     MonFdset *mon_fdset;
     MonFdsetFd *mon_fdset_fd_dup;
 
-    qemu_mutex_lock(&mon_fdsets_lock);
+    QEMU_LOCK_GUARD(&mon_fdsets_lock);
     QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
         QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) {
             if (mon_fdset_fd_dup->fd == dup_fd) {
@@ -1619,17 +1606,14 @@ static int64_t monitor_fdset_dup_fd_find_remove(int 
dup_fd, bool remove)
                     if (QLIST_EMPTY(&mon_fdset->dup_fds)) {
                         monitor_fdset_cleanup(mon_fdset);
                     }
-                    goto err;
+                    return -1;
                 } else {
-                    qemu_mutex_unlock(&mon_fdsets_lock);
                     return mon_fdset->id;
                 }
             }
         }
     }
 
-err:
-    qemu_mutex_unlock(&mon_fdsets_lock);
     return -1;
 }
 
-- 
2.26.2