The out_lock was only protecting out buffers. In the future the monitor
code will start to run in multiple threads. We turn it into a bigger
lock to protect not only the out buffer but also all the rest. We split
this lock until necessary. So far I don't see a reason to complicate
lock usage for monitors.
Since at it, arrange the Monitor struct a bit.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
monitor.c | 39 ++++++++++++++++++---------------------
1 file changed, 18 insertions(+), 21 deletions(-)
diff --git a/monitor.c b/monitor.c
index 39f8ee17ba..c93aa4e22b 100644
--- a/monitor.c
+++ b/monitor.c
@@ -202,20 +202,17 @@ typedef struct {
struct Monitor {
CharBackend chr;
+ /* We can't access guest memory when holding the lock */
+ QemuMutex mon_lock;
int reset_seen;
int flags;
int suspend_cnt; /* Needs to be accessed atomically */
bool skip_flush;
bool use_io_thr;
-
- /* We can't access guest memory when holding the lock */
- QemuMutex out_lock;
QString *outbuf;
guint out_watch;
-
- /* Read under either BQL or out_lock, written with BQL+out_lock. */
+ /* Read under either BQL or mon_lock, written with BQL+mon_lock. */
int mux_out;
-
ReadLineState *rs;
MonitorQMP qmp;
gchar *mon_cpu_path;
@@ -366,14 +363,14 @@ static gboolean monitor_unblocked(GIOChannel *chan,
GIOCondition cond,
{
Monitor *mon = opaque;
- qemu_mutex_lock(&mon->out_lock);
+ qemu_mutex_lock(&mon->mon_lock);
mon->out_watch = 0;
monitor_flush_locked(mon);
- qemu_mutex_unlock(&mon->out_lock);
+ qemu_mutex_unlock(&mon->mon_lock);
return FALSE;
}
-/* Called with mon->out_lock held. */
+/* Called with mon->mon_lock held. */
static void monitor_flush_locked(Monitor *mon)
{
int rc;
@@ -411,9 +408,9 @@ static void monitor_flush_locked(Monitor *mon)
void monitor_flush(Monitor *mon)
{
- qemu_mutex_lock(&mon->out_lock);
+ qemu_mutex_lock(&mon->mon_lock);
monitor_flush_locked(mon);
- qemu_mutex_unlock(&mon->out_lock);
+ qemu_mutex_unlock(&mon->mon_lock);
}
/* flush at every end of line */
@@ -421,7 +418,7 @@ static void monitor_puts(Monitor *mon, const char *str)
{
char c;
- qemu_mutex_lock(&mon->out_lock);
+ qemu_mutex_lock(&mon->mon_lock);
for(;;) {
c = *str++;
if (c == '\0')
@@ -434,7 +431,7 @@ static void monitor_puts(Monitor *mon, const char *str)
monitor_flush_locked(mon);
}
}
- qemu_mutex_unlock(&mon->out_lock);
+ qemu_mutex_unlock(&mon->mon_lock);
}
void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
@@ -728,7 +725,7 @@ static void monitor_data_init(Monitor *mon, bool skip_flush,
bool use_io_thr)
{
memset(mon, 0, sizeof(Monitor));
- qemu_mutex_init(&mon->out_lock);
+ qemu_mutex_init(&mon->mon_lock);
qemu_mutex_init(&mon->qmp.qmp_queue_lock);
mon->outbuf = qstring_new();
/* Use *mon_cmds by default. */
@@ -748,7 +745,7 @@ static void monitor_data_destroy(Monitor *mon)
}
readline_free(mon->rs);
QDECREF(mon->outbuf);
- qemu_mutex_destroy(&mon->out_lock);
+ qemu_mutex_destroy(&mon->mon_lock);
qemu_mutex_destroy(&mon->qmp.qmp_queue_lock);
monitor_qmp_cleanup_req_queue_locked(mon);
monitor_qmp_cleanup_resp_queue_locked(mon);
@@ -780,13 +777,13 @@ 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.out_lock);
+ qemu_mutex_lock(&hmp.mon_lock);
if (qstring_get_length(hmp.outbuf) > 0) {
output = g_strdup(qstring_get_str(hmp.outbuf));
} else {
output = g_strdup("");
}
- qemu_mutex_unlock(&hmp.out_lock);
+ qemu_mutex_unlock(&hmp.mon_lock);
out:
monitor_data_destroy(&hmp);
@@ -4383,9 +4380,9 @@ static void monitor_event(void *opaque, int event)
switch (event) {
case CHR_EVENT_MUX_IN:
- qemu_mutex_lock(&mon->out_lock);
+ qemu_mutex_lock(&mon->mon_lock);
mon->mux_out = 0;
- qemu_mutex_unlock(&mon->out_lock);
+ qemu_mutex_unlock(&mon->mon_lock);
if (mon->reset_seen) {
readline_restart(mon->rs);
monitor_resume(mon);
@@ -4405,9 +4402,9 @@ static void monitor_event(void *opaque, int event)
} else {
atomic_inc(&mon->suspend_cnt);
}
- qemu_mutex_lock(&mon->out_lock);
+ qemu_mutex_lock(&mon->mon_lock);
mon->mux_out = 1;
- qemu_mutex_unlock(&mon->out_lock);
+ qemu_mutex_unlock(&mon->mon_lock);
break;
case CHR_EVENT_OPENED:
--
2.14.3
