[Qemu-devel] [PATCH 2/2] oslib-win32: add lock for localtime_r()

[Wenchao Xia]

  Also switch calling of localtime() to localtime_r() in qemu code.

Signed-off-by: Wenchao Xia <xiaw...@linux.vnet.ibm.com>
---
 block.c       |   10 ----------
 block/vvfat.c |   14 +++++---------
 hw/omap1.c    |    2 +-
 oslib-win32.c |    4 +++-
 savevm.c      |    4 ++--
 vl.c          |    9 +++------
 6 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/block.c b/block.c
index 4e28c55..60873ea 100644
--- a/block.c
+++ b/block.c
@@ -3338,11 +3338,7 @@ char *get_human_readable_size(char *buf, int buf_size, 
int64_t size)
 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
 {
     char buf1[128], date_buf[128], clock_buf[128];
-#ifdef _WIN32
-    struct tm *ptm;
-#else
     struct tm tm;
-#endif
     time_t ti;
     int64_t secs;
 
@@ -3352,15 +3348,9 @@ char *bdrv_snapshot_dump(char *buf, int buf_size, 
QEMUSnapshotInfo *sn)
                  "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
     } else {
         ti = sn->date_sec;
-#ifdef _WIN32
-        ptm = localtime(&ti);
-        strftime(date_buf, sizeof(date_buf),
-                 "%Y-%m-%d %H:%M:%S", ptm);
-#else
         localtime_r(&ti, &tm);
         strftime(date_buf, sizeof(date_buf),
                  "%Y-%m-%d %H:%M:%S", &tm);
-#endif
         secs = sn->vm_clock_nsec / 1000000000;
         snprintf(clock_buf, sizeof(clock_buf),
                  "%02d:%02d:%02d.%03d",
diff --git a/block/vvfat.c b/block/vvfat.c
index 83706ce..4a56fc6 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -527,15 +527,11 @@ static inline uint8_t fat_chksum(const direntry_t* entry)
 }
 
 /* if return_time==0, this returns the fat_date, else the fat_time */
-static uint16_t fat_datetime(time_t time,int return_time) {
-    struct tm* t;
-#ifdef _WIN32
-    t=localtime(&time); /* this is not thread safe */
-#else
-    struct tm t1;
-    t = &t1;
-    localtime_r(&time,t);
-#endif
+static uint16_t fat_datetime(time_t time, int return_time)
+{
+    struct tm *t, t1;
+
+    t = localtime_r(&time, &t1);
     if(return_time)
        return cpu_to_le16((t->tm_sec/2)|(t->tm_min<<5)|(t->tm_hour<<11));
     return cpu_to_le16((t->tm_mday)|((t->tm_mon+1)<<5)|((t->tm_year-80)<<9));
diff --git a/hw/omap1.c b/hw/omap1.c
index 8536e96..e85f2e2 100644
--- a/hw/omap1.c
+++ b/hw/omap1.c
@@ -2830,7 +2830,7 @@ static void omap_rtc_tick(void *opaque)
         s->round = 0;
     }
 
-    memcpy(&s->current_tm, localtime(&s->ti), sizeof(s->current_tm));
+    localtime_r(&s->ti, &s->current_tm);
 
     if ((s->interrupts & 0x08) && s->ti == s->alarm_ti) {
         s->status |= 0x40;
diff --git a/oslib-win32.c b/oslib-win32.c
index 74e0c52..d96d053 100644
--- a/oslib-win32.c
+++ b/oslib-win32.c
@@ -90,15 +90,17 @@ struct tm *gmtime_r(const time_t *timep, struct tm *result)
     return p;
 }
 
-/* FIXME: add proper locking */
+/* FIXME: add proper locking in MinGW */
 struct tm *localtime_r(const time_t *timep, struct tm *result)
 {
+    g_static_mutex_lock(&time_lock);
     struct tm *p = localtime(timep);
     memset(result, 0, sizeof(*result));
     if (p) {
         *result = *p;
         p = result;
     }
+    g_static_mutex_unlock(&time_lock);
     return p;
 }
 
diff --git a/savevm.c b/savevm.c
index 529d60e..ce18762 100644
--- a/savevm.c
+++ b/savevm.c
@@ -2095,7 +2095,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     uint64_t vm_state_size;
 #ifdef _WIN32
     struct _timeb tb;
-    struct tm *ptm;
+    struct tm *ptm, tm;
 #else
     struct timeval tv;
     struct tm tm;
@@ -2151,7 +2151,7 @@ void do_savevm(Monitor *mon, const QDict *qdict)
     } else {
 #ifdef _WIN32
         time_t t = tb.time;
-        ptm = localtime(&t);
+        ptm = localtime_r(&t, &tm);
         strftime(sn->name, sizeof(sn->name), "vm-%Y%m%d%H%M%S", ptm);
 #else
         /* cast below needed for OpenBSD where tv_sec is still 'long' */
diff --git a/vl.c b/vl.c
index 8d7864c..e5da31c 100644
--- a/vl.c
+++ b/vl.c
@@ -448,21 +448,18 @@ StatusInfo *qmp_query_status(Error **errp)
 void qemu_get_timedate(struct tm *tm, int offset)
 {
     time_t ti;
-    struct tm *ret;
 
     time(&ti);
     ti += offset;
     if (rtc_date_offset == -1) {
         if (rtc_utc)
-            ret = gmtime_r(&ti, tm);
+            gmtime_r(&ti, tm);
         else
-            ret = localtime(&ti);
+            localtime_r(&ti, tm);
     } else {
         ti -= rtc_date_offset;
-        ret = gmtime_r(&ti, tm);
+        gmtime_r(&ti, tm);
     }
-
-    memcpy(tm, ret, sizeof(struct tm));
 }
 
 int qemu_timedate_diff(struct tm *tm)
-- 
1.7.1