Patchwork [V2,04/10] oslib-win32: add lock for time functions

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Submitter Wayne Xia
Date Jan. 7, 2013, 7:28 a.m.
Message ID <1357543689-11415-6-git-send-email-xiawenc@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/209874/
State New
Headers show

Comments

Wayne Xia - Jan. 7, 2013, 7:28 a.m.
This patch adding lock for calling gmtime() and localtime()
on windows. If no other lib linked into qemu would call those
two function itself, then they are thread safe now on windows.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 oslib-win32.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

Patch

diff --git a/oslib-win32.c b/oslib-win32.c
index e7e283e..344e3dd 100644
--- a/oslib-win32.c
+++ b/oslib-win32.c
@@ -74,27 +74,35 @@  void qemu_vfree(void *ptr)
     VirtualFree(ptr, 0, MEM_RELEASE);
 }
 
-/* FIXME: add proper locking */
+/* WARN: if other lib call gmtime() itself, then it is not thread safe. */
 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 {
+    static GStaticMutex lock = G_STATIC_MUTEX_INIT;
+
+    g_static_mutex_lock(&lock);
     struct tm *p = gmtime(timep);
     memset(result, 0, sizeof(*result));
     if (p) {
         *result = *p;
         p = result;
     }
+    g_static_mutex_unlock(&lock);
     return p;
 }
 
-/* FIXME: add proper locking */
+/* WARN: if other lib call localtime() itself, then it is not thread safe. */
 struct tm *localtime_r(const time_t *timep, struct tm *result)
 {
+    static GStaticMutex lock = G_STATIC_MUTEX_INIT;
+
+    g_static_mutex_lock(&lock);
     struct tm *p = localtime(timep);
     memset(result, 0, sizeof(*result));
     if (p) {
         *result = *p;
         p = result;
     }
+    g_static_mutex_unlock(&lock);
     return p;
 }