diff --git a/trunk/src/protocol/srs_service_log.cpp b/trunk/src/protocol/srs_service_log.cpp
index 5dafb4c05..2b4af2f27 100644
--- a/trunk/src/protocol/srs_service_log.cpp
+++ b/trunk/src/protocol/srs_service_log.cpp
@@ -49,32 +49,50 @@ SrsContextId SrsThreadContext::generate_id()
     return cid.set_value(srs_random_str(8));
 }
 
+static SrsContextId _srs_context_default;
+static int _srs_context_key = -1;
+void _srs_context_destructor(void* arg)
+{
+    SrsContextId* cid = (SrsContextId*)arg;
+    srs_freep(cid);
+}
+
 const SrsContextId& SrsThreadContext::get_id()
 {
-    return cache[srs_thread_self()];
+    if (!srs_thread_self()) {
+        return _srs_context_default;
+    }
+
+    void* cid = srs_thread_getspecific(_srs_context_key);
+    if (!cid) {
+        return _srs_context_default;
+    }
+
+    return *(SrsContextId*)cid;
 }
 
 const SrsContextId& SrsThreadContext::set_id(const SrsContextId& v)
 {
-    srs_thread_t self = srs_thread_self();
-
-    if (cache.find(self) == cache.end()) {
-        cache[self] = v;
+    if (!srs_thread_self()) {
+        _srs_context_default = v;
         return v;
     }
 
-    const SrsContextId& ov = cache[self];
-    cache[self] = v;
-    return ov;
+    SrsContextId* cid = v.copy();
+
+    if (_srs_context_key < 0) {
+        int r0 = srs_key_create(&_srs_context_key, _srs_context_destructor);
+        srs_assert(r0 == 0);
+    }
+
+    int r0 = srs_thread_setspecific(_srs_context_key, cid);
+    srs_assert(r0 == 0);
+
+    return v;
 }
 
 void SrsThreadContext::clear_cid()
 {
-    srs_thread_t self = srs_thread_self();
-    std::map<srs_thread_t, SrsContextId>::iterator it = cache.find(self);
-    if (it != cache.end()) {
-        cache.erase(it);
-    }
 }
 
 impl_SrsContextRestore::impl_SrsContextRestore(SrsContextId cid)
diff --git a/trunk/src/protocol/srs_service_st.cpp b/trunk/src/protocol/srs_service_st.cpp
index 0e2c4f586..743ee049f 100644
--- a/trunk/src/protocol/srs_service_st.cpp
+++ b/trunk/src/protocol/srs_service_st.cpp
@@ -381,6 +381,21 @@ int srs_mutex_unlock(srs_mutex_t mutex)
     return st_mutex_unlock((st_mutex_t)mutex);
 }
 
+int srs_key_create(int *keyp, void (*destructor)(void *))
+{
+    return st_key_create(keyp, destructor);
+}
+
+int srs_thread_setspecific(int key, void *value)
+{
+    return st_thread_setspecific(key, value);
+}
+
+void *srs_thread_getspecific(int key)
+{
+    return st_thread_getspecific(key);
+}
+
 int srs_netfd_fileno(srs_netfd_t stfd)
 {
     return st_netfd_fileno((st_netfd_t)stfd);
diff --git a/trunk/src/protocol/srs_service_st.hpp b/trunk/src/protocol/srs_service_st.hpp
index ed86737d6..4ae72c8bc 100644
--- a/trunk/src/protocol/srs_service_st.hpp
+++ b/trunk/src/protocol/srs_service_st.hpp
@@ -81,6 +81,10 @@ extern int srs_mutex_destroy(srs_mutex_t mutex);
 extern int srs_mutex_lock(srs_mutex_t mutex);
 extern int srs_mutex_unlock(srs_mutex_t mutex);
 
+extern int srs_key_create(int* keyp, void (*destructor)(void*));
+extern int srs_thread_setspecific(int key, void* value);
+extern void* srs_thread_getspecific(int key);
+
 extern int srs_netfd_fileno(srs_netfd_t stfd);
 
 extern int srs_usleep(srs_utime_t usecs);