diff --git a/HISTORY b/HISTORY
index 9f01486..86e59d5 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,4 +1,7 @@
 
+Version 1.56  2022-01-29
+  * add function fc_gettid
+
 Version 1.55  2022-01-12
   * fastcommon php extension adapt to php 8
   * function fast_mblock_batch_alloc changed
diff --git a/src/shared_func.h b/src/shared_func.h
index a5818c7..272ade3 100644
--- a/src/shared_func.h
+++ b/src/shared_func.h
@@ -19,11 +19,15 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
+#include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include "common_define.h"
+#ifdef OS_LINUX
+#include <sys/syscall.h>
+#endif
 #include "fc_memory.h"
 #include "ini_file_reader.h"
 
@@ -1212,6 +1216,21 @@ static inline int fc_check_realloc_iovec_array(
     return 0;
 }
 
+static inline pid_t fc_gettid()
+{
+#ifdef OS_LINUX
+
+#ifdef SYS_gettid
+    return (pid_t)syscall(SYS_gettid);
+#else
+    return getpid();
+#endif
+
+#else
+    return getpid();
+#endif
+}
+
 #ifdef __cplusplus
 }
 #endif