add file lock and unlock functions

HISTORY

@@ -1,7 +1,8 @@
 
-Version 1.27  2016-04-08
+Version 1.27  2016-04-09
   * add function fd_set_cloexec
   * php-fastcommon.spec.in support PHP 7
+  * add file lock and unlock functions
 
 Version 1.26  2016-03-16
   * add logger parameter: compress_log_days_before

src/logger.c

@@ -110,32 +110,11 @@ int log_init_ex(LogContext *pContext)
 	return 0;
 }
 
-static int do_lock_file(int fd, int cmd)
-{
-    struct flock lock;
-
-    memset(&lock, 0, sizeof(lock));
-    lock.l_type = cmd;
-    lock.l_whence = SEEK_SET;
-    if (fcntl(fd, F_SETLKW, &lock) != 0)
-    {
-        fprintf(stderr, "call fcntl fail, "
-                "errno: %d, error info: %s\n",
-                errno, STRERROR(errno));
-        return errno != 0 ? errno : ENOMEM;
-    }
-
-    return 0;
-}
-
-#define log_file_lock(fd) do_lock_file(fd, F_WRLCK)
-#define log_file_unlock(fd) do_lock_file(fd, F_UNLCK)
-
 static int log_print_header(LogContext *pContext)
 {
     int result;
 
-    if ((result=log_file_lock(pContext->log_fd)) != 0)
+    if ((result=file_write_lock(pContext->log_fd)) != 0)
     {
         return result;
     }
@@ -144,7 +123,7 @@ static int log_print_header(LogContext *pContext)
     if (pContext->current_size < 0)
     {
         result = errno != 0 ? errno : EACCES;
-        log_file_unlock(pContext->log_fd);
+        file_unlock(pContext->log_fd);
 
         fprintf(stderr, "lseek file \"%s\" fail, " \
                 "errno: %d, error info: %s\n", \
@@ -155,7 +134,7 @@ static int log_print_header(LogContext *pContext)
     {
         pContext->print_header_callback(pContext);
     }
-    log_file_unlock(pContext->log_fd);
+    file_unlock(pContext->log_fd);
 
     return 0;
 }

src/shared_func.c

@@ -2299,3 +2299,40 @@ bool is_power2(const int64_t n)
 	return i == n;
 }
 
+static inline int do_lock_file(int fd, int cmd)
+{
+    struct flock lock;
+    int result;
+
+    memset(&lock, 0, sizeof(lock));
+    lock.l_type = cmd;
+    lock.l_whence = SEEK_SET;
+    do
+    {
+        if ((result=fcntl(fd, F_SETLKW, &lock)) != 0)
+        {
+            result = errno != 0 ? errno : ENOMEM;
+            fprintf(stderr, "call fcntl fail, "
+                   "errno: %d, error info: %s\n",
+                   result, STRERROR(result));
+        }
+    } while (result == EINTR);
+
+    return result;
+}
+
+int file_read_lock(int fd)
+{
+    return do_lock_file(fd, F_RDLCK);
+}
+
+int file_write_lock(int fd)
+{
+    return do_lock_file(fd, F_WRLCK);
+}
+
+int file_unlock(int fd)
+{
+    return do_lock_file(fd, F_UNLCK);
+}
+

src/shared_func.h

@@ -552,6 +552,27 @@ int64_t get_current_time_us();
 */
 bool is_power2(const int64_t n);
 
+/** set file read lock
+ *  parameters:
+ *  	fd: the file descriptor to lock
+ *  return: error no, 0 for success, != 0 fail
+*/
+int file_read_lock(int fd);
+
+/** set file write lock
+ *  parameters:
+ *  	fd: the file descriptor to lock
+ *  return: error no, 0 for success, != 0 fail
+*/
+int file_write_lock(int fd);
+
+/** file unlock
+ *  parameters:
+ *  	fd: the file descriptor to unlock
+ *  return: error no, 0 for success, != 0 fail
+*/
+int file_unlock(int fd);
+
 #ifdef __cplusplus
 }
 #endif