[osal]: Add syslog on linux

Change-Id: I484ed12194e2e772326018e7cb1503ab761b2e71
Signed-off-by: Herman Chen <herman.chen@rock-chips.com>

osal/CMakeLists.txt

@@ -46,7 +46,7 @@ add_library(osal STATIC
     linux/os_allocator.c
     linux/os_mem.c
     linux/os_env.c
-    linux/os_log.c
+    linux/os_log.cpp
     windows/os_allocator.c
     windows/os_mem.c
     windows/os_env.c

osal/linux/os_log.cpp

@@ -17,22 +17,47 @@
 #if defined(__gnu_linux__)
 #include <stdio.h>
 #include <stdarg.h>
+#include <syslog.h>
+
 #include "os_log.h"
 
 #define LINE_SZ 1024
 
+class SyslogWrapper
+{
+private:
+    // avoid any unwanted function
+    SyslogWrapper(const SyslogWrapper &);
+    SyslogWrapper &operator=(const SyslogWrapper &);
+public:
+    SyslogWrapper();
+    ~SyslogWrapper();
+};
+
+static SyslogWrapper syslog_wrapper;
+
+SyslogWrapper::SyslogWrapper()
+{
+    openlog("mpp", LOG_PID | LOG_CONS | LOG_PERROR, LOG_USER);
+}
+
+SyslogWrapper::~SyslogWrapper()
+{
+    closelog();
+}
+
 void os_log(const char* tag, const char* msg, va_list list)
 {
     char line[LINE_SZ] = {0};
     snprintf(line, sizeof(line), "%s: %s", tag, msg);
-    vfprintf(stdout, line, list);
+    vsyslog(LOG_INFO, line, list);
 }
 
 void os_err(const char* tag, const char* msg, va_list list)
 {
     char line[LINE_SZ] = {0};
     snprintf(line, sizeof(line), "%s: %s", tag, msg);
-    vfprintf(stderr, line, list);
+    vsyslog(LOG_ERR, line, list);
 }
 
 #endif