!1478 gstrace start时候，校验下数据库进程是否存在

Merge pull request !1478 from zhangxubo/bug3

src/include/gstrace/gstrace_infra_int.h

@@ -94,6 +94,7 @@ typedef enum trace_msg_code {
     TRACE_SEQ_ERR,
     TRACE_VERSION_ERR,
     TRACE_CONFIG_SIZE_ERR,
+    TRACE_PROCESS_NOT_EXIST,
     TRACE_MSG_MAX,
 } trace_msg_code;
 

src/lib/gstrace/common/gstrace_infra.cpp

@@ -368,6 +368,31 @@ static void detachTraceBufferIfDisabled()
     pTrcCxt->pTrcCfg->bEnabled = false;
 }
 
+static bool checkProcess(int port)
+{
+    int ret;
+    bool procexist = false;
+    char checkcmd[MAX_PATH_LEN] = {0};
+    char buf[MAX_PATH_LEN];
+    FILE* fp = NULL;
+
+    ret = snprintf_s(checkcmd, MAX_PATH_LEN, MAX_PATH_LEN - 1, "lsof -i:%d", port);
+    securec_check_ss_c(ret, "\0", "\0");
+
+    fp = popen(checkcmd, "r");
+    if (fp == NULL) {
+        printf("popen failed. could not query database process.\n");
+        return procexist;
+    } 
+    while (fgets(buf, sizeof(buf), fp) != NULL) {
+        procexist = true;
+        break;
+    }
+    pclose(fp);
+
+    return procexist;
+}
+
 void gstrace_destory(int code, void *arg)
 {
     trace_context* pTrcCxt = getTraceContext();
@@ -549,6 +574,11 @@ trace_msg_code gstrace_start(int key, const char* mask, uint64_t bufferSize, con
         return TRACE_ALREADY_START;
     }
 
+    /* check if database process exist. */
+    if (!checkProcess(key)) {
+        return TRACE_PROCESS_NOT_EXIST;
+    }
+
     /* set the mask if it's passed in */
     if (mask != NULL) {
         trace_mask st_mask = {0};

src/lib/gstrace/tool/gstrace_tool.cpp

@@ -1468,6 +1468,7 @@ trace_msg_t trace_message[] = {
     {TRACE_SEQ_ERR, "Trace sequence check failed."},
     {TRACE_VERSION_ERR, "trace version not match."},
     {TRACE_CONFIG_SIZE_ERR, "invalid config size in trace file."},
+    {TRACE_PROCESS_NOT_EXIST, "The database process is not exist."},
     {TRACE_MSG_MAX, "Failed!"},
 };