refine comment

src/brpc/details/controller_private_accessor.h

@@ -128,6 +128,8 @@ public:
     std::string& protocol_param() { return _cntl->protocol_param(); }
     const std::string& protocol_param() const { return _cntl->protocol_param(); }
 
+    // Note: This function can only be called in server side. The deadline of client
+    // side is properly set in the RPC sending path.
     void set_deadline_us(int64_t deadline_us) { _cntl->_deadline_us = deadline_us; }
 
 private:

src/brpc/policy/http_rpc_protocol.cpp

@@ -1191,7 +1191,7 @@ void EndRunningCallMethodInPool(
     ::google::protobuf::Message* response,
     ::google::protobuf::Closure* done);
 
-static int64_t ConvertGrpcTimeoutToMS(int64_t timeout_value, const char timeout_unit) {
+static int64_t ConvertGrpcTimeoutToUS(int64_t timeout_value, const char timeout_unit) {
     switch (timeout_unit) {
         case 'H':
             timeout_value *= (3600 * 1000000L);
@@ -1451,12 +1451,23 @@ void ProcessHttpRequest(InputMessageBase *msg) {
                     const std::string* grpc_timeout = req_header.GetHeader(common->GRPC_TIMEOUT);
                     if (grpc_timeout && !grpc_timeout->empty()) {
                         const char timeout_unit = grpc_timeout->back();
-                        // If no digits were found, strtol returns zero as timeout value
-                        int64_t timeout_value_ms =
-                            ConvertGrpcTimeoutToMS((int64_t)strtol(grpc_timeout->data(), NULL, 10), timeout_unit);
-                        if (timeout_value_ms >= 0) {
-                            accessor.set_deadline_us(
-                                    butil::gettimeofday_us() + timeout_value_ms);
+                        char* endptr = NULL;
+                        int64_t timeout_value = (int64_t)strtol(grpc_timeout->data(), &endptr, 10);
+                        // Only the format that the digit number is equal to (timeout header size - 1) is valid.
+                        // Otherwise the format is not valid and the is treated as no deadline.
+                        // For example:
+                        //      1H, 2993S, 82m is valid.
+                        //      30A is also valid, but the following ConvertGrpcTimeoutToUS would return -1 since 'A'
+                        //          is not a valid time unit.
+                        //      123ASH is not vaid since the digit number is 3, while the size is 6.
+                        //      HHH is not valid since the dight number is 0, while the size is 3.
+                        if (endptr - grpc_timeout->data() == grpc_timeout->size() - 1) {
+                            int64_t timeout_value_us =
+                                ConvertGrpcTimeoutToUS( timeout_unit);
+                            if (timeout_value_us >= 0) {
+                                accessor.set_deadline_us(
+                                        butil::gettimeofday_us() + timeout_value_us);
+                            }
                         }
                     }
                 }