USE OF SINGLE CONTROL FLOW TO SUPPORT MULTIPLE NETWORK CONNECTIONS FOR SERVER LOAD TESTING

A load testing system for testing a web site or other type of server system uses a thread architecture that reduces the computing resources needed to generate a desired load. The load testing system runs several virtual users on one or more clients to simulate user interactions with the web site. Each virtual user is executed as a virtual user thread under a process on a client computer. Each virtual user thread itself establishes and supports multiple connections to the web site; therefore, an additional thread need not be created for each connection. For each connection, the virtual user thread performs a sequence of functions in an asynchronous mode to establish and support the connection. If a function cannot complete without blocking, it immediately returns a RESOURCE UNAVAILABLE error code. If a function returns a RESOURCE UNAVAILABLE code, the calling thread switches execution to another task. After the condition causing the RESOURCE UNAVAILABLE error code has been resolved, the thread can switch back to executing the interrupted task. In this manner, the single thread is able to support multiple simultaneous connections.