Testing and reproduction of concurrency issues

A computer program product for testing a server code in a server concurrently handling multiple client requests, comprising:

• a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a device to cause the device to perform a method comprising:
• creating a job-specific breakpoint in the server code using a library application programming interface, wherein the job-specific breakpoint in the server code is enabled or disabled based on a job identifier dynamically retrieved during execution of the server code using the library application programming interface, the library application programming interface controls the job-specific breakpoint in the server code, the library application programming interface comprises a plurality of readymade functions that execute, in a desired sequence, various synchronous and asynchronous program paths associated with the multiple client requests and are capable of establishing a new server connection with the server and retrieving the job identifier from the server associated with the established new server connection;
• based on the job identifier, pausing an execution of a client job by enabling the job-specific breakpoint in the server code using the library application programming interface;
• based on the job identifier, resuming the execution of the client job by disabling the job-specific breakpoint in the server code using the library application programming interface;
• debugging and reproducing one or more concurrency issues in the server code based on the pausing and resuming of the execution of the client job;
• writing, using the library application programming interface, readable and repeatable reproduction scripts and test cases containing interleaved executions of parallel client requests through various breakpoints;
• and
• performing, using the library application programming interface, one or more of the following error checks:
• determining whether a client job has been created;
• determining whether the client job is currently executing another client request;
• determining whether execution of the another client request is currently paused at a job-specific breakpoint;
• determining whether execution of the client job is currently paused at a specified asynchronous breakpoint;
• determining whether there is no future breakpoint specified for the client job;
• and
• determining whether a future breakpoint has been specified for the client job.