Producer Consumer problem in C Linux

Multiple producers, one consumer. Shared buffer of fixed size. Producers must deposit the items (items are randomly generated) in ascending order into the buffer and the consumer must read the items and print them in the same order as they are deposited. Required: mutex and condition variables. The program_template is the overall structure of the code with the already implemneted functions that must be used. The program file is my incomplete work that does not work and that I need help with (especially the sorting part). The assignment pdf file is the description of what the program should do.