Header only file with only two functions that let you easily measure pagefaults inside any given codeblock on linux.
Include the file, if you want the implementation add #define MESAURE_PAGEFAULT_IMPLEMENTATION before #include "measure_pagefault.h"
You don't need a seperate file like example_include.c in the example, but I included it to make it easier for me to debug include
conflicts when developing single header libraries(like forgetting to put the decleration of something on the file etc..), you can simply
put the #define MESAURE_PAGEFAULT_IMPLEMENTATION and #include "measure_pagefault.h" into the same file and it will work properly.
I seperated only becasue it is easier for me to track include errors.
To start the pagefault counter use start_pagefault_counter(); It takes one parameter, flags which can be either MEASURE_HARD_FAULTS
or MEASURE_SOFT_FAULTS or both of them if you or them together. The function returns page_fault_ctx, which is a handle to the current
counter, the variable failed inside page_fault_ctx is set to 1 if there was an error initializing the pagefault counter, the error
can be printed with strerror(errno)(not always, if the flags are not valid errno would not be set). Do not forget to store the errno
before doing any operation that can alter errno!
To end the counter call end_pagefault_counter() passing the previously returned struct page_fault_ctx, the function returns
struct page_fault_result which contains soft_fault_count and hard_fault_count. If you did not specify a flag and read how
many faults occoured from that flag you will not get an accurate result! So if you only pass MEASURE_HARD_FAULTS and try
to read soft_fault_count you will not get an accurate result! Those values will always be set to 0 if you did not specify the flag.
Number of page faults can also be obtained with get_pagefault_counter() function, which does not terminate the counter unlike end_pagefault_counter()
An example usage is inside example.c, which can be compiled with running ./build_debug.sh, which generates example binary which you can run to test the program.
Make sure to #define _GNU_SOURCE before including unistd.h, the library does it but if you include it before and don't set than
syscall will not be avaliable as it is not a POSIX standart, or use a C version that supports gnu like -std=gnu99 etc..