Threads of a process share

Answer: both heap and global variables

Explanation: Threads created within the same process share the process-wide address space. That means the heap and global/static variables are common to all threads and any thread can read or modify data in those regions.

Commonly shared resources include:

• Heap memory

• Global/static variables

• Code/text segment and other process-wide mappings (e.g., memory-mapped files)

• Open file descriptors and other kernel resources associated with the process

Per-thread private resources (not shared):

• Each thread's stack

• CPU context (registers, including the program counter)

• Thread-local storage (TLS)

Practical note: Because the heap and globals are shared, concurrent access must be synchronized (for example, using mutexes) to avoid race conditions.