| # Process |
| |
| ## NAME |
| |
| process - Process abstraction |
| |
| ## SYNOPSIS |
| |
| A zircon process is an instance of a program in the traditional |
| sense: a set of instructions which will be executed by one or more |
| threads, along with a collection of resources. |
| |
| ## DESCRIPTION |
| |
| The process object is a container of the following resources: |
| |
| + [Handles](../handles.md) |
| + [Virtual Memory Address Regions](vm_address_region.md) |
| + [Threads](thread.md) |
| |
| In general, it is associated with code which it is executing until it is |
| forcefully terminated or the program exits. |
| |
| Processes are owned by [jobs](job.md) and allow an application that is |
| composed by more than one process to be treated as a single entity, from the |
| perspective of resource and permission limits, as well as lifetime control. |
| |
| ### Lifetime |
| A process is created via `zx_process_create()` and its execution begins with |
| `zx_process_start()`. |
| |
| The process stops execution when: |
| + the last thread is terminated or exits |
| + the process calls ``zx_process_exit()`` |
| + the parent job terminates the process |
| + the parent job is destroyed |
| |
| The call to `zx_process_start()` cannot be issued twice. New threads cannot |
| be added to a process that was started and then its last thread has exited. |
| |
| ## SYSCALLS |
| |
| + [process_create](../syscalls/process_create.md) - create a new process within a job |
| + [process_read_memory](../syscalls/process_read_memory.md) - read from a process's address space |
| + [process_start](../syscalls/process_start.md) - cause a new process to start executing |
| + [process_write_memory](../syscalls/process_write_memory.md) - write to a process's address space |
| + [process_exit](../syscalls/process_exit.md) - exit the current process |
| |
| <br> |
| |
| + [job_create](../syscalls/job_create.md) - create a new job within a parent job |
| |
| <br> |
| |
| + [vmar_map](../syscalls/vmar_map.md) - Map memory into an address space range |
| + [vmar_protect](../syscalls/vmar_protect.md) - Change permissions on an address space range |
| + [vmar_unmap](../syscalls/vmar_unmap.md) - Unmap memory from an address space range |
