Contract
Parameter key	Default value	Type
id	null
env_or_context	null
native_object	opt
Parameter kind	Default value	Type
Other unkeyed arguments	opt with ekind of string	wob

Water Contract
<class thread id =null env_or_context=null native_object =opt _part_name_key="id" _other_unkeyed=opt=wob=ekind.string="_add_to_environment" />

Threads allow more than one sequence of instructions to be executing simultaneously. If there are fewer physical processors than active threads, each thread will get a time slice of the processor to run before another thread gets a chance to run. Typically each time slice is on the order of 10 milliseconds, but programs will often yield their time slice early if (for example), they need to wait for disk or network access. This makes thread-based programs ideal for I/O-bound applications, because time spent waiting for a resource can still be used by other threads. The operating system schedules the time slices so the programmer doesn't have explicit control. However, programmers do have some control over threads. A thread can:

be created and started. See method start
wait for a period of time. See method wait_until_time
wait until another thread is done. See method wait_until_done
wait until an expression returns true. See method wait_until_condition
wait until another thread finishes executing some code.
See method do_solo

When instances of the thread class are created, they are cached in the 'of' field of thread in the usual way. This creates the thread but does not run it.

<thread id="myt">  <echo "myt execution with: " thread.<current/>/>  </thread>

thread.of.myt

Example: returns false since we haven't started this thread yet
thread.of.myt.<is_started/>

false

Starts myt and returns immediately, but in parallel, the echo code above is called in the new thread.

thread.of.myt.<start/>

thread.of.myt

thread.of.myt.<is_started/>

true

Example: returns true if the thread has been started and isn't done
thread.of.myt.<is_running/>

false

Example: returns true when the call to echo completes
thread.of.myt.<is_done/>

true

Water threads are implemented on top of Java threads. You can get at the underlying Java thread from a water thread via its 'native_object' field.

thread.of.myt.native_object