ThreadGroup provides a means of keeping track of a number of threads as a group.
A given Thread object can only belong to one ThreadGroup at a time; adding a thread to a new group will remove it from any previous group.
Newly created threads belong to the same group as the thread from which they were created.
The default ThreadGroup created when Ruby starts; all Threads belong to it by default.
Adds the given thread
to this group, removing it from any
other group to which it may have previously been a member.
puts "Initial group is #{ThreadGroup::Default.list}" tg = ThreadGroup.new t1 = Thread.new { sleep } t2 = Thread.new { sleep } puts "t1 is #{t1}" puts "t2 is #{t2}" tg.add(t1) puts "Initial group now #{ThreadGroup::Default.list}" puts "tg group now #{tg.list}"
This will produce:
Initial group is #<Thread:0x401bdf4c> t1 is #<Thread:0x401b3c90> t2 is #<Thread:0x401b3c18> Initial group now #<Thread:0x401b3c18>#<Thread:0x401bdf4c> tg group now #<Thread:0x401b3c90>
static VALUE thgroup_add(VALUE group, VALUE thread) { rb_thread_t *target_th = rb_thread_ptr(thread); struct thgroup *data; if (OBJ_FROZEN(group)) { rb_raise(rb_eThreadError, "can't move to the frozen thread group"); } TypedData_Get_Struct(group, struct thgroup, &thgroup_data_type, data); if (data->enclosed) { rb_raise(rb_eThreadError, "can't move to the enclosed thread group"); } if (!target_th->thgroup) { return Qnil; } if (OBJ_FROZEN(target_th->thgroup)) { rb_raise(rb_eThreadError, "can't move from the frozen thread group"); } TypedData_Get_Struct(target_th->thgroup, struct thgroup, &thgroup_data_type, data); if (data->enclosed) { rb_raise(rb_eThreadError, "can't move from the enclosed thread group"); } target_th->thgroup = group; return group; }
Prevents threads from being added to or removed from the receiving ThreadGroup.
New threads can still be started in an enclosed ThreadGroup.
ThreadGroup::Default.enclose #=> #<ThreadGroup:0x4029d914> thr = Thread.new { Thread.stop } #=> #<Thread:0x402a7210 sleep> tg = ThreadGroup.new #=> #<ThreadGroup:0x402752d4> tg.add thr #=> ThreadError: can't move from the enclosed thread group
static VALUE thgroup_enclose(VALUE group) { struct thgroup *data; TypedData_Get_Struct(group, struct thgroup, &thgroup_data_type, data); data->enclosed = 1; return group; }
Returns true
if the thgrp
is enclosed. See also
#enclose.
static VALUE thgroup_enclosed_p(VALUE group) { struct thgroup *data; TypedData_Get_Struct(group, struct thgroup, &thgroup_data_type, data); if (data->enclosed) return Qtrue; return Qfalse; }
Returns an array of all existing Thread objects that belong to this group.
ThreadGroup::Default.list #=> [#<Thread:0x401bdf4c run>]
static VALUE thgroup_list(VALUE group) { VALUE ary = rb_ary_new(); rb_vm_t *vm = GET_THREAD()->vm; rb_thread_t *th = 0; list_for_each(&vm->living_threads, th, vmlt_node) { if (th->thgroup == group) { rb_ary_push(ary, th->self); } } return ary; }