Thread

Returns the thread debug level. Available only if compiled with THREAD_DEBUG=-1.

 
               static VALUE
rb_thread_s_debug(VALUE _)
{
    return INT2NUM(rb_thread_debug_enabled);
}
            

Sets the thread debug level. Available only if compiled with THREAD_DEBUG=-1.

 
               static VALUE
rb_thread_s_debug_set(VALUE self, VALUE val)
{
    rb_thread_debug_enabled = RTEST(val) ? NUM2INT(val) : 0;
    return val;
}
            

Returns the status of the global “abort on exception'' condition.

The default is false.

When set to true, if any thread is aborted by an exception, the raised exception will be re-raised in the main thread.

Can also be specified by the global $DEBUG flag or command line option -d.

See also ::abort_on_exception=.

There is also an instance level method to set this for a specific thread, see abort_on_exception.

 
               static VALUE
rb_thread_s_abort_exc(VALUE _)
{
    return RBOOL(GET_THREAD()->vm->thread_abort_on_exception);
}
            

When set to true, if any thread is aborted by an exception, the raised exception will be re-raised in the main thread. Returns the new state.

Thread.abort_on_exception = true
t1 = Thread.new do
  puts  "In new thread"
  raise "Exception from thread"
end
sleep(1)
puts "not reached"

This will produce:

In new thread
prog.rb:4: Exception from thread (RuntimeError)
 from prog.rb:2:in `initialize'
 from prog.rb:2:in `new'
 from prog.rb:2

See also ::abort_on_exception.

There is also an instance level method to set this for a specific thread, see abort_on_exception=.

 
               static VALUE
rb_thread_s_abort_exc_set(VALUE self, VALUE val)
{
    GET_THREAD()->vm->thread_abort_on_exception = RTEST(val);
    return val;
}
            

Returns the currently executing thread.

Thread.current   #=> #<Thread:0x401bdf4c run>

 
               static VALUE
thread_s_current(VALUE klass)
{
    return rb_thread_current();
}
            

Terminates the currently running thread and schedules another thread to be run.

If this thread is already marked to be killed, ::exit returns the Thread.

If this is the main thread, or the last thread, exit the process.

 
               static VALUE
rb_thread_exit(VALUE _)
{
    rb_thread_t *th = GET_THREAD();
    return rb_thread_kill(th->self);
}
            

Basically the same as ::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass's initialize method.

 
               static VALUE
thread_start(VALUE klass, VALUE args)
{
    struct thread_create_params params = {
        .type = thread_invoke_type_proc,
        .args = args,
        .proc = rb_block_proc(),
    };
    return thread_create_core(rb_thread_alloc(klass), &params);
}
            

Changes asynchronous interrupt timing.

interrupt means asynchronous event and corresponding procedure by Thread#raise, Thread#kill, signal trap (not supported yet) and main thread termination (if main thread terminates, then all other thread will be killed).

The given hash has pairs like ExceptionClass => :TimingSymbol. Where the ExceptionClass is the interrupt handled by the given block. The TimingSymbol can be one of the following symbols:

:immediate

Invoke interrupts immediately.

:on_blocking

Invoke interrupts while BlockingOperation.

:never

Never invoke all interrupts.

BlockingOperation means that the operation will block the calling thread, such as read and write. On CRuby implementation, BlockingOperation is any operation executed without GVL.

Masked asynchronous interrupts are delayed until they are enabled. This method is similar to sigprocmask(3).

NOTE¶ ↑

Asynchronous interrupts are difficult to use.

If you need to communicate between threads, please consider to use another way such as Queue.

Or use them with deep understanding about this method.

Usage¶ ↑

In this example, we can guard from Thread#raise exceptions.

Using the :never TimingSymbol the RuntimeError exception will always be ignored in the first block of the main thread. In the second ::handle_interrupt block we can purposefully handle RuntimeError exceptions.

th = Thread.new do
  Thread.handle_interrupt(RuntimeError => :never) {
    begin
      # You can write resource allocation code safely.
      Thread.handle_interrupt(RuntimeError => :immediate) {
        # ...
      }
    ensure
      # You can write resource deallocation code safely.
    end
  }
end
Thread.pass
# ...
th.raise "stop"

While we are ignoring the RuntimeError exception, it's safe to write our resource allocation code. Then, the ensure block is where we can safely deallocate your resources.

Guarding from Timeout::Error¶ ↑

In the next example, we will guard from the Timeout::Error exception. This will help prevent from leaking resources when Timeout::Error exceptions occur during normal ensure clause. For this example we use the help of the standard library Timeout, from lib/timeout.rb

require 'timeout'
Thread.handle_interrupt(Timeout::Error => :never) {
  timeout(10){
    # Timeout::Error doesn't occur here
    Thread.handle_interrupt(Timeout::Error => :on_blocking) {
      # possible to be killed by Timeout::Error
      # while blocking operation
    }
    # Timeout::Error doesn't occur here
  }
}

In the first part of the timeout block, we can rely on Timeout::Error being ignored. Then in the Timeout::Error => :on_blocking block, any operation that will block the calling thread is susceptible to a Timeout::Error exception being raised.

Stack control settings¶ ↑

It's possible to stack multiple levels of ::handle_interrupt blocks in order to control more than one ExceptionClass and TimingSymbol at a time.

Thread.handle_interrupt(FooError => :never) {
  Thread.handle_interrupt(BarError => :never) {
     # FooError and BarError are prohibited.
  }
}

Inheritance with ExceptionClass¶ ↑

All exceptions inherited from the ExceptionClass parameter will be considered.

Thread.handle_interrupt(Exception => :never) {
  # all exceptions inherited from Exception are prohibited.
}

For handling all interrupts, use Object and not Exception as the ExceptionClass, as kill/terminate interrupts are not handled by Exception.

 
               static VALUE
rb_thread_s_handle_interrupt(VALUE self, VALUE mask_arg)
{
    VALUE mask;
    rb_execution_context_t * volatile ec = GET_EC();
    rb_thread_t * volatile th = rb_ec_thread_ptr(ec);
    volatile VALUE r = Qnil;
    enum ruby_tag_type state;

    if (!rb_block_given_p()) {
        rb_raise(rb_eArgError, "block is needed.");
    }

    mask = 0;
    mask_arg = rb_to_hash_type(mask_arg);
    rb_hash_foreach(mask_arg, handle_interrupt_arg_check_i, (VALUE)&mask);
    if (!mask) {
        return rb_yield(Qnil);
    }
    OBJ_FREEZE_RAW(mask);
    rb_ary_push(th->pending_interrupt_mask_stack, mask);
    if (!rb_threadptr_pending_interrupt_empty_p(th)) {
        th->pending_interrupt_queue_checked = 0;
        RUBY_VM_SET_INTERRUPT(th->ec);
    }

    EC_PUSH_TAG(th->ec);
    if ((state = EC_EXEC_TAG()) == TAG_NONE) {
        r = rb_yield(Qnil);
    }
    EC_POP_TAG();

    rb_ary_pop(th->pending_interrupt_mask_stack);
    if (!rb_threadptr_pending_interrupt_empty_p(th)) {
        th->pending_interrupt_queue_checked = 0;
        RUBY_VM_SET_INTERRUPT(th->ec);
    }

    RUBY_VM_CHECK_INTS(th->ec);

    if (state) {
        EC_JUMP_TAG(th->ec, state);
    }

    return r;
}
            

Returns the status of the global “ignore deadlock'' condition. The default is false, so that deadlock conditions are not ignored.

See also ::ignore_deadlock=.

 
               static VALUE
rb_thread_s_ignore_deadlock(VALUE _)
{
    return RBOOL(GET_THREAD()->vm->thread_ignore_deadlock);
}
            

Returns the new state. When set to true, the VM will not check for deadlock conditions. It is only useful to set this if your application can break a deadlock condition via some other means, such as a signal.

Thread.ignore_deadlock = true
queue = Thread::Queue.new

trap(:SIGUSR1){queue.push "Received signal"}

# raises fatal error unless ignoring deadlock
puts queue.pop

See also ::ignore_deadlock.

 
               static VALUE
rb_thread_s_ignore_deadlock_set(VALUE self, VALUE val)
{
    GET_THREAD()->vm->thread_ignore_deadlock = RTEST(val);
    return val;
}
            

Causes the given thread to exit, see also Thread::exit.

count = 0
a = Thread.new { loop { count += 1 } }
sleep(0.1)       #=> 0
Thread.kill(a)   #=> #<Thread:0x401b3d30 dead>
count            #=> 93947
a.alive?         #=> false

 
               static VALUE
rb_thread_s_kill(VALUE obj, VALUE th)
{
    return rb_thread_kill(th);
}
            

Returns an array of Thread objects for all threads that are either runnable or stopped.

Thread.new { sleep(200) }
Thread.new { 1000000.times {|i| i*i } }
Thread.new { Thread.stop }
Thread.list.each {|t| p t}

This will produce:

#<Thread:0x401b3e84 sleep>
#<Thread:0x401b3f38 run>
#<Thread:0x401b3fb0 sleep>
#<Thread:0x401bdf4c run>

 
               static VALUE
thread_list(VALUE _)
{
    return rb_thread_list();
}
            

Returns the main thread.

 
               static VALUE
rb_thread_s_main(VALUE klass)
{
    return rb_thread_main();
}
            

Creates a new thread executing the given block.

Any args given to ::new will be passed to the block:

arr = []
a, b, c = 1, 2, 3
Thread.new(a,b,c) { |d,e,f| arr << d << e << f }.join
arr #=> [1, 2, 3]

A ThreadError exception is raised if ::new is called without a block.

If you're going to subclass Thread, be sure to call super in your initialize method, otherwise a ThreadError will be raised.

 
               static VALUE
thread_s_new(int argc, VALUE *argv, VALUE klass)
{
    rb_thread_t *th;
    VALUE thread = rb_thread_alloc(klass);

    if (GET_RACTOR()->threads.main->status == THREAD_KILLED) {
        rb_raise(rb_eThreadError, "can't alloc thread");
    }

    rb_obj_call_init_kw(thread, argc, argv, RB_PASS_CALLED_KEYWORDS);
    th = rb_thread_ptr(thread);
    if (!threadptr_initialized(th)) {
        rb_raise(rb_eThreadError, "uninitialized thread - check `%"PRIsVALUE"#initialize'",
                 klass);
    }
    return thread;
}
            

Give the thread scheduler a hint to pass execution to another thread. A running thread may or may not switch, it depends on OS and processor.

 
               static VALUE
thread_s_pass(VALUE klass)
{
    rb_thread_schedule();
    return Qnil;
}
            

Returns whether or not the asynchronous queue is empty.

Since Thread::handle_interrupt can be used to defer asynchronous events, this method can be used to determine if there are any deferred events.

If you find this method returns true, then you may finish :never blocks.

For example, the following method processes deferred asynchronous events immediately.

def Thread.kick_interrupt_immediately
  Thread.handle_interrupt(Object => :immediate) {
    Thread.pass
  }
end

If error is given, then check only for error type deferred events.

Usage¶ ↑

th = Thread.new{
  Thread.handle_interrupt(RuntimeError => :on_blocking){
    while true
      ...
      # reach safe point to invoke interrupt
      if Thread.pending_interrupt?
        Thread.handle_interrupt(Object => :immediate){}
      end
      ...
    end
  }
}
...
th.raise # stop thread

This example can also be written as the following, which you should use to avoid asynchronous interrupts.

flag = true
th = Thread.new{
  Thread.handle_interrupt(RuntimeError => :on_blocking){
    while true
      ...
      # reach safe point to invoke interrupt
      break if flag == false
      ...
    end
  }
}
...
flag = false # stop thread

 
               static VALUE
rb_thread_s_pending_interrupt_p(int argc, VALUE *argv, VALUE self)
{
    return rb_thread_pending_interrupt_p(argc, argv, GET_THREAD()->self);
}
            

Returns the status of the global “report on exception'' condition.

The default is true since Ruby 2.5.

All threads created when this flag is true will report a message on $stderr if an exception kills the thread.

Thread.new { 1.times { raise } }

will produce this output on $stderr:

#<Thread:...> terminated with exception (report_on_exception is true):
Traceback (most recent call last):
        2: from -e:1:in `block in <main>'
        1: from -e:1:in `times'

This is done to catch errors in threads early. In some cases, you might not want this output. There are multiple ways to avoid the extra output:

• If the exception is not intended, the best is to fix the cause of the exception so it does not happen anymore.

• If the exception is intended, it might be better to rescue it closer to where it is raised rather then let it kill the Thread.

• If it is guaranteed the Thread will be joined with Thread#join or Thread#value, then it is safe to disable this report with Thread.current.report_on_exception = false when starting the Thread. However, this might handle the exception much later, or not at all if the Thread is never joined due to the parent thread being blocked, etc.

See also ::report_on_exception=.

There is also an instance level method to set this for a specific thread, see report_on_exception=.

 
               static VALUE
rb_thread_s_report_exc(VALUE _)
{
    return RBOOL(GET_THREAD()->vm->thread_report_on_exception);
}
            

Returns the new state. When set to true, all threads created afterwards will inherit the condition and report a message on $stderr if an exception kills a thread:

Thread.report_on_exception = true
t1 = Thread.new do
  puts  "In new thread"
  raise "Exception from thread"
end
sleep(1)
puts "In the main thread"

This will produce:

In new thread
#<Thread:...prog.rb:2> terminated with exception (report_on_exception is true):
Traceback (most recent call last):
prog.rb:4:in `block in <main>': Exception from thread (RuntimeError)
In the main thread

See also ::report_on_exception.

There is also an instance level method to set this for a specific thread, see report_on_exception=.

 
               static VALUE
rb_thread_s_report_exc_set(VALUE self, VALUE val)
{
    GET_THREAD()->vm->thread_report_on_exception = RTEST(val);
    return val;
}
            

Basically the same as ::new. However, if class Thread is subclassed, then calling start in that subclass will not invoke the subclass's initialize method.

 
               static VALUE
thread_start(VALUE klass, VALUE args)
{
    struct thread_create_params params = {
        .type = thread_invoke_type_proc,
        .args = args,
        .proc = rb_block_proc(),
    };
    return thread_create_core(rb_thread_alloc(klass), &params);
}
            

Stops execution of the current thread, putting it into a “sleep'' state, and schedules execution of another thread.

a = Thread.new { print "a"; Thread.stop; print "c" }
sleep 0.1 while a.status!='sleep'
print "b"
a.run
a.join
#=> "abc"

 
               static VALUE
thread_stop(VALUE _)
{
    return rb_thread_stop();
}
            

Attribute Reference—Returns the value of a fiber-local variable (current thread's root fiber if not explicitly inside a Fiber), using either a symbol or a string name. If the specified variable does not exist, returns nil.

[
  Thread.new { Thread.current["name"] = "A" },
  Thread.new { Thread.current[:name]  = "B" },
  Thread.new { Thread.current["name"] = "C" }
].each do |th|
  th.join
  puts "#{th.inspect}: #{th[:name]}"
end

This will produce:

#<Thread:0x00000002a54220 dead>: A
#<Thread:0x00000002a541a8 dead>: B
#<Thread:0x00000002a54130 dead>: C

Thread#[] and Thread#[]= are not thread-local but fiber-local. This confusion did not exist in Ruby 1.8 because fibers are only available since Ruby 1.9. Ruby 1.9 chooses that the methods behaves fiber-local to save following idiom for dynamic scope.

def meth(newvalue)
  begin
    oldvalue = Thread.current[:name]
    Thread.current[:name] = newvalue
    yield
  ensure
    Thread.current[:name] = oldvalue
  end
end

The idiom may not work as dynamic scope if the methods are thread-local and a given block switches fiber.

f = Fiber.new {
  meth(1) {
    Fiber.yield
  }
}
meth(2) {
  f.resume
}
f.resume
p Thread.current[:name]
#=> nil if fiber-local
#=> 2 if thread-local (The value 2 is leaked to outside of meth method.)

For thread-local variables, please see thread_variable_get and thread_variable_set.

 
               static VALUE
rb_thread_aref(VALUE thread, VALUE key)
{
    ID id = rb_check_id(&key);
    if (!id) return Qnil;
    return rb_thread_local_aref(thread, id);
}
            

Attribute Assignment—Sets or creates the value of a fiber-local variable, using either a symbol or a string.

See also Thread#[].

For thread-local variables, please see thread_variable_set and thread_variable_get.

 
               static VALUE
rb_thread_aset(VALUE self, VALUE id, VALUE val)
{
    return rb_thread_local_aset(self, rb_to_id(id), val);
}
            

Returns the status of the thread-local “abort on exception'' condition for this thr.

The default is false.

See also abort_on_exception=.

There is also a class level method to set this for all threads, see ::abort_on_exception.

 
               static VALUE
rb_thread_abort_exc(VALUE thread)
{
    return RBOOL(rb_thread_ptr(thread)->abort_on_exception);
}
            

When set to true, if this thr is aborted by an exception, the raised exception will be re-raised in the main thread.

See also abort_on_exception.

There is also a class level method to set this for all threads, see ::abort_on_exception=.

 
               static VALUE
rb_thread_abort_exc_set(VALUE thread, VALUE val)
{
    rb_thread_ptr(thread)->abort_on_exception = RTEST(val);
    return val;
}
            

Adds proc as a handler for tracing.

See Thread#set_trace_func and Kernel#set_trace_func.

 
               static VALUE
thread_add_trace_func_m(VALUE obj, VALUE trace)
{
    thread_add_trace_func(GET_EC(), rb_thread_ptr(obj), trace);
    return trace;
}
            

Returns true if thr is running or sleeping.

thr = Thread.new { }
thr.join                #=> #<Thread:0x401b3fb0 dead>
Thread.current.alive?   #=> true
thr.alive?              #=> false

See also stop? and status.

 
               static VALUE
rb_thread_alive_p(VALUE thread)
{
    return RBOOL(!thread_finished(rb_thread_ptr(thread)));
}
            

Returns the current backtrace of the target thread.

 
               static VALUE
rb_thread_backtrace_m(int argc, VALUE *argv, VALUE thval)
{
    return rb_vm_thread_backtrace(argc, argv, thval);
}
            

Returns the execution stack for the target thread—an array containing backtrace location objects.

See Thread::Backtrace::Location for more information.

This method behaves similarly to Kernel#caller_locations except it applies to a specific thread.

 
               static VALUE
rb_thread_backtrace_locations_m(int argc, VALUE *argv, VALUE thval)
{
    return rb_vm_thread_backtrace_locations(argc, argv, thval);
}
            

Terminates thr and schedules another thread to be run, returning the terminated Thread. If this is the main thread, or the last thread, exits the process.

 
               VALUE
rb_thread_kill(VALUE thread)
{
    rb_thread_t *th = rb_thread_ptr(thread);

    if (th->to_kill || th->status == THREAD_KILLED) {
        return thread;
    }
    if (th == th->vm->ractor.main_thread) {
        rb_exit(EXIT_SUCCESS);
    }

    thread_debug("rb_thread_kill: %p (%"PRI_THREAD_ID")\n", (void *)th, thread_id_str(th));

    if (th == GET_THREAD()) {
        /* kill myself immediately */
        rb_threadptr_to_kill(th);
    }
    else {
        threadptr_check_pending_interrupt_queue(th);
        rb_threadptr_pending_interrupt_enque(th, eKillSignal);
        rb_threadptr_interrupt(th);
    }
    return thread;
}
            

Returns a fiber-local for the given key. If the key can't be found, there are several options: With no other arguments, it will raise a KeyError exception; if default is given, then that will be returned; if the optional code block is specified, then that will be run and its result returned. See Thread#[] and Hash#fetch.

 
               static VALUE
rb_thread_fetch(int argc, VALUE *argv, VALUE self)
{
    VALUE key, val;
    ID id;
    rb_thread_t *target_th = rb_thread_ptr(self);
    int block_given;

    rb_check_arity(argc, 1, 2);
    key = argv[0];

    block_given = rb_block_given_p();
    if (block_given && argc == 2) {
        rb_warn("block supersedes default value argument");
    }

    id = rb_check_id(&key);

    if (id == recursive_key) {
        return target_th->ec->local_storage_recursive_hash;
    }
    else if (id && target_th->ec->local_storage &&
             rb_id_table_lookup(target_th->ec->local_storage, id, &val)) {
        return val;
    }
    else if (block_given) {
        return rb_yield(key);
    }
    else if (argc == 1) {
        rb_key_err_raise(rb_sprintf("key not found: %+"PRIsVALUE, key), self, key);
    }
    else {
        return argv[1];
    }
}
            

Returns the ThreadGroup which contains the given thread.

Thread.main.group   #=> #<ThreadGroup:0x4029d914>

 
               VALUE
rb_thread_group(VALUE thread)
{
    return rb_thread_ptr(thread)->thgroup;
}
            

The calling thread will suspend execution and run this thr.

Does not return until thr exits or until the given limit seconds have passed.

If the time limit expires, nil will be returned, otherwise thr is returned.

Any threads not joined will be killed when the main program exits.

If thr had previously raised an exception and the ::abort_on_exception or $DEBUG flags are not set, (so the exception has not yet been processed), it will be processed at this time.

a = Thread.new { print "a"; sleep(10); print "b"; print "c" }
x = Thread.new { print "x"; Thread.pass; print "y"; print "z" }
x.join # Let thread x finish, thread a will be killed on exit.
#=> "axyz"

The following example illustrates the limit parameter.

y = Thread.new { 4.times { sleep 0.1; puts 'tick... ' }}
puts "Waiting" until y.join(0.15)

This will produce:

tick...
Waiting
tick...
Waiting
tick...
tick...

 
               static VALUE
thread_join_m(int argc, VALUE *argv, VALUE self)
{
    VALUE timeout = Qnil;
    rb_hrtime_t rel = 0, *limit = 0;

    if (rb_check_arity(argc, 0, 1)) {
        timeout = argv[0];
    }

    // Convert the timeout eagerly, so it's always converted and deterministic
    /*
     * This supports INFINITY and negative values, so we can't use
     * rb_time_interval right now...
     */
    if (NIL_P(timeout)) {
        /* unlimited */
    }
    else if (FIXNUM_P(timeout)) {
        rel = rb_sec2hrtime(NUM2TIMET(timeout));
        limit = &rel;
    }
    else {
        limit = double2hrtime(&rel, rb_num2dbl(timeout));
    }

    return thread_join(rb_thread_ptr(self), timeout, limit);
}
            

Returns true if the given string (or symbol) exists as a fiber-local variable.

me = Thread.current
me[:oliver] = "a"
me.key?(:oliver)    #=> true
me.key?(:stanley)   #=> false

 
               static VALUE
rb_thread_key_p(VALUE self, VALUE key)
{
    VALUE val;
    ID id = rb_check_id(&key);
    struct rb_id_table *local_storage = rb_thread_ptr(self)->ec->local_storage;

    if (!id || local_storage == NULL) {
        return Qfalse;
    }
    return RBOOL(rb_id_table_lookup(local_storage, id, &val));
}
            

Returns an array of the names of the fiber-local variables (as Symbols).

thr = Thread.new do
  Thread.current[:cat] = 'meow'
  Thread.current["dog"] = 'woof'
end
thr.join   #=> #<Thread:0x401b3f10 dead>
thr.keys   #=> [:dog, :cat]

 
               static VALUE
rb_thread_keys(VALUE self)
{
    struct rb_id_table *local_storage = rb_thread_ptr(self)->ec->local_storage;
    VALUE ary = rb_ary_new();

    if (local_storage) {
        rb_id_table_foreach(local_storage, thread_keys_i, (void *)ary);
    }
    return ary;
}
            

Terminates thr and schedules another thread to be run, returning the terminated Thread. If this is the main thread, or the last thread, exits the process.

 
               VALUE
rb_thread_kill(VALUE thread)
{
    rb_thread_t *th = rb_thread_ptr(thread);

    if (th->to_kill || th->status == THREAD_KILLED) {
        return thread;
    }
    if (th == th->vm->ractor.main_thread) {
        rb_exit(EXIT_SUCCESS);
    }

    thread_debug("rb_thread_kill: %p (%"PRI_THREAD_ID")\n", (void *)th, thread_id_str(th));

    if (th == GET_THREAD()) {
        /* kill myself immediately */
        rb_threadptr_to_kill(th);
    }
    else {
        threadptr_check_pending_interrupt_queue(th);
        rb_threadptr_pending_interrupt_enque(th, eKillSignal);
        rb_threadptr_interrupt(th);
    }
    return thread;
}
            

show the name of the thread.

 
               static VALUE
rb_thread_getname(VALUE thread)
{
    return rb_thread_ptr(thread)->name;
}
            

set given name to the ruby thread. On some platform, it may set the name to pthread and/or kernel.

 
               static VALUE
rb_thread_setname(VALUE thread, VALUE name)
{
    rb_thread_t *target_th = rb_thread_ptr(thread);

    if (!NIL_P(name)) {
        rb_encoding *enc;
        StringValueCStr(name);
        enc = rb_enc_get(name);
        if (!rb_enc_asciicompat(enc)) {
            rb_raise(rb_eArgError, "ASCII incompatible encoding (%s)",
                     rb_enc_name(enc));
        }
        name = rb_str_new_frozen(name);
    }
    target_th->name = name;
    if (threadptr_initialized(target_th)) {
        native_set_another_thread_name(target_th->thread_id, name);
    }
    return name;
}
            

Return the native thread ID which is used by the Ruby thread.

The ID depends on the OS. (not POSIX thread ID returned by pthread_self(3))

• On Linux it is TID returned by gettid(2).

• On macOS it is the system-wide unique integral ID of thread returned by pthread_threadid_np(3).

• On FreeBSD it is the unique integral ID of the thread returned by pthread_getthreadid_np(3).

• On Windows it is the thread identifier returned by GetThreadId().

• On other platforms, it raises NotImplementedError.

NOTE: If the thread is not associated yet or already deassociated with a native thread, it returns nil. If the Ruby implementation uses M:N thread model, the ID may change depending on the timing.

 
               static VALUE
rb_thread_native_thread_id(VALUE thread)
{
    rb_thread_t *target_th = rb_thread_ptr(thread);
    if (rb_threadptr_dead(target_th)) return Qnil;
    return native_thread_native_thread_id(target_th);
}
            

Returns whether or not the asynchronous queue is empty for the target thread.

If error is given, then check only for error type deferred events.

See ::pending_interrupt? for more information.

 
               static VALUE
rb_thread_pending_interrupt_p(int argc, VALUE *argv, VALUE target_thread)
{
    rb_thread_t *target_th = rb_thread_ptr(target_thread);

    if (!target_th->pending_interrupt_queue) {
        return Qfalse;
    }
    if (rb_threadptr_pending_interrupt_empty_p(target_th)) {
        return Qfalse;
    }
    if (rb_check_arity(argc, 0, 1)) {
        VALUE err = argv[0];
        if (!rb_obj_is_kind_of(err, rb_cModule)) {
            rb_raise(rb_eTypeError, "class or module required for rescue clause");
        }
        return RBOOL(rb_threadptr_pending_interrupt_include_p(target_th, err));
    }
    else {
        return Qtrue;
    }
}
            

Returns the priority of thr. Default is inherited from the current thread which creating the new thread, or zero for the initial main thread; higher-priority thread will run more frequently than lower-priority threads (but lower-priority threads can also run).

This is just hint for Ruby thread scheduler. It may be ignored on some platform.

Thread.current.priority   #=> 0

 
               static VALUE
rb_thread_priority(VALUE thread)
{
    return INT2NUM(rb_thread_ptr(thread)->priority);
}
            

Sets the priority of thr to integer. Higher-priority threads will run more frequently than lower-priority threads (but lower-priority threads can also run).

This is just hint for Ruby thread scheduler. It may be ignored on some platform.

count1 = count2 = 0
a = Thread.new do
      loop { count1 += 1 }
    end
a.priority = -1

b = Thread.new do
      loop { count2 += 1 }
    end
b.priority = -2
sleep 1   #=> 1
count1    #=> 622504
count2    #=> 5832

 
               static VALUE
rb_thread_priority_set(VALUE thread, VALUE prio)
{
    rb_thread_t *target_th = rb_thread_ptr(thread);
    int priority;

#if USE_NATIVE_THREAD_PRIORITY
    target_th->priority = NUM2INT(prio);
    native_thread_apply_priority(th);
#else
    priority = NUM2INT(prio);
    if (priority > RUBY_THREAD_PRIORITY_MAX) {
        priority = RUBY_THREAD_PRIORITY_MAX;
    }
    else if (priority < RUBY_THREAD_PRIORITY_MIN) {
        priority = RUBY_THREAD_PRIORITY_MIN;
    }
    target_th->priority = (int8_t)priority;
#endif
    return INT2NUM(target_th->priority);
}
            

Raises an exception from the given thread. The caller does not have to be thr. See Kernel#raise for more information.

Thread.abort_on_exception = true
a = Thread.new { sleep(200) }
a.raise("Gotcha")

This will produce:

prog.rb:3: Gotcha (RuntimeError)
 from prog.rb:2:in `initialize'
 from prog.rb:2:in `new'
 from prog.rb:2

 
               static VALUE
thread_raise_m(int argc, VALUE *argv, VALUE self)
{
    rb_thread_t *target_th = rb_thread_ptr(self);
    const rb_thread_t *current_th = GET_THREAD();

    threadptr_check_pending_interrupt_queue(target_th);
    rb_threadptr_raise(target_th, argc, argv);

    /* To perform Thread.current.raise as Kernel.raise */
    if (current_th == target_th) {
        RUBY_VM_CHECK_INTS(target_th->ec);
    }
    return Qnil;
}
            

Returns the status of the thread-local “report on exception'' condition for this thr.

The default value when creating a Thread is the value of the global flag Thread.report_on_exception.

See also report_on_exception=.

There is also a class level method to set this for all new threads, see ::report_on_exception=.

 
               static VALUE
rb_thread_report_exc(VALUE thread)
{
    return RBOOL(rb_thread_ptr(thread)->report_on_exception);
}
            

When set to true, a message is printed on $stderr if an exception kills this thr. See ::report_on_exception for details.

See also report_on_exception.

There is also a class level method to set this for all new threads, see ::report_on_exception=.

 
               static VALUE
rb_thread_report_exc_set(VALUE thread, VALUE val)
{
    rb_thread_ptr(thread)->report_on_exception = RTEST(val);
    return val;
}
            

Wakes up thr, making it eligible for scheduling.

a = Thread.new { puts "a"; Thread.stop; puts "c" }
sleep 0.1 while a.status!='sleep'
puts "Got here"
a.run
a.join

This will produce:

a
Got here
c

See also the instance method wakeup.

 
               VALUE
rb_thread_run(VALUE thread)
{
    rb_thread_wakeup(thread);
    rb_thread_schedule();
    return thread;
}
            

Establishes proc on thr as the handler for tracing, or disables tracing if the parameter is nil.

See Kernel#set_trace_func.

 
               static VALUE
thread_set_trace_func_m(VALUE target_thread, VALUE trace)
{
    rb_execution_context_t *ec = GET_EC();
    rb_thread_t *target_th = rb_thread_ptr(target_thread);

    rb_threadptr_remove_event_hook(ec, target_th, call_trace_func, Qundef);

    if (NIL_P(trace)) {
        return Qnil;
    }
    else {
        thread_add_trace_func(ec, target_th, trace);
        return trace;
    }
}
            

Returns the status of thr.

"sleep"

Returned if this thread is sleeping or waiting on I/O

"run"

When this thread is executing

"aborting"

If this thread is aborting

false

When this thread is terminated normally

nil

If terminated with an exception.

a = Thread.new { raise("die now") }
b = Thread.new { Thread.stop }
c = Thread.new { Thread.exit }
d = Thread.new { sleep }
d.kill                  #=> #<Thread:0x401b3678 aborting>
a.status                #=> nil
b.status                #=> "sleep"
c.status                #=> false
d.status                #=> "aborting"
Thread.current.status   #=> "run"

See also the instance methods alive? and stop?

 
               static VALUE
rb_thread_status(VALUE thread)
{
    rb_thread_t *target_th = rb_thread_ptr(thread);

    if (rb_threadptr_dead(target_th)) {
        if (!NIL_P(target_th->ec->errinfo) &&
            !FIXNUM_P(target_th->ec->errinfo)) {
            return Qnil;
        }
        else {
            return Qfalse;
        }
    }
    else {
        return rb_str_new2(thread_status_name(target_th, FALSE));
    }
}
            

Returns true if thr is dead or sleeping.

a = Thread.new { Thread.stop }
b = Thread.current
a.stop?   #=> true
b.stop?   #=> false

See also alive? and status.

 
               static VALUE
rb_thread_stop_p(VALUE thread)
{
    rb_thread_t *th = rb_thread_ptr(thread);

    if (rb_threadptr_dead(th)) {
        return Qtrue;
    }
    return RBOOL(th->status == THREAD_STOPPED || th->status == THREAD_STOPPED_FOREVER);
}
            

Terminates thr and schedules another thread to be run, returning the terminated Thread. If this is the main thread, or the last thread, exits the process.

 
               VALUE
rb_thread_kill(VALUE thread)
{
    rb_thread_t *th = rb_thread_ptr(thread);

    if (th->to_kill || th->status == THREAD_KILLED) {
        return thread;
    }
    if (th == th->vm->ractor.main_thread) {
        rb_exit(EXIT_SUCCESS);
    }

    thread_debug("rb_thread_kill: %p (%"PRI_THREAD_ID")\n", (void *)th, thread_id_str(th));

    if (th == GET_THREAD()) {
        /* kill myself immediately */
        rb_threadptr_to_kill(th);
    }
    else {
        threadptr_check_pending_interrupt_queue(th);
        rb_threadptr_pending_interrupt_enque(th, eKillSignal);
        rb_threadptr_interrupt(th);
    }
    return thread;
}
            

Returns true if the given string (or symbol) exists as a thread-local variable.

me = Thread.current
me.thread_variable_set(:oliver, "a")
me.thread_variable?(:oliver)    #=> true
me.thread_variable?(:stanley)   #=> false

Note that these are not fiber local variables. Please see Thread#[] and Thread#thread_variable_get for more details.

 
               static VALUE
rb_thread_variable_p(VALUE thread, VALUE key)
{
    VALUE locals;

    if (LIKELY(!THREAD_LOCAL_STORAGE_INITIALISED_P(thread))) {
        return Qfalse;
    }
    locals = rb_thread_local_storage(thread);

    return RBOOL(rb_hash_lookup(locals, rb_to_symbol(key)) != Qnil);
}
            

Returns the value of a thread local variable that has been set. Note that these are different than fiber local values. For fiber local values, please see Thread#[] and Thread#[]=.

Thread local values are carried along with threads, and do not respect fibers. For example:

Thread.new {
  Thread.current.thread_variable_set("foo", "bar") # set a thread local
  Thread.current["foo"] = "bar"                    # set a fiber local

  Fiber.new {
    Fiber.yield [
      Thread.current.thread_variable_get("foo"), # get the thread local
      Thread.current["foo"],                     # get the fiber local
    ]
  }.resume
}.join.value # => ['bar', nil]

The value “bar” is returned for the thread local, where nil is returned for the fiber local. The fiber is executed in the same thread, so the thread local values are available.

 
               static VALUE
rb_thread_variable_get(VALUE thread, VALUE key)
{
    VALUE locals;

    if (LIKELY(!THREAD_LOCAL_STORAGE_INITIALISED_P(thread))) {
        return Qnil;
    }
    locals = rb_thread_local_storage(thread);
    return rb_hash_aref(locals, rb_to_symbol(key));
}
            

Sets a thread local with key to value. Note that these are local to threads, and not to fibers. Please see Thread#thread_variable_get and Thread#[] for more information.

 
               static VALUE
rb_thread_variable_set(VALUE thread, VALUE key, VALUE val)
{
    VALUE locals;

    if (OBJ_FROZEN(thread)) {
        rb_frozen_error_raise(thread, "can't modify frozen thread locals");
    }

    locals = rb_thread_local_storage(thread);
    return rb_hash_aset(locals, rb_to_symbol(key), val);
}
            

Returns an array of the names of the thread-local variables (as Symbols).

thr = Thread.new do
  Thread.current.thread_variable_set(:cat, 'meow')
  Thread.current.thread_variable_set("dog", 'woof')
end
thr.join               #=> #<Thread:0x401b3f10 dead>
thr.thread_variables   #=> [:dog, :cat]

Note that these are not fiber local variables. Please see Thread#[] and Thread#thread_variable_get for more details.

 
               static VALUE
rb_thread_variables(VALUE thread)
{
    VALUE locals;
    VALUE ary;

    ary = rb_ary_new();
    if (LIKELY(!THREAD_LOCAL_STORAGE_INITIALISED_P(thread))) {
        return ary;
    }
    locals = rb_thread_local_storage(thread);
    rb_hash_foreach(locals, keys_i, ary);

    return ary;
}
            

Dump the name, id, and status of thr to a string.

 
               static VALUE
rb_thread_to_s(VALUE thread)
{
    VALUE cname = rb_class_path(rb_obj_class(thread));
    rb_thread_t *target_th = rb_thread_ptr(thread);
    const char *status;
    VALUE str, loc;

    status = thread_status_name(target_th, TRUE);
    str = rb_sprintf("#<%"PRIsVALUE":%p", cname, (void *)thread);
    if (!NIL_P(target_th->name)) {
        rb_str_catf(str, "@%"PRIsVALUE, target_th->name);
    }
    if ((loc = threadptr_invoke_proc_location(target_th)) != Qnil) {
        rb_str_catf(str, " %"PRIsVALUE":%"PRIsVALUE,
                    RARRAY_AREF(loc, 0), RARRAY_AREF(loc, 1));
    }
    rb_str_catf(str, " %s>", status);

    return str;
}
            

Waits for thr to complete, using join, and returns its value or raises the exception which terminated the thread.

a = Thread.new { 2 + 2 }
a.value   #=> 4

b = Thread.new { raise 'something went wrong' }
b.value   #=> RuntimeError: something went wrong

 
               static VALUE
thread_value(VALUE self)
{
    rb_thread_t *th = rb_thread_ptr(self);
    thread_join(th, Qnil, 0);
    return th->value;
}
            

Marks a given thread as eligible for scheduling, however it may still remain blocked on I/O.

Note: This does not invoke the scheduler, see run for more information.

c = Thread.new { Thread.stop; puts "hey!" }
sleep 0.1 while c.status!='sleep'
c.wakeup
c.join
#=> "hey!"

 
               VALUE
rb_thread_wakeup(VALUE thread)
{
    if (!RTEST(rb_thread_wakeup_alive(thread))) {
        rb_raise(rb_eThreadError, "killed thread");
    }
    return thread;
}