first commit

nghttp2/third-party/mruby/mrbgems/mruby-fiber/mrbgem.rake

@@ -0,0 +1,5 @@
+MRuby::Gem::Specification.new('mruby-fiber') do |spec|
+  spec.license = 'MIT'
+  spec.author  = 'mruby developers'
+  spec.summary = 'Fiber class'
+end

nghttp2/third-party/mruby/mrbgems/mruby-fiber/src/fiber.c

@@ -0,0 +1,426 @@
+#include <mruby.h>
+#include <mruby/array.h>
+#include <mruby/class.h>
+#include <mruby/proc.h>
+
+#define fiber_ptr(o) ((struct RFiber*)mrb_ptr(o))
+
+#define FIBER_STACK_INIT_SIZE 64
+#define FIBER_CI_INIT_SIZE 8
+#define CI_ACC_RESUMED -3
+
+/*
+ *  call-seq:
+ *     Fiber.new{...} -> obj
+ *
+ *  Creates a fiber, whose execution is suspend until it is explicitly
+ *  resumed using <code>Fiber#resume</code> method.
+ *  The code running inside the fiber can give up control by calling
+ *  <code>Fiber.yield</code> in which case it yields control back to caller
+ *  (the caller of the <code>Fiber#resume</code>).
+ *
+ *  Upon yielding or termination the Fiber returns the value of the last
+ *  executed expression
+ *
+ *  For instance:
+ *
+ *    fiber = Fiber.new do
+ *      Fiber.yield 1
+ *      2
+ *    end
+ *
+ *    puts fiber.resume
+ *    puts fiber.resume
+ *    puts fiber.resume
+ *
+ *  <em>produces</em>
+ *
+ *    1
+ *    2
+ *    resuming dead fiber (FiberError)
+ *
+ *  The <code>Fiber#resume</code> method accepts an arbitrary number of
+ *  parameters, if it is the first call to <code>resume</code> then they
+ *  will be passed as block arguments. Otherwise they will be the return
+ *  value of the call to <code>Fiber.yield</code>
+ *
+ *  Example:
+ *
+ *    fiber = Fiber.new do |first|
+ *      second = Fiber.yield first + 2
+ *    end
+ *
+ *    puts fiber.resume 10
+ *    puts fiber.resume 14
+ *    puts fiber.resume 18
+ *
+ *  <em>produces</em>
+ *
+ *    12
+ *    14
+ *    resuming dead fiber (FiberError)
+ *
+ */
+static mrb_value
+fiber_init(mrb_state *mrb, mrb_value self)
+{
+  static const struct mrb_context mrb_context_zero = { 0 };
+  struct RFiber *f = fiber_ptr(self);
+  struct mrb_context *c;
+  struct RProc *p;
+  mrb_callinfo *ci;
+  mrb_value blk;
+  size_t slen;
+
+  mrb_get_args(mrb, "&!", &blk);
+
+  if (f->cxt) {
+    mrb_raise(mrb, E_RUNTIME_ERROR, "cannot initialize twice");
+  }
+  p = mrb_proc_ptr(blk);
+  if (MRB_PROC_CFUNC_P(p)) {
+    mrb_raise(mrb, E_FIBER_ERROR, "tried to create Fiber from C defined method");
+  }
+
+  c = (struct mrb_context*)mrb_malloc(mrb, sizeof(struct mrb_context));
+  *c = mrb_context_zero;
+  f->cxt = c;
+
+  /* initialize VM stack */
+  slen = FIBER_STACK_INIT_SIZE;
+  if (p->body.irep->nregs > slen) {
+    slen += p->body.irep->nregs;
+  }
+  c->stbase = (mrb_value *)mrb_malloc(mrb, slen*sizeof(mrb_value));
+  c->stend = c->stbase + slen;
+  c->stack = c->stbase;
+
+#ifdef MRB_NAN_BOXING
+  {
+    mrb_value *p = c->stbase;
+    mrb_value *pend = c->stend;
+
+    while (p < pend) {
+      SET_NIL_VALUE(*p);
+      p++;
+    }
+  }
+#else
+  memset(c->stbase, 0, slen * sizeof(mrb_value));
+#endif
+
+  /* copy receiver from a block */
+  c->stack[0] = mrb->c->stack[0];
+
+  /* initialize callinfo stack */
+  c->cibase = (mrb_callinfo *)mrb_calloc(mrb, FIBER_CI_INIT_SIZE, sizeof(mrb_callinfo));
+  c->ciend = c->cibase + FIBER_CI_INIT_SIZE;
+  c->ci = c->cibase;
+  c->ci->stackent = c->stack;
+
+  /* adjust return callinfo */
+  ci = c->ci;
+  ci->target_class = MRB_PROC_TARGET_CLASS(p);
+  ci->proc = p;
+  mrb_field_write_barrier(mrb, (struct RBasic*)mrb_obj_ptr(self), (struct RBasic*)p);
+  ci->pc = p->body.irep->iseq;
+  ci[1] = ci[0];
+  c->ci++;                      /* push dummy callinfo */
+
+  c->fib = f;
+  c->status = MRB_FIBER_CREATED;
+
+  return self;
+}
+
+static struct mrb_context*
+fiber_check(mrb_state *mrb, mrb_value fib)
+{
+  struct RFiber *f = fiber_ptr(fib);
+
+  mrb_assert(f->tt == MRB_TT_FIBER);
+  if (!f->cxt) {
+    mrb_raise(mrb, E_FIBER_ERROR, "uninitialized Fiber");
+  }
+  return f->cxt;
+}
+
+static mrb_value
+fiber_result(mrb_state *mrb, const mrb_value *a, mrb_int len)
+{
+  if (len == 0) return mrb_nil_value();
+  if (len == 1) return a[0];
+  return mrb_ary_new_from_values(mrb, len, a);
+}
+
+/* mark return from context modifying method */
+#define MARK_CONTEXT_MODIFY(c) (c)->ci->target_class = NULL
+
+static void
+fiber_check_cfunc(mrb_state *mrb, struct mrb_context *c)
+{
+  mrb_callinfo *ci;
+
+  for (ci = c->ci; ci >= c->cibase; ci--) {
+    if (ci->acc < 0) {
+      mrb_raise(mrb, E_FIBER_ERROR, "can't cross C function boundary");
+    }
+  }
+}
+
+static void
+fiber_switch_context(mrb_state *mrb, struct mrb_context *c)
+{
+  if (mrb->c->fib) {
+    mrb_write_barrier(mrb, (struct RBasic*)mrb->c->fib);
+  }
+  c->status = MRB_FIBER_RUNNING;
+  mrb->c = c;
+}
+
+static mrb_value
+fiber_switch(mrb_state *mrb, mrb_value self, mrb_int len, const mrb_value *a, mrb_bool resume, mrb_bool vmexec)
+{
+  struct mrb_context *c = fiber_check(mrb, self);
+  struct mrb_context *old_c = mrb->c;
+  enum mrb_fiber_state status;
+  mrb_value value;
+
+  fiber_check_cfunc(mrb, c);
+  status = c->status;
+  switch (status) {
+  case MRB_FIBER_TRANSFERRED:
+    if (resume) {
+      mrb_raise(mrb, E_FIBER_ERROR, "resuming transferred fiber");
+    }
+    break;
+  case MRB_FIBER_RUNNING:
+  case MRB_FIBER_RESUMED:
+    mrb_raise(mrb, E_FIBER_ERROR, "double resume");
+    break;
+  case MRB_FIBER_TERMINATED:
+    mrb_raise(mrb, E_FIBER_ERROR, "resuming dead fiber");
+    break;
+  default:
+    break;
+  }
+  old_c->status = resume ? MRB_FIBER_RESUMED : MRB_FIBER_TRANSFERRED;
+  c->prev = resume ? mrb->c : (c->prev ? c->prev : mrb->root_c);
+  fiber_switch_context(mrb, c);
+  if (status == MRB_FIBER_CREATED) {
+    mrb_value *b, *e;
+
+    if (!c->ci->proc) {
+      mrb_raise(mrb, E_FIBER_ERROR, "double resume (current)");
+    }
+    mrb_stack_extend(mrb, len+2); /* for receiver and (optional) block */
+    b = c->stack+1;
+    e = b + len;
+    while (b<e) {
+      *b++ = *a++;
+    }
+    c->cibase->argc = (int)len;
+    value = c->stack[0] = MRB_PROC_ENV(c->ci->proc)->stack[0];
+  }
+  else {
+    value = fiber_result(mrb, a, len);
+  }
+
+  if (vmexec) {
+    c->vmexec = TRUE;
+    value = mrb_vm_exec(mrb, c->ci[-1].proc, c->ci->pc);
+    mrb->c = old_c;
+  }
+  else {
+    MARK_CONTEXT_MODIFY(c);
+  }
+  return value;
+}
+
+/*
+ *  call-seq:
+ *     fiber.resume(args, ...) -> obj
+ *
+ *  Resumes the fiber from the point at which the last <code>Fiber.yield</code>
+ *  was called, or starts running it if it is the first call to
+ *  <code>resume</code>. Arguments passed to resume will be the value of
+ *  the <code>Fiber.yield</code> expression or will be passed as block
+ *  parameters to the fiber's block if this is the first <code>resume</code>.
+ *
+ *  Alternatively, when resume is called it evaluates to the arguments passed
+ *  to the next <code>Fiber.yield</code> statement inside the fiber's block
+ *  or to the block value if it runs to completion without any
+ *  <code>Fiber.yield</code>
+ */
+static mrb_value
+fiber_resume(mrb_state *mrb, mrb_value self)
+{
+  mrb_value *a;
+  mrb_int len;
+  mrb_bool vmexec = FALSE;
+
+  mrb_get_args(mrb, "*!", &a, &len);
+  if (mrb->c->ci->acc < 0) {
+    vmexec = TRUE;
+  }
+  return fiber_switch(mrb, self, len, a, TRUE, vmexec);
+}
+
+/* resume thread with given arguments */
+MRB_API mrb_value
+mrb_fiber_resume(mrb_state *mrb, mrb_value fib, mrb_int len, const mrb_value *a)
+{
+  return fiber_switch(mrb, fib, len, a, TRUE, TRUE);
+}
+
+/*
+ *  call-seq:
+ *     fiber.alive? -> true or false
+ *
+ *  Returns true if the fiber can still be resumed. After finishing
+ *  execution of the fiber block this method will always return false.
+ */
+MRB_API mrb_value
+mrb_fiber_alive_p(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_context *c = fiber_check(mrb, self);
+  return mrb_bool_value(c->status != MRB_FIBER_TERMINATED);
+}
+#define fiber_alive_p mrb_fiber_alive_p
+
+static mrb_value
+fiber_eq(mrb_state *mrb, mrb_value self)
+{
+  mrb_value other = mrb_get_arg1(mrb);
+
+  if (!mrb_fiber_p(other)) {
+    return mrb_false_value();
+  }
+  return mrb_bool_value(fiber_ptr(self) == fiber_ptr(other));
+}
+
+/*
+ *  call-seq:
+ *     fiber.transfer(args, ...) -> obj
+ *
+ *  Transfers control to receiver fiber of the method call.
+ *  Unlike <code>resume</code> the receiver wouldn't be pushed to call
+ * stack of fibers. Instead it will switch to the call stack of
+ * transferring fiber.
+ *  When resuming a fiber that was transferred to another fiber it would
+ * cause double resume error. Though when the fiber is re-transferred
+ * and <code>Fiber.yield</code> is called, the fiber would be resumable.
+ */
+static mrb_value
+fiber_transfer(mrb_state *mrb, mrb_value self)
+{
+  struct mrb_context *c = fiber_check(mrb, self);
+  mrb_value* a;
+  mrb_int len;
+
+  fiber_check_cfunc(mrb, mrb->c);
+  mrb_get_args(mrb, "*!", &a, &len);
+
+  if (c == mrb->root_c) {
+    mrb->c->status = MRB_FIBER_TRANSFERRED;
+    fiber_switch_context(mrb, c);
+    MARK_CONTEXT_MODIFY(c);
+    return fiber_result(mrb, a, len);
+  }
+
+  if (c == mrb->c) {
+    return fiber_result(mrb, a, len);
+  }
+
+  return fiber_switch(mrb, self, len, a, FALSE, FALSE);
+}
+
+/* yield values to the caller fiber */
+/* mrb_fiber_yield() must be called as `return mrb_fiber_yield(...)` */
+MRB_API mrb_value
+mrb_fiber_yield(mrb_state *mrb, mrb_int len, const mrb_value *a)
+{
+  struct mrb_context *c = mrb->c;
+
+  if (!c->prev) {
+    mrb_raise(mrb, E_FIBER_ERROR, "can't yield from root fiber");
+  }
+
+  fiber_check_cfunc(mrb, c);
+  c->prev->status = MRB_FIBER_RUNNING;
+  c->status = MRB_FIBER_SUSPENDED;
+  fiber_switch_context(mrb, c->prev);
+  c->prev = NULL;
+  if (c->vmexec) {
+    c->vmexec = FALSE;
+    mrb->c->ci->acc = CI_ACC_RESUMED;
+  }
+  MARK_CONTEXT_MODIFY(mrb->c);
+  return fiber_result(mrb, a, len);
+}
+
+/*
+ *  call-seq:
+ *     Fiber.yield(args, ...) -> obj
+ *
+ *  Yields control back to the context that resumed the fiber, passing
+ *  along any arguments that were passed to it. The fiber will resume
+ *  processing at this point when <code>resume</code> is called next.
+ *  Any arguments passed to the next <code>resume</code> will be the
+ *
+ *  mruby limitation: Fiber resume/yield cannot cross C function boundary.
+ *  thus you cannot yield from #initialize which is called by mrb_funcall().
+ */
+static mrb_value
+fiber_yield(mrb_state *mrb, mrb_value self)
+{
+  mrb_value *a;
+  mrb_int len;
+
+  mrb_get_args(mrb, "*!", &a, &len);
+  return mrb_fiber_yield(mrb, len, a);
+}
+
+/*
+ *  call-seq:
+ *     Fiber.current() -> fiber
+ *
+ *  Returns the current fiber. If you are not running in the context of
+ *  a fiber this method will return the root fiber.
+ */
+static mrb_value
+fiber_current(mrb_state *mrb, mrb_value self)
+{
+  if (!mrb->c->fib) {
+    struct RFiber *f = (struct RFiber*)mrb_obj_alloc(mrb, MRB_TT_FIBER, mrb_class_ptr(self));
+
+    f->cxt = mrb->c;
+    mrb->c->fib = f;
+  }
+  return mrb_obj_value(mrb->c->fib);
+}
+
+void
+mrb_mruby_fiber_gem_init(mrb_state* mrb)
+{
+  struct RClass *c;
+
+  c = mrb_define_class(mrb, "Fiber", mrb->object_class);
+  MRB_SET_INSTANCE_TT(c, MRB_TT_FIBER);
+
+  mrb_define_method(mrb, c, "initialize", fiber_init,    MRB_ARGS_NONE()|MRB_ARGS_BLOCK());
+  mrb_define_method(mrb, c, "resume",     fiber_resume,  MRB_ARGS_ANY());
+  mrb_define_method(mrb, c, "transfer",   fiber_transfer, MRB_ARGS_ANY());
+  mrb_define_method(mrb, c, "alive?",     fiber_alive_p, MRB_ARGS_NONE());
+  mrb_define_method(mrb, c, "==",         fiber_eq,      MRB_ARGS_REQ(1));
+
+  mrb_define_class_method(mrb, c, "yield", fiber_yield, MRB_ARGS_ANY());
+  mrb_define_class_method(mrb, c, "current", fiber_current, MRB_ARGS_NONE());
+
+  mrb_define_class(mrb, "FiberError", mrb->eStandardError_class);
+}
+
+void
+mrb_mruby_fiber_gem_final(mrb_state* mrb)
+{
+}

nghttp2/third-party/mruby/mrbgems/mruby-fiber/test/fiber.rb

@@ -0,0 +1,208 @@
+assert('Fiber.new') do
+  f = Fiber.new{}
+  assert_kind_of Fiber, f
+end
+
+assert('Fiber#resume') do
+  f = Fiber.new{|x| x }
+  assert_equal 2, f.resume(2)
+end
+
+assert('Fiber#transfer') do
+  f2 = nil
+  f1 = Fiber.new do |v|
+    Fiber.yield v
+    f2.transfer
+  end
+  f2 = Fiber.new do
+    f1.transfer(1)
+    f1.transfer(1)
+    Fiber.yield 2
+  end
+  assert_equal 1, f2.resume
+  assert_raise(FiberError) { f2.resume }
+  assert_equal 2, f2.transfer
+  assert_raise(FiberError) { f1.resume }
+  f1.transfer
+  f2.resume
+  assert_false f1.alive?
+  assert_false f2.alive?
+end
+
+assert('Fiber#alive?') do
+  f = Fiber.new{ Fiber.yield }
+  f.resume
+  assert_true f.alive?
+  f.resume
+  assert_false f.alive?
+end
+
+assert('Fiber#==') do
+  root = Fiber.current
+  assert_equal root, root
+  assert_equal root, Fiber.current
+  assert_false root != Fiber.current
+  f = Fiber.new {
+    assert_false root == Fiber.current
+  }
+  f.resume
+  assert_false f == root
+  assert_true f != root
+end
+
+assert('Fiber.yield') do
+  f = Fiber.new{|x| Fiber.yield x }
+  assert_equal 3, f.resume(3)
+  assert_true f.alive?
+end
+
+assert('FiberError') do
+  assert_equal StandardError, FiberError.superclass
+end
+
+assert('Fiber iteration') do
+  f1 = Fiber.new{
+    [1,2,3].each{|x| Fiber.yield(x)}
+  }
+  f2 = Fiber.new{
+    [9,8,7].each{|x| Fiber.yield(x)}
+  }
+  a = []
+  3.times {
+    a << f1.resume
+    a << f2.resume
+  }
+  assert_equal [1,9,2,8,3,7], a
+end
+
+assert('Fiber with splat in the block argument list') {
+  assert_equal([1], Fiber.new{|*x|x}.resume(1))
+}
+
+assert('Fiber raises on resume when dead') do
+  assert_raise(FiberError) do
+    f = Fiber.new{}
+    f.resume
+    assert_false f.alive?
+    f.resume
+  end
+end
+
+assert('Yield raises when called on root fiber') do
+  assert_raise(FiberError) { Fiber.yield }
+end
+
+assert('Double resume of Fiber') do
+  f1 = Fiber.new {}
+  f2 = Fiber.new {
+    f1.resume
+    assert_raise(FiberError) { f2.resume }
+    Fiber.yield 0
+  }
+  assert_equal 0, f2.resume
+  f2.resume
+  assert_false f1.alive?
+  assert_false f2.alive?
+end
+
+assert('Recursive resume of Fiber') do
+  f1, f2 = nil, nil
+  f1 = Fiber.new { assert_raise(FiberError) { f2.resume } }
+  f2 = Fiber.new {
+    f1.resume
+    Fiber.yield 0
+  }
+  f3 = Fiber.new {
+    f2.resume
+  }
+  assert_equal 0, f3.resume
+  f2.resume
+  assert_false f1.alive?
+  assert_false f2.alive?
+  assert_false f3.alive?
+end
+
+assert('Root fiber resume') do
+  root = Fiber.current
+  assert_raise(FiberError) { root.resume }
+  f = Fiber.new {
+    assert_raise(FiberError) { root.resume }
+  }
+  f.resume
+  assert_false f.alive?
+end
+
+assert('Fiber without block') do
+  assert_raise(ArgumentError) { Fiber.new }
+end
+
+
+assert('Transfer to self.') do
+  result = []
+  f = Fiber.new { result << :start; f.transfer; result << :end  }
+  f.transfer
+  assert_equal [:start, :end], result
+
+  result = []
+  f = Fiber.new { result << :start; f.transfer; result << :end  }
+  f.resume
+  assert_equal [:start, :end], result
+end
+
+assert('Resume transferred fiber') do
+  f = Fiber.new {
+    assert_raise(FiberError) { f.resume }
+  }
+  f.transfer
+end
+
+assert('Root fiber transfer.') do
+  result = nil
+  root = Fiber.current
+  f = Fiber.new {
+    result = :ok
+    root.transfer
+  }
+  f.resume
+  assert_true f.alive?
+  assert_equal :ok, result
+end
+
+assert('Break nested fiber with root fiber transfer') do
+  root = Fiber.current
+
+  result = nil
+  f2 = nil
+  f1 = Fiber.new {
+    Fiber.yield f2.resume
+    result = :f1
+  }
+  f2 = Fiber.new {
+    result = :to_root
+    root.transfer :from_f2
+    result = :f2
+  }
+  assert_equal :from_f2, f1.resume
+  assert_equal :to_root, result
+  assert_equal :f2, f2.transfer
+  assert_equal :f2, result
+  assert_false f2.alive?
+  assert_equal :f1, f1.resume
+  assert_equal :f1, result
+  assert_false f1.alive?
+end
+
+assert('CRuby Fiber#transfer test.') do
+  ary = []
+  f2 = nil
+  f1 = Fiber.new{
+    ary << f2.transfer(:foo)
+    :ok
+  }
+  f2 = Fiber.new{
+    ary << f1.transfer(:baz)
+    :ng
+  }
+  assert_equal :ok, f1.transfer
+  assert_equal [:baz], ary
+end