Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk
git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/base/task.cc b/talk/base/task.cc
new file mode 100644
index 0000000..c37797c
--- /dev/null
+++ b/talk/base/task.cc
@@ -0,0 +1,289 @@
+/*
+ * libjingle
+ * Copyright 2004--2006, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "talk/base/task.h"
+#include "talk/base/common.h"
+#include "talk/base/taskrunner.h"
+
+namespace talk_base {
+
+int32 Task::unique_id_seed_ = 0;
+
+Task::Task(TaskParent *parent)
+ : TaskParent(this, parent),
+ state_(STATE_INIT),
+ blocked_(false),
+ done_(false),
+ aborted_(false),
+ busy_(false),
+ error_(false),
+ start_time_(0),
+ timeout_time_(0),
+ timeout_seconds_(0),
+ timeout_suspended_(false) {
+ unique_id_ = unique_id_seed_++;
+
+ // sanity check that we didn't roll-over our id seed
+ ASSERT(unique_id_ < unique_id_seed_);
+}
+
+Task::~Task() {
+ // Is this task being deleted in the correct manner?
+ ASSERT(!done_ || GetRunner()->is_ok_to_delete(this));
+ ASSERT(state_ == STATE_INIT || done_);
+ ASSERT(state_ == STATE_INIT || blocked_);
+
+ // If the task is being deleted without being done, it
+ // means that it hasn't been removed from its parent.
+ // This happens if a task is deleted outside of TaskRunner.
+ if (!done_) {
+ Stop();
+ }
+}
+
+int64 Task::CurrentTime() {
+ return GetRunner()->CurrentTime();
+}
+
+int64 Task::ElapsedTime() {
+ return CurrentTime() - start_time_;
+}
+
+void Task::Start() {
+ if (state_ != STATE_INIT)
+ return;
+ // Set the start time before starting the task. Otherwise if the task
+ // finishes quickly and deletes the Task object, setting start_time_
+ // will crash.
+ start_time_ = CurrentTime();
+ GetRunner()->StartTask(this);
+}
+
+void Task::Step() {
+ if (done_) {
+#ifdef _DEBUG
+ // we do not know how !blocked_ happens when done_ - should be impossible.
+ // But it causes problems, so in retail build, we force blocked_, and
+ // under debug we assert.
+ ASSERT(blocked_);
+#else
+ blocked_ = true;
+#endif
+ return;
+ }
+
+ // Async Error() was called
+ if (error_) {
+ done_ = true;
+ state_ = STATE_ERROR;
+ blocked_ = true;
+// obsolete - an errored task is not considered done now
+// SignalDone();
+
+ Stop();
+#ifdef _DEBUG
+ // verify that stop removed this from its parent
+ ASSERT(!parent()->IsChildTask(this));
+#endif
+ return;
+ }
+
+ busy_ = true;
+ int new_state = Process(state_);
+ busy_ = false;
+
+ if (aborted_) {
+ Abort(true); // no need to wake because we're awake
+ return;
+ }
+
+ if (new_state == STATE_BLOCKED) {
+ blocked_ = true;
+ // Let the timeout continue
+ } else {
+ state_ = new_state;
+ blocked_ = false;
+ ResetTimeout();
+ }
+
+ if (new_state == STATE_DONE) {
+ done_ = true;
+ } else if (new_state == STATE_ERROR) {
+ done_ = true;
+ error_ = true;
+ }
+
+ if (done_) {
+// obsolete - call this yourself
+// SignalDone();
+
+ Stop();
+#if _DEBUG
+ // verify that stop removed this from its parent
+ ASSERT(!parent()->IsChildTask(this));
+#endif
+ blocked_ = true;
+ }
+}
+
+void Task::Abort(bool nowake) {
+ // Why only check for done_ (instead of "aborted_ || done_")?
+ //
+ // If aborted_ && !done_, it means the logic for aborting still
+ // needs to be executed (because busy_ must have been true when
+ // Abort() was previously called).
+ if (done_)
+ return;
+ aborted_ = true;
+ if (!busy_) {
+ done_ = true;
+ blocked_ = true;
+ error_ = true;
+
+ // "done_" is set before calling "Stop()" to ensure that this code
+ // doesn't execute more than once (recursively) for the same task.
+ Stop();
+#ifdef _DEBUG
+ // verify that stop removed this from its parent
+ ASSERT(!parent()->IsChildTask(this));
+#endif
+ if (!nowake) {
+ // WakeTasks to self-delete.
+ // Don't call Wake() because it is a no-op after "done_" is set.
+ // Even if Wake() did run, it clears "blocked_" which isn't desireable.
+ GetRunner()->WakeTasks();
+ }
+ }
+}
+
+void Task::Wake() {
+ if (done_)
+ return;
+ if (blocked_) {
+ blocked_ = false;
+ GetRunner()->WakeTasks();
+ }
+}
+
+void Task::Error() {
+ if (error_ || done_)
+ return;
+ error_ = true;
+ Wake();
+}
+
+std::string Task::GetStateName(int state) const {
+ switch (state) {
+ case STATE_BLOCKED: return "BLOCKED";
+ case STATE_INIT: return "INIT";
+ case STATE_START: return "START";
+ case STATE_DONE: return "DONE";
+ case STATE_ERROR: return "ERROR";
+ case STATE_RESPONSE: return "RESPONSE";
+ }
+ return "??";
+}
+
+int Task::Process(int state) {
+ int newstate = STATE_ERROR;
+
+ if (TimedOut()) {
+ ClearTimeout();
+ newstate = OnTimeout();
+ SignalTimeout();
+ } else {
+ switch (state) {
+ case STATE_INIT:
+ newstate = STATE_START;
+ break;
+ case STATE_START:
+ newstate = ProcessStart();
+ break;
+ case STATE_RESPONSE:
+ newstate = ProcessResponse();
+ break;
+ case STATE_DONE:
+ case STATE_ERROR:
+ newstate = STATE_BLOCKED;
+ break;
+ }
+ }
+
+ return newstate;
+}
+
+void Task::Stop() {
+ // No need to wake because we're either awake or in abort
+ TaskParent::OnStopped(this);
+}
+
+void Task::set_timeout_seconds(const int timeout_seconds) {
+ timeout_seconds_ = timeout_seconds;
+ ResetTimeout();
+}
+
+bool Task::TimedOut() {
+ return timeout_seconds_ &&
+ timeout_time_ &&
+ CurrentTime() >= timeout_time_;
+}
+
+void Task::ResetTimeout() {
+ int64 previous_timeout_time = timeout_time_;
+ bool timeout_allowed = (state_ != STATE_INIT)
+ && (state_ != STATE_DONE)
+ && (state_ != STATE_ERROR);
+ if (timeout_seconds_ && timeout_allowed && !timeout_suspended_)
+ timeout_time_ = CurrentTime() +
+ (timeout_seconds_ * kSecToMsec * kMsecTo100ns);
+ else
+ timeout_time_ = 0;
+
+ GetRunner()->UpdateTaskTimeout(this, previous_timeout_time);
+}
+
+void Task::ClearTimeout() {
+ int64 previous_timeout_time = timeout_time_;
+ timeout_time_ = 0;
+ GetRunner()->UpdateTaskTimeout(this, previous_timeout_time);
+}
+
+void Task::SuspendTimeout() {
+ if (!timeout_suspended_) {
+ timeout_suspended_ = true;
+ ResetTimeout();
+ }
+}
+
+void Task::ResumeTimeout() {
+ if (timeout_suspended_) {
+ timeout_suspended_ = false;
+ ResetTimeout();
+ }
+}
+
+} // namespace talk_base