1 files changed, 625 insertions, 0 deletions
diff --git a/runtime/jdwp/jdwp_main.cc b/runtime/jdwp/jdwp_main.cc
new file mode 100644
index 0000000000..3b6dd810cc
--- /dev/null
+++ b/runtime/jdwp/jdwp_main.cc
@@ -0,0 +1,625 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "atomic.h"
+#include "base/logging.h"
+#include "debugger.h"
+#include "jdwp/jdwp_priv.h"
+#include "scoped_thread_state_change.h"
+
+namespace art {
+
+namespace JDWP {
+
+static void* StartJdwpThread(void* arg);
+
+/*
+ * JdwpNetStateBase class implementation
+ */
+JdwpNetStateBase::JdwpNetStateBase(JdwpState* state)
+    : state_(state), socket_lock_("JdwpNetStateBase lock", kJdwpSerialSocketLock) {
+  clientSock = -1;
+  wake_pipe_[0] = -1;
+  wake_pipe_[1] = -1;
+  input_count_ = 0;
+  awaiting_handshake_ = false;
+}
+
+JdwpNetStateBase::~JdwpNetStateBase() {
+  if (wake_pipe_[0] != -1) {
+    close(wake_pipe_[0]);
+    wake_pipe_[0] = -1;
+  }
+  if (wake_pipe_[1] != -1) {
+    close(wake_pipe_[1]);
+    wake_pipe_[1] = -1;
+  }
+}
+
+bool JdwpNetStateBase::MakePipe() {
+  if (pipe(wake_pipe_) == -1) {
+    PLOG(ERROR) << "pipe failed";
+    return false;
+  }
+  return true;
+}
+
+void JdwpNetStateBase::WakePipe() {
+  // If we might be sitting in select, kick us loose.
+  if (wake_pipe_[1] != -1) {
+    VLOG(jdwp) << "+++ writing to wake pipe";
+    TEMP_FAILURE_RETRY(write(wake_pipe_[1], "", 1));
+  }
+}
+
+void JdwpNetStateBase::ConsumeBytes(size_t count) {
+  CHECK_GT(count, 0U);
+  CHECK_LE(count, input_count_);
+
+  if (count == input_count_) {
+    input_count_ = 0;
+    return;
+  }
+
+  memmove(input_buffer_, input_buffer_ + count, input_count_ - count);
+  input_count_ -= count;
+}
+
+bool JdwpNetStateBase::HaveFullPacket() {
+  if (awaiting_handshake_) {
+    return (input_count_ >= kMagicHandshakeLen);
+  }
+  if (input_count_ < 4) {
+    return false;
+  }
+  uint32_t length = Get4BE(input_buffer_);
+  return (input_count_ >= length);
+}
+
+bool JdwpNetStateBase::IsAwaitingHandshake() {
+  return awaiting_handshake_;
+}
+
+void JdwpNetStateBase::SetAwaitingHandshake(bool new_state) {
+  awaiting_handshake_ = new_state;
+}
+
+bool JdwpNetStateBase::IsConnected() {
+  return clientSock >= 0;
+}
+
+// Close a connection from a debugger (which may have already dropped us).
+// Resets the state so we're ready to receive a new connection.
+// Only called from the JDWP thread.
+void JdwpNetStateBase::Close() {
+  if (clientSock < 0) {
+    return;
+  }
+
+  VLOG(jdwp) << "+++ closing JDWP connection on fd " << clientSock;
+
+  close(clientSock);
+  clientSock = -1;
+}
+
+/*
+ * Write a packet. Grabs a mutex to assure atomicity.
+ */
+ssize_t JdwpNetStateBase::WritePacket(ExpandBuf* pReply) {
+  MutexLock mu(Thread::Current(), socket_lock_);
+  return TEMP_FAILURE_RETRY(write(clientSock, expandBufGetBuffer(pReply), expandBufGetLength(pReply)));
+}
+
+/*
+ * Write a buffered packet. Grabs a mutex to assure atomicity.
+ */
+ssize_t JdwpNetStateBase::WriteBufferedPacket(const iovec* iov, int iov_count) {
+  MutexLock mu(Thread::Current(), socket_lock_);
+  return TEMP_FAILURE_RETRY(writev(clientSock, iov, iov_count));
+}
+
+bool JdwpState::IsConnected() {
+  return netState != NULL && netState->IsConnected();
+}
+
+void JdwpState::SendBufferedRequest(uint32_t type, const iovec* iov, int iov_count) {
+  if (netState->clientSock < 0) {
+    // Can happen with some DDMS events.
+    VLOG(jdwp) << "Not sending JDWP packet: no debugger attached!";
+    return;
+  }
+
+  size_t expected = 0;
+  for (int i = 0; i < iov_count; ++i) {
+    expected += iov[i].iov_len;
+  }
+
+  errno = 0;
+  ssize_t actual = netState->WriteBufferedPacket(iov, iov_count);
+  if (static_cast<size_t>(actual) != expected) {
+    PLOG(ERROR) << StringPrintf("Failed to send JDWP packet %c%c%c%c to debugger (%d of %d)",
+                                static_cast<uint8_t>(type >> 24),
+                                static_cast<uint8_t>(type >> 16),
+                                static_cast<uint8_t>(type >> 8),
+                                static_cast<uint8_t>(type),
+                                actual, expected);
+  }
+}
+
+void JdwpState::SendRequest(ExpandBuf* pReq) {
+  if (netState->clientSock < 0) {
+    // Can happen with some DDMS events.
+    VLOG(jdwp) << "Not sending JDWP packet: no debugger attached!";
+    return;
+  }
+
+  errno = 0;
+  ssize_t actual = netState->WritePacket(pReq);
+  if (static_cast<size_t>(actual) != expandBufGetLength(pReq)) {
+    PLOG(ERROR) << StringPrintf("Failed to send JDWP packet to debugger (%d of %d)",
+                                actual, expandBufGetLength(pReq));
+  }
+}
+
+/*
+ * Get the next "request" serial number.  We use this when sending
+ * packets to the debugger.
+ */
+uint32_t JdwpState::NextRequestSerial() {
+  MutexLock mu(Thread::Current(), serial_lock_);
+  return request_serial_++;
+}
+
+/*
+ * Get the next "event" serial number.  We use this in the response to
+ * message type EventRequest.Set.
+ */
+uint32_t JdwpState::NextEventSerial() {
+  MutexLock mu(Thread::Current(), serial_lock_);
+  return event_serial_++;
+}
+
+JdwpState::JdwpState(const JdwpOptions* options)
+    : options_(options),
+      thread_start_lock_("JDWP thread start lock", kJdwpStartLock),
+      thread_start_cond_("JDWP thread start condition variable", thread_start_lock_),
+      pthread_(0),
+      thread_(NULL),
+      debug_thread_started_(false),
+      debug_thread_id_(0),
+      run(false),
+      netState(NULL),
+      attach_lock_("JDWP attach lock", kJdwpAttachLock),
+      attach_cond_("JDWP attach condition variable", attach_lock_),
+      last_activity_time_ms_(0),
+      serial_lock_("JDWP serial lock", kJdwpSerialSocketLock),
+      request_serial_(0x10000000),
+      event_serial_(0x20000000),
+      event_list_lock_("JDWP event list lock", kJdwpEventListLock),
+      event_list_(NULL),
+      event_list_size_(0),
+      event_thread_lock_("JDWP event thread lock"),
+      event_thread_cond_("JDWP event thread condition variable", event_thread_lock_),
+      event_thread_id_(0),
+      ddm_is_active_(false),
+      should_exit_(false),
+      exit_status_(0) {
+}
+
+/*
+ * Initialize JDWP.
+ *
+ * Does not return until JDWP thread is running, but may return before
+ * the thread is accepting network connections.
+ */
+JdwpState* JdwpState::Create(const JdwpOptions* options) {
+  Thread* self = Thread::Current();
+  Locks::mutator_lock_->AssertNotHeld(self);
+  UniquePtr<JdwpState> state(new JdwpState(options));
+  switch (options->transport) {
+  case kJdwpTransportSocket:
+    InitSocketTransport(state.get(), options);
+    break;
+#ifdef HAVE_ANDROID_OS
+  case kJdwpTransportAndroidAdb:
+    InitAdbTransport(state.get(), options);
+    break;
+#endif
+  default:
+    LOG(FATAL) << "Unknown transport: " << options->transport;
+  }
+
+  /*
+   * Grab a mutex or two before starting the thread.  This ensures they
+   * won't signal the cond var before we're waiting.
+   */
+  {
+    MutexLock thread_start_locker(self, state->thread_start_lock_);
+    const bool should_suspend = options->suspend;
+    if (!should_suspend) {
+      /*
+       * We have bound to a port, or are trying to connect outbound to a
+       * debugger.  Create the JDWP thread and let it continue the mission.
+       */
+      CHECK_PTHREAD_CALL(pthread_create, (&state->pthread_, NULL, StartJdwpThread, state.get()), "JDWP thread");
+
+      /*
+       * Wait until the thread finishes basic initialization.
+       * TODO: cond vars should be waited upon in a loop
+       */
+      state->thread_start_cond_.Wait(self);
+    } else {
+      {
+        /*
+         * We have bound to a port, or are trying to connect outbound to a
+         * debugger.  Create the JDWP thread and let it continue the mission.
+         */
+        CHECK_PTHREAD_CALL(pthread_create, (&state->pthread_, NULL, StartJdwpThread, state.get()), "JDWP thread");
+
+        /*
+         * Wait until the thread finishes basic initialization.
+         * TODO: cond vars should be waited upon in a loop
+         */
+        state->thread_start_cond_.Wait(self);
+
+        /*
+         * For suspend=y, wait for the debugger to connect to us or for us to
+         * connect to the debugger.
+         *
+         * The JDWP thread will signal us when it connects successfully or
+         * times out (for timeout=xxx), so we have to check to see what happened
+         * when we wake up.
+         */
+        {
+          ScopedThreadStateChange tsc(self, kWaitingForDebuggerToAttach);
+          MutexLock attach_locker(self, state->attach_lock_);
+          state->attach_cond_.Wait(self);
+        }
+      }
+      if (!state->IsActive()) {
+        LOG(ERROR) << "JDWP connection failed";
+        return NULL;
+      }
+
+      LOG(INFO) << "JDWP connected";
+
+      /*
+       * Ordinarily we would pause briefly to allow the debugger to set
+       * breakpoints and so on, but for "suspend=y" the VM init code will
+       * pause the VM when it sends the VM_START message.
+       */
+    }
+  }
+
+  return state.release();
+}
+
+/*
+ * Reset all session-related state.  There should not be an active connection
+ * to the client at this point.  The rest of the VM still thinks there is
+ * a debugger attached.
+ *
+ * This includes freeing up the debugger event list.
+ */
+void JdwpState::ResetState() {
+  /* could reset the serial numbers, but no need to */
+
+  UnregisterAll();
+  {
+    MutexLock mu(Thread::Current(), event_list_lock_);
+    CHECK(event_list_ == NULL);
+  }
+
+  /*
+   * Should not have one of these in progress.  If the debugger went away
+   * mid-request, though, we could see this.
+   */
+  if (event_thread_id_ != 0) {
+    LOG(WARNING) << "Resetting state while event in progress";
+    DCHECK(false);
+  }
+}
+
+/*
+ * Tell the JDWP thread to shut down.  Frees "state".
+ */
+JdwpState::~JdwpState() {
+  if (netState != NULL) {
+    if (IsConnected()) {
+      PostVMDeath();
+    }
+
+    /*
+     * Close down the network to inspire the thread to halt.
+     */
+    VLOG(jdwp) << "JDWP shutting down net...";
+    netState->Shutdown();
+
+    if (debug_thread_started_) {
+      run = false;
+      void* threadReturn;
+      if (pthread_join(pthread_, &threadReturn) != 0) {
+        LOG(WARNING) << "JDWP thread join failed";
+      }
+    }
+
+    VLOG(jdwp) << "JDWP freeing netstate...";
+    delete netState;
+    netState = NULL;
+  }
+  CHECK(netState == NULL);
+
+  ResetState();
+}
+
+/*
+ * Are we talking to a debugger?
+ */
+bool JdwpState::IsActive() {
+  return IsConnected();
+}
+
+// Returns "false" if we encounter a connection-fatal error.
+bool JdwpState::HandlePacket() {
+  JdwpNetStateBase* netStateBase = reinterpret_cast<JdwpNetStateBase*>(netState);
+  JDWP::Request request(netStateBase->input_buffer_, netStateBase->input_count_);
+
+  ExpandBuf* pReply = expandBufAlloc();
+  ProcessRequest(request, pReply);
+  ssize_t cc = netStateBase->WritePacket(pReply);
+  if (cc != (ssize_t) expandBufGetLength(pReply)) {
+    PLOG(ERROR) << "Failed sending reply to debugger";
+    expandBufFree(pReply);
+    return false;
+  }
+  expandBufFree(pReply);
+  netStateBase->ConsumeBytes(request.GetLength());
+  return true;
+}
+
+/*
+ * Entry point for JDWP thread.  The thread was created through the VM
+ * mechanisms, so there is a java/lang/Thread associated with us.
+ */
+static void* StartJdwpThread(void* arg) {
+  JdwpState* state = reinterpret_cast<JdwpState*>(arg);
+  CHECK(state != NULL);
+
+  state->Run();
+  return NULL;
+}
+
+void JdwpState::Run() {
+  Runtime* runtime = Runtime::Current();
+  CHECK(runtime->AttachCurrentThread("JDWP", true, runtime->GetSystemThreadGroup(),
+                                     !runtime->IsCompiler()));
+
+  VLOG(jdwp) << "JDWP: thread running";
+
+  /*
+   * Finish initializing, then notify the creating thread that
+   * we're running.
+   */
+  thread_ = Thread::Current();
+  run = true;
+
+  {
+    MutexLock locker(thread_, thread_start_lock_);
+    debug_thread_started_ = true;
+    thread_start_cond_.Broadcast(thread_);
+  }
+
+  /* set the thread state to kWaitingInMainDebuggerLoop so GCs don't wait for us */
+  CHECK_EQ(thread_->GetState(), kNative);
+  Locks::mutator_lock_->AssertNotHeld(thread_);
+  thread_->SetState(kWaitingInMainDebuggerLoop);
+
+  /*
+   * Loop forever if we're in server mode, processing connections.  In
+   * non-server mode, we bail out of the thread when the debugger drops
+   * us.
+   *
+   * We broadcast a notification when a debugger attaches, after we
+   * successfully process the handshake.
+   */
+  while (run) {
+    if (options_->server) {
+      /*
+       * Block forever, waiting for a connection.  To support the
+       * "timeout=xxx" option we'll need to tweak this.
+       */
+      if (!netState->Accept()) {
+        break;
+      }
+    } else {
+      /*
+       * If we're not acting as a server, we need to connect out to the
+       * debugger.  To support the "timeout=xxx" option we need to
+       * have a timeout if the handshake reply isn't received in a
+       * reasonable amount of time.
+       */
+      if (!netState->Establish(options_)) {
+        /* wake anybody who was waiting for us to succeed */
+        MutexLock mu(thread_, attach_lock_);
+        attach_cond_.Broadcast(thread_);
+        break;
+      }
+    }
+
+    /* prep debug code to handle the new connection */
+    Dbg::Connected();
+
+    /* process requests until the debugger drops */
+    bool first = true;
+    while (!Dbg::IsDisposed()) {
+      {
+        // sanity check -- shouldn't happen?
+        MutexLock mu(thread_, *Locks::thread_suspend_count_lock_);
+        CHECK_EQ(thread_->GetState(), kWaitingInMainDebuggerLoop);
+      }
+
+      if (!netState->ProcessIncoming()) {
+        /* blocking read */
+        break;
+      }
+
+      if (should_exit_) {
+        exit(exit_status_);
+      }
+
+      if (first && !netState->IsAwaitingHandshake()) {
+        /* handshake worked, tell the interpreter that we're active */
+        first = false;
+
+        /* set thread ID; requires object registry to be active */
+        {
+          ScopedObjectAccess soa(thread_);
+          debug_thread_id_ = Dbg::GetThreadSelfId();
+        }
+
+        /* wake anybody who's waiting for us */
+        MutexLock mu(thread_, attach_lock_);
+        attach_cond_.Broadcast(thread_);
+      }
+    }
+
+    netState->Close();
+
+    if (ddm_is_active_) {
+      ddm_is_active_ = false;
+
+      /* broadcast the disconnect; must be in RUNNING state */
+      thread_->TransitionFromSuspendedToRunnable();
+      Dbg::DdmDisconnected();
+      thread_->TransitionFromRunnableToSuspended(kWaitingInMainDebuggerLoop);
+    }
+
+    {
+      ScopedObjectAccess soa(thread_);
+
+      // Release session state, e.g. remove breakpoint instructions.
+      ResetState();
+    }
+    // Tell the rest of the runtime that the debugger is no longer around.
+    Dbg::Disconnected();
+
+    /* if we had threads suspended, resume them now */
+    Dbg::UndoDebuggerSuspensions();
+
+    /* if we connected out, this was a one-shot deal */
+    if (!options_->server) {
+      run = false;
+    }
+  }
+
+  /* back to native, for thread shutdown */
+  CHECK_EQ(thread_->GetState(), kWaitingInMainDebuggerLoop);
+  thread_->SetState(kNative);
+
+  VLOG(jdwp) << "JDWP: thread detaching and exiting...";
+  runtime->DetachCurrentThread();
+}
+
+void JdwpState::NotifyDdmsActive() {
+  if (!ddm_is_active_) {
+    ddm_is_active_ = true;
+    Dbg::DdmConnected();
+  }
+}
+
+Thread* JdwpState::GetDebugThread() {
+  return thread_;
+}
+
+/*
+ * Support routines for waitForDebugger().
+ *
+ * We can't have a trivial "waitForDebugger" function that returns the
+ * instant the debugger connects, because we run the risk of executing code
+ * before the debugger has had a chance to configure breakpoints or issue
+ * suspend calls.  It would be nice to just sit in the suspended state, but
+ * most debuggers don't expect any threads to be suspended when they attach.
+ *
+ * There's no JDWP event we can post to tell the debugger, "we've stopped,
+ * and we like it that way".  We could send a fake breakpoint, which should
+ * cause the debugger to immediately send a resume, but the debugger might
+ * send the resume immediately or might throw an exception of its own upon
+ * receiving a breakpoint event that it didn't ask for.
+ *
+ * What we really want is a "wait until the debugger is done configuring
+ * stuff" event.  We can approximate this with a "wait until the debugger
+ * has been idle for a brief period".
+ */
+
+/*
+ * Return the time, in milliseconds, since the last debugger activity.
+ *
+ * Returns -1 if no debugger is attached, or 0 if we're in the middle of
+ * processing a debugger request.
+ */
+int64_t JdwpState::LastDebuggerActivity() {
+  if (!Dbg::IsDebuggerActive()) {
+    LOG(DEBUG) << "no active debugger";
+    return -1;
+  }
+
+  int64_t last = QuasiAtomic::Read64(&last_activity_time_ms_);
+
+  /* initializing or in the middle of something? */
+  if (last == 0) {
+    VLOG(jdwp) << "+++ last=busy";
+    return 0;
+  }
+
+  /* now get the current time */
+  int64_t now = MilliTime();
+  CHECK_GE(now, last);
+
+  VLOG(jdwp) << "+++ debugger interval=" << (now - last);
+  return now - last;
+}
+
+void JdwpState::ExitAfterReplying(int exit_status) {
+  LOG(WARNING) << "Debugger told VM to exit with status " << exit_status;
+  should_exit_ = true;
+  exit_status_ = exit_status;
+}
+
+std::ostream& operator<<(std::ostream& os, const JdwpLocation& rhs) {
+  os << "JdwpLocation["
+     << Dbg::GetClassName(rhs.class_id) << "." << Dbg::GetMethodName(rhs.method_id)
+     << "@" << StringPrintf("%#llx", rhs.dex_pc) << " " << rhs.type_tag << "]";
+  return os;
+}
+
+bool operator==(const JdwpLocation& lhs, const JdwpLocation& rhs) {
+  return lhs.dex_pc == rhs.dex_pc && lhs.method_id == rhs.method_id &&
+      lhs.class_id == rhs.class_id && lhs.type_tag == rhs.type_tag;
+}
+
+bool operator!=(const JdwpLocation& lhs, const JdwpLocation& rhs) {
+  return !(lhs == rhs);
+}
+
+}  // namespace JDWP
+
+}  // namespace art