Implement DDMS heap info ("HPIF") chunks.

This lets you see how many bytes/objects are in your managed heap.

Change-Id: Ie925207e9c48989a24968633e60b99314d220865
diff --git a/src/debugger.cc b/src/debugger.cc
index f7e80d3..3321d68 100644
--- a/src/debugger.cc
+++ b/src/debugger.cc
@@ -233,7 +233,7 @@
 void Dbg::GcDidFinish() {
   if (gDdmHpifWhen != HPIF_WHEN_NEVER) {
     LOG(DEBUG) << "Sending VM heap info to DDM";
-    DdmSendHeapInfo(gDdmHpifWhen, false);
+    DdmSendHeapInfo(gDdmHpifWhen);
   }
   if (gDdmHpsgWhen != HPSG_WHEN_NEVER) {
     LOG(DEBUG) << "Dumping VM heap to DDM";
@@ -867,7 +867,7 @@
 
 int Dbg::DdmHandleHpifChunk(HpifWhen when) {
   if (when == HPIF_WHEN_NOW) {
-    DdmSendHeapInfo(when, true);
+    DdmSendHeapInfo(when);
     return true;
   }
 
@@ -901,8 +901,43 @@
   return true;
 }
 
-void Dbg::DdmSendHeapInfo(HpifWhen reason, bool shouldLock) {
-  UNIMPLEMENTED(WARNING) << "reason=" << static_cast<int>(reason) << " shouldLock=" << shouldLock;
+void Dbg::DdmSendHeapInfo(HpifWhen reason) {
+  // If there's a one-shot 'when', reset it.
+  if (reason == gDdmHpifWhen) {
+    if (gDdmHpifWhen == HPIF_WHEN_NEXT_GC) {
+      gDdmHpifWhen = HPIF_WHEN_NEVER;
+    }
+  }
+
+  /*
+   * Chunk HPIF (client --> server)
+   *
+   * Heap Info. General information about the heap,
+   * suitable for a summary display.
+   *
+   *   [u4]: number of heaps
+   *
+   *   For each heap:
+   *     [u4]: heap ID
+   *     [u8]: timestamp in ms since Unix epoch
+   *     [u1]: capture reason (same as 'when' value from server)
+   *     [u4]: max heap size in bytes (-Xmx)
+   *     [u4]: current heap size in bytes
+   *     [u4]: current number of bytes allocated
+   *     [u4]: current number of objects allocated
+   */
+  uint8_t heap_count = 1;
+  std::vector<uint8_t> bytes(4 + (heap_count * (4 + 8 + 1 + 4 + 4 + 4 + 4)));
+  uint8_t* dst = &bytes[0];
+  JDWP::Write4BE(&dst, heap_count);
+  JDWP::Write4BE(&dst, 1); // Heap id (bogus; we only have one heap).
+  JDWP::Write8BE(&dst, MilliTime());
+  JDWP::Write1BE(&dst, reason);
+  JDWP::Write4BE(&dst, Heap::GetMaxMemory()); // Max allowed heap size in bytes.
+  JDWP::Write4BE(&dst, Heap::GetTotalMemory()); // Current heap size in bytes.
+  JDWP::Write4BE(&dst, Heap::GetBytesAllocated());
+  JDWP::Write4BE(&dst, Heap::GetObjectsAllocated());
+  Dbg::DdmSendChunk(CHUNK_TYPE("HPIF"), bytes.size(), &bytes[0]);
 }
 
 void Dbg::DdmSendHeapSegments(bool shouldLock, bool native) {
diff --git a/src/debugger.h b/src/debugger.h
index a818a48..85cc1f8 100644
--- a/src/debugger.h
+++ b/src/debugger.h
@@ -257,7 +257,7 @@
   };
   static bool DdmHandleHpsgNhsgChunk(HpsgWhen when, HpsgWhat what, bool native);
 
-  static void DdmSendHeapInfo(HpifWhen reason, bool shouldLock);
+  static void DdmSendHeapInfo(HpifWhen reason);
   static void DdmSendHeapSegments(bool shouldLock, bool native);
 };
 
diff --git a/src/heap.cc b/src/heap.cc
index 555569a..9fe7750 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -405,18 +405,15 @@
 }
 
 int64_t Heap::GetMaxMemory() {
-  UNIMPLEMENTED(WARNING);
-  return 0;
+  return maximum_size_;
 }
 
 int64_t Heap::GetTotalMemory() {
-  UNIMPLEMENTED(WARNING);
-  return 0;
+  return alloc_space_->Size();
 }
 
 int64_t Heap::GetFreeMemory() {
-  UNIMPLEMENTED(WARNING);
-  return 0;
+  return alloc_space_->Size() - num_bytes_allocated_;
 }
 
 class InstanceCounter {
@@ -523,14 +520,14 @@
   bool is_small = (bytes_freed > 0 && bytes_freed < 1024);
   size_t kib_freed = (bytes_freed > 0 ? std::max(bytes_freed/1024, 1U) : 0);
 
-  size_t footprint = alloc_space_->Size();
-  size_t percentFree = 100 - static_cast<size_t>(100.0f * float(num_bytes_allocated_) / footprint);
+  size_t total = GetTotalMemory();
+  size_t percentFree = 100 - static_cast<size_t>(100.0f * float(num_bytes_allocated_) / total);
 
   uint32_t duration = (t1 - t0)/1000/1000;
   if (is_verbose_gc_) {
     LOG(INFO) << "GC freed " << (is_small ? "<" : "") << kib_freed << "KiB, "
               << percentFree << "% free "
-              << (num_bytes_allocated_/1024) << "KiB/" << (footprint/1024) << "KiB, "
+              << (num_bytes_allocated_/1024) << "KiB/" << (total/1024) << "KiB, "
               << "paused " << duration << "ms";
   }
   Dbg::GcDidFinish();
diff --git a/src/heap.h b/src/heap.h
index 9e21272..2e80571 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -175,6 +175,9 @@
 
   static void AddFinalizerReference(Object* object);
 
+  static size_t GetBytesAllocated() { return num_bytes_allocated_; }
+  static size_t GetObjectsAllocated() { return num_objects_allocated_; }
+
  private:
   // Allocates uninitialized storage.
   static Object* AllocateLocked(size_t num_bytes);
diff --git a/src/jdwp/jdwp_bits.h b/src/jdwp/jdwp_bits.h
index 59ece03..3b951f9 100644
--- a/src/jdwp/jdwp_bits.h
+++ b/src/jdwp/jdwp_bits.h
@@ -107,6 +107,26 @@
   *buf = (uint8_t)(val);
 }
 
+static inline void Write1BE(uint8_t** dst, uint8_t value) {
+  Set1(*dst, value);
+  *dst += sizeof(value);
+}
+
+static inline void Write2BE(uint8_t** dst, uint16_t value) {
+  Set2BE(*dst, value);
+  *dst += sizeof(value);
+}
+
+static inline void Write4BE(uint8_t** dst, uint32_t value) {
+  Set4BE(*dst, value);
+  *dst += sizeof(value);
+}
+
+static inline void Write8BE(uint8_t** dst, uint64_t value) {
+  Set8BE(*dst, value);
+  *dst += sizeof(value);
+}
+
 /*
  * Stuff a UTF-8 string into the buffer.
  */
diff --git a/src/jdwp/jdwp_handler.cc b/src/jdwp/jdwp_handler.cc
index f408c54..04c4734 100644
--- a/src/jdwp/jdwp_handler.cc
+++ b/src/jdwp/jdwp_handler.cc
@@ -1806,7 +1806,7 @@
    * the initial setup.  Only update if this is a non-DDMS packet.
    */
   if (pHeader->cmdSet != kJDWPDdmCmdSet) {
-    QuasiAtomicSwap64(GetNowMsec(), &lastActivityWhen);
+    QuasiAtomicSwap64(MilliTime(), &lastActivityWhen);
   }
 
   /* tell the VM that GC is okay again */
diff --git a/src/jdwp/jdwp_main.cc b/src/jdwp/jdwp_main.cc
index 1df0d66..fa02895 100644
--- a/src/jdwp/jdwp_main.cc
+++ b/src/jdwp/jdwp_main.cc
@@ -412,21 +412,6 @@
  */
 
 /*
- * Get a notion of the current time, in milliseconds.
- */
-int64_t GetNowMsec() {
-#ifdef HAVE_POSIX_CLOCKS
-  struct timespec now;
-  clock_gettime(CLOCK_MONOTONIC, &now);
-  return now.tv_sec * 1000LL + now.tv_nsec / 1000000LL;
-#else
-  struct timeval now;
-  gettimeofday(&now, NULL);
-  return now.tv_sec * 1000LL + now.tv_usec / 1000LL;
-#endif
-}
-
-/*
  * 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
@@ -447,7 +432,7 @@
   }
 
   /* now get the current time */
-  int64_t now = GetNowMsec();
+  int64_t now = MilliTime();
   CHECK_GT(now, last);
 
   LOG(VERBOSE) << "+++ debugger interval=" << (now - last);
diff --git a/src/jdwp/jdwp_priv.h b/src/jdwp/jdwp_priv.h
index 46f79b8..45d70f8 100644
--- a/src/jdwp/jdwp_priv.h
+++ b/src/jdwp/jdwp_priv.h
@@ -83,9 +83,6 @@
   Mutex socket_lock_;
 };
 
-/* get current time, in msec */
-int64_t GetNowMsec();
-
 }  // namespace JDWP
 
 }  // namespace art
diff --git a/src/utils.cc b/src/utils.cc
index 639339a..4c65036 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -49,6 +49,12 @@
       ptm->tm_hour, ptm->tm_min, ptm->tm_sec);
 }
 
+uint64_t MilliTime() {
+  struct timespec now;
+  clock_gettime(CLOCK_MONOTONIC, &now);
+  return static_cast<uint64_t>(now.tv_sec) * 1000LL + now.tv_nsec / 1000000LL;
+}
+
 uint64_t NanoTime() {
   struct timespec now;
   clock_gettime(CLOCK_MONOTONIC, &now);
diff --git a/src/utils.h b/src/utils.h
index bf8191e..bb307d1 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -209,6 +209,9 @@
 // Returns the current date in ISO yyyy-mm-dd hh:mm:ss format.
 std::string GetIsoDate();
 
+// Returns the current time in milliseconds (using the POSIX CLOCK_MONOTONIC).
+uint64_t MilliTime();
+
 // Returns the current time in nanoseconds (using the POSIX CLOCK_MONOTONIC).
 uint64_t NanoTime();