imprecise mark and sweep native memory leak detector

libmemunreachable uses an imprecise mark and sweep pass over all memory
allocated by jemalloc in order to find unreachable allocations.

Change-Id: Ia70bbf31f5b40ff71dab28cfd6cd06c5ef01a2d4

1 files changed, 201 insertions, 0 deletions

diff --git a/libmemunreachable/LeakPipe.h b/libmemunreachable/LeakPipe.h
new file mode 100644
index 000000000..3f4e0b70d
--- /dev/null
+++ b/libmemunreachable/LeakPipe.h
@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef LIBMEMUNREACHABLE_LEAK_PIPE_H_
+#define LIBMEMUNREACHABLE_LEAK_PIPE_H_
+
+#include <sys/socket.h>
+
+#include <vector>
+
+#include "android-base/macros.h"
+
+#include "ScopedPipe.h"
+#include "log.h"
+
+// LeakPipe implements a pipe that can transfer vectors of simple objects
+// between processes.  The pipe is created in the sending process and
+// transferred over a socketpair that was created before forking.  This ensures
+// that only the sending process can have the send side of the pipe open, so if
+// the sending process dies the pipe will close.
+class LeakPipe {
+ public:
+  LeakPipe() {
+    int ret = socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, sv_);
+    if (ret < 0) {
+      LOG_ALWAYS_FATAL("failed to create socketpair: %s", strerror(errno));
+    }
+  }
+
+  ~LeakPipe() {
+    Close();
+  }
+
+  void Close() {
+    close(sv_[0]);
+    close(sv_[1]);
+    sv_[0] = -1;
+    sv_[1] = -1;
+  }
+
+  bool OpenReceiver() {
+    int fd = ReceiveFd(sv_[0]);
+    if (fd < 0) {
+      return false;
+    }
+
+    receiver_.SetFd(fd);
+    return true;
+  }
+
+  bool OpenSender() {
+    ScopedPipe pipe;
+
+    if (!SendFd(sv_[1], pipe.Receiver())) {
+      return false;
+    }
+    pipe.ReleaseReceiver();
+
+    sender_.SetFd(pipe.ReleaseSender());
+    return true;
+  }
+
+  class LeakPipeBase {
+   public:
+    LeakPipeBase() : fd_(-1) {}
+
+    ~LeakPipeBase() {
+      Close();
+    }
+
+    void SetFd(int fd) {
+      fd_ = fd;
+    }
+
+    void Close() {
+      close(fd_);
+      fd_ = -1;
+    }
+
+   protected:
+    int fd_;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(LeakPipeBase);
+  };
+
+  class LeakPipeSender : public LeakPipeBase {
+   public:
+    using LeakPipeBase::LeakPipeBase;
+
+    template<typename T>
+    bool Send(const T& value) {
+      ssize_t ret = TEMP_FAILURE_RETRY(write(fd_, &value, sizeof(T)));
+      if (ret < 0) {
+        ALOGE("failed to send value: %s", strerror(errno));
+        return false;
+      } else if (static_cast<size_t>(ret) != sizeof(T)) {
+        ALOGE("eof while writing value");
+        return false;
+      }
+
+      return true;
+    }
+
+    template<class T, class Alloc = std::allocator<T>>
+    bool SendVector(const std::vector<T, Alloc>& vector) {
+      size_t size = vector.size() * sizeof(T);
+      if (!Send(size)) {
+        return false;
+      }
+
+      ssize_t ret = TEMP_FAILURE_RETRY(write(fd_, vector.data(), size));
+      if (ret < 0) {
+        ALOGE("failed to send vector: %s", strerror(errno));
+        return false;
+      } else if (static_cast<size_t>(ret) != size) {
+        ALOGE("eof while writing vector");
+        return false;
+      }
+
+      return true;
+    }
+  };
+
+  class LeakPipeReceiver : public LeakPipeBase {
+   public:
+    using LeakPipeBase::LeakPipeBase;
+
+    template<typename T>
+    bool Receive(T* value) {
+      ssize_t ret = TEMP_FAILURE_RETRY(read(fd_, reinterpret_cast<void*>(value), sizeof(T)));
+      if (ret < 0) {
+        ALOGE("failed to receive value: %s", strerror(errno));
+        return false;
+      } else if (static_cast<size_t>(ret) != sizeof(T)) {
+        ALOGE("eof while receiving value");
+        return false;
+      }
+
+      return true;
+    }
+
+    template<class T, class Alloc = std::allocator<T>>
+    bool ReceiveVector(std::vector<T, Alloc>& vector) {
+      size_t size = 0;
+      if (!Receive(&size)) {
+        return false;
+      }
+
+      vector.resize(size / sizeof(T));
+
+      char* ptr = reinterpret_cast<char*>(vector.data());
+      while (size > 0) {
+        ssize_t ret = TEMP_FAILURE_RETRY(read(fd_, ptr, size));
+        if (ret < 0) {
+          ALOGE("failed to send vector: %s", strerror(errno));
+          return false;
+        } else if (ret == 0) {
+          ALOGE("eof while reading vector");
+          return false;
+        }
+        size -= ret;
+        ptr += ret;
+      }
+
+      return true;
+    }
+
+  };
+
+  LeakPipeReceiver& Receiver() {
+    return receiver_;
+  }
+
+  LeakPipeSender& Sender() {
+    return sender_;
+  }
+
+ private:
+  LeakPipeReceiver receiver_;
+  LeakPipeSender sender_;
+  bool SendFd(int sock, int fd);
+  int ReceiveFd(int sock);
+  DISALLOW_COPY_AND_ASSIGN(LeakPipe);
+  int sv_[2];
+};
+
+#endif // LIBMEMUNREACHABLE_LEAK_PIPE_H_