Fix EOF handling in AdbClient (take 2)

[labath]

Summary

AdbClient would spin in a loop in ReadAllBytes in case the remote end was closed before reading
the requested number of bytes. Make sure we return an error in this case instead.

[ovyalov]

LGTM

lldb/trunk/source/Plugins/Platform/Android/AdbClient.cpp

 #include <sstream>
 
 using namespace lldb;
 using namespace lldb_private;
 using namespace lldb_private::platform_android;
 
 namespace {
 
-const uint32_t kReadTimeout = 1000000; // 1 second
+const std::chrono::seconds kReadTimeout(4);
 const char * kOKAY = "OKAY";
 const char * kFAIL = "FAIL";
 const char * kDATA = "DATA";
 const char * kDONE = "DONE";
 
 const char * kSEND = "SEND";
 const char * kRECV = "RECV";
 const char * kSTAT = "STAT";
AdbClient::ReadSyncHeader (std::string &response_id, uint32_t &data_len)
     }
 
     return error;
 }
 
 Error
 AdbClient::ReadAllBytes (void *buffer, size_t size)
 {
+    using namespace std::chrono;
+
     Error error;
     ConnectionStatus status;
     char *read_buffer = static_cast<char*>(buffer);
 
-    size_t tota_read_bytes = 0;
-    while (tota_read_bytes < size)
-    {
-        auto read_bytes = m_conn.Read (read_buffer + tota_read_bytes, size - tota_read_bytes, kReadTimeout, status, &error);
-        if (error.Fail ())
-            return error;
-        tota_read_bytes += read_bytes;
+    auto now = steady_clock::now();
+    const auto deadline = now + kReadTimeout;
+    size_t total_read_bytes = 0;
+    while (total_read_bytes < size && now < deadline)
+    {
+        uint32_t timeout_usec = duration_cast<microseconds>(deadline - now).count();
+        auto read_bytes =
+            m_conn.Read(read_buffer + total_read_bytes, size - total_read_bytes, timeout_usec, status, &error);
+        if (error.Fail ())
+            return error;
+        total_read_bytes += read_bytes;
+        if (status != eConnectionStatusSuccess)
+            break;
+        now = steady_clock::now();
     }
+    if (total_read_bytes < size)
+        error = Error("Unable to read requested number of bytes. Connection status: %d.", status);
     return error;
 }
 
 Error
 AdbClient::Stat (const FileSpec &remote_file, uint32_t &mode, uint32_t &size, uint32_t &mtime)
 {
     auto error = StartSync ();
     if (error.Fail ())