Cache device descriptors in Device_EntropySource

2 files changed, 45 insertions, 34 deletions

diff --git a/src/entropy/dev_random/es_dev.cpp b/src/entropy/dev_random/es_dev.cpp
index 04b3a90ee..b185eae75 100644
--- a/src/entropy/dev_random/es_dev.cpp
+++ b/src/entropy/dev_random/es_dev.cpp
@@ -12,29 +12,18 @@
 
 namespace Botan {
 
-namespace {
-
-/*************************************************
-* A class handling reading from a device         *
-*************************************************/
-class Device_Reader
+/**
+Close the device, if open
+*/
+Device_EntropySource::Device_Reader::~Device_Reader()
    {
-   public:
-      typedef int fd_type;
-
-      Device_Reader(fd_type device_fd) : fd(device_fd) {}
-      ~Device_Reader() { if(fd > 0) { ::close(fd); } }
-      u32bit get(byte out[], u32bit length);
-
-      static fd_type open(const std::string& pathname);
-   private:
-      fd_type fd;
-   };
+   if(fd > 0) { ::close(fd); }
+   }
 
-/*************************************************
-* Read from a device file                        *
-*************************************************/
-u32bit Device_Reader::get(byte out[], u32bit length)
+/**
+Read bytes from a device file
+*/
+u32bit Device_EntropySource::Device_Reader::get(byte out[], u32bit length)
    {
    if(fd < 0)
       return 0;
@@ -42,7 +31,7 @@ u32bit Device_Reader::get(byte out[], u32bit length)
    if(fd >= FD_SETSIZE)
       return 0;
 
-   const u32bit READ_WAIT_MS = 10;
+   const u32bit READ_WAIT_MS = 3;
 
    fd_set read_set;
    FD_ZERO(&read_set);
@@ -70,10 +59,10 @@ u32bit Device_Reader::get(byte out[], u32bit length)
    return ret;
    }
 
-/*************************************************
-* Attempt to open a device                       *
-*************************************************/
-int Device_Reader::open(const std::string& pathname)
+/**
+Attempt to open a device
+*/
+int Device_EntropySource::Device_Reader::open(const std::string& pathname)
    {
 #ifndef O_NONBLOCK
   #define O_NONBLOCK 0
@@ -87,7 +76,14 @@ int Device_Reader::open(const std::string& pathname)
    return ::open(pathname.c_str(), flags);
    }
 
-}
+/**
+Device_EntropySource constructor
+*/
+Device_EntropySource::Device_EntropySource(const std::vector<std::string>& fsnames)
+   {
+   for(u32bit i = 0; i != fsnames.size(); ++i)
+      devices.push_back(Device_Reader(Device_Reader::open(fsnames[i])));
+   }
 
 /**
 * Gather entropy from a RNG device
@@ -96,11 +92,9 @@ u32bit Device_EntropySource::slow_poll(byte output[], u32bit length)
    {
    u32bit read = 0;
 
-   for(size_t j = 0; j != fsnames.size(); ++j)
+   for(size_t i = 0; i != devices.size(); ++i)
       {
-      Device_Reader reader(Device_Reader::open(fsnames[j]));
-
-      read += reader.get(output + read, length - read);
+      read += devices[i].get(output + read, length - read);
 
       if(read == length)
          break;
diff --git a/src/entropy/dev_random/es_dev.h b/src/entropy/dev_random/es_dev.h
index 2c9d93369..ff6a14f2c 100644
--- a/src/entropy/dev_random/es_dev.h
+++ b/src/entropy/dev_random/es_dev.h
@@ -20,13 +20,30 @@ class BOTAN_DLL Device_EntropySource : public EntropySource
    public:
       std::string name() const { return "RNG Device Reader"; }
 
-      Device_EntropySource(const std::vector<std::string>& fs) :
-         fsnames(fs) {}
+      Device_EntropySource(const std::vector<std::string>& fsnames);
 
       u32bit slow_poll(byte[], u32bit);
       u32bit fast_poll(byte[], u32bit);
    private:
-      std::vector<std::string> fsnames;
+
+      /**
+      A class handling reading from a Unix character device
+      */
+      class Device_Reader
+         {
+         public:
+            typedef int fd_type;
+
+            Device_Reader(fd_type device_fd) : fd(device_fd) {}
+            ~Device_Reader();
+            u32bit get(byte out[], u32bit length);
+
+            static fd_type open(const std::string& pathname);
+         private:
+            fd_type fd;
+         };
+
+      std::vector<Device_Reader> devices;
    };
 
 }