Added Random.cpp

1 files changed, 13 insertions, 130 deletions

diff --git a/cpp/src/IceUtil/UUID.cpp b/cpp/src/IceUtil/UUID.cpp
index afd99eaf55f..169dcf32eef 100644
--- a/cpp/src/IceUtil/UUID.cpp
+++ b/cpp/src/IceUtil/UUID.cpp
@@ -17,11 +17,7 @@
 #ifdef _WIN32
 #   include <rpc.h>
 #else
-#   include <IceUtil/StaticMutex.h>
-#   include <sys/types.h>
-#   include <sys/stat.h>
-#   include <fcntl.h>
-#   include <unistd.h>
+#   include <IceUtil/Random.h>
 #endif
 
 using namespace std;
@@ -49,75 +45,6 @@ inline void bytesToHex(unsigned char* bytes, size_t len, char*& hexBuffer)
     }
 }
 
-
-IceUtil::UUIDGenerationException::UUIDGenerationException(const char* file, int line) :
-    Exception(file, line)
-{
-}
-
-const char* IceUtil::UUIDGenerationException::_name = "IceUtil::UUIDGenerationException";
-
-#ifndef _WIN32
-//
-// Unfortunately on Linux (at least up to 2.6.9), concurrent access to /dev/urandom
-// can return the same value. Search for "Concurrent access to /dev/urandom" in the 
-// linux-kernel mailing list archive for additional details.
-// Since /dev/urandom on other platforms is usually a port from Linux, this problem 
-// could be widespread. Therefore, instead of using 122 random bits that could be 
-// duplicated, we replace the last 15 bits of all "random" UUIDs by the last 15 bits 
-// of the process id, and in each process, we serialize access to /dev/urandom using 
-// a static mutex.
-//
-
-static IceUtil::StaticMutex staticMutex = ICE_STATIC_MUTEX_INITIALIZER;
-static int fd = -1;
-static char myPid[2];
-
-namespace
-{
-
-//
-// Close fd at exit
-//
-class UUIDCleanup
-{
-public:
-    
-    ~UUIDCleanup()
-    {
-         IceUtil::StaticMutex::Lock lock(staticMutex);
-	 if(fd != -1)
-	 {
-	     close(fd);
-	     fd = -1;
-	 }
-    }
-};
-static UUIDCleanup uuidCleanup;
-}
-
-
-#endif
-
-const string
-IceUtil::UUIDGenerationException::ice_name() const
-{
-    return _name;
-}
-
-IceUtil::Exception*
-IceUtil::UUIDGenerationException::ice_clone() const
-{
-    return new UUIDGenerationException(*this);
-}
-
-void
-IceUtil::UUIDGenerationException::ice_throw() const
-{
-    throw *this;
-}
-
-
 string
 IceUtil::generateUUID()
 {
@@ -149,62 +76,18 @@ IceUtil::generateUUID()
 
     assert(sizeof(UUID) == 16);
 
+    // 
+    // Get a random sequence of bytes and the pid of the current
+    // process. Instead of using 122 random bits that could be
+    // duplicated (because of a bug with some Linux kernels and
+    // potentially other Unix platforms -- see comment in Random.cpp),
+    // we replace the last 15 bits of all "random" Randoms by the last
+    // 15 bits of the process id.
+    //
     char* buffer = reinterpret_cast<char*>(&uuid);
-    int reads = 0;
-    size_t index = 0;
+    char pid[2];
+    generateRandomAndGetPid(buffer, sizeof(UUID), pid);
 
-    {
-	//
-	// Serialize access to /dev/urandom; see comment above.
-	//
-	IceUtil::StaticMutex::Lock lock(staticMutex);
-	if(fd == -1)
-	{
-	    fd = open("/dev/urandom", O_RDONLY);
-	    if (fd == -1)
-	    {
-		assert(0);
-		throw UUIDGenerationException(__FILE__, __LINE__);
-	    }
-	    
-	    //
-	    // Initialize myPid as well
-	    // 
-	    pid_t pid = getpid();
-	    myPid[0] = (pid >> 8) & 0x7F;
-	    myPid[1] = pid & 0xFF;
-	}
-	
-
-	//
-	// Limit the number of attempts to 20 reads to avoid
-	// a potential "for ever" loop
-	//
-	while(reads <= 20 && index != sizeof(UUID))
-	{
-	    ssize_t bytesRead = read(fd, buffer + index, sizeof(UUID) - index);
-	    
-	    if(bytesRead == -1 && errno != EINTR)
-	    {
-		int err = errno;
-		cerr << "Reading /dev/urandom returned " << strerror(err) << endl;
-		assert(0);
-		throw UUIDGenerationException(__FILE__, __LINE__);
-	    }
-	    else
-	    {
-		index += bytesRead;
-		reads++;
-	    }
-	}
-    }
-	
-    if (index != sizeof(UUID))
-    {
-	assert(0);
-	throw UUIDGenerationException(__FILE__, __LINE__);
-    }
-   
     //
     // Adjust the bits that say "version 4" UUID
     //
@@ -216,8 +99,8 @@ IceUtil::generateUUID()
     //
     // Replace the end of the node by myPid (15 bits) 
     //
-    uuid.node[4] = (uuid.node[4] & 0x80) | myPid[0];
-    uuid.node[5] = myPid[1];
+    uuid.node[4] = (uuid.node[4] & 0x80) | pid[0];
+    uuid.node[5] = pid[1];
 
     //
     // Convert to a UUID string