Fixed a possible race condition in generating the DVB device names

3 files changed, 17 insertions, 11 deletions

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index e6effd04..f6c27f9b 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -345,6 +345,7 @@ Rainer Zocholl <vdrcontrib@zocki.toppoint.de>
  replaying in time shift mode
  for suggesting that VDR should stop if one of the configuration files can't be
  read correctly at program startup
+ for reporting a possible race condition in generating the DVB device names
 
 Oleg Assovski <assen@bitcom.msk.ru>
  for adding EPG scanning for another 4 days
diff --git a/HISTORY b/HISTORY
index 325a9af5..dd5a45b6 100644
--- a/HISTORY
+++ b/HISTORY
@@ -3169,3 +3169,5 @@ Video Disk Recorder Revision History
 - Fixed the spelling of 'canceling' (thanks to Wayne Keer for reporting this one).
 - Re-introduced a sleep to cDvbPlayer::Action() to avoid high CPU load in still
   picture mode (thanks to Reinhard Nissl for reporting this one).
+- Fixed a possible race condition in generating the DVB device names (thanks to
+  Rainer Zocholl for reporting this one).
diff --git a/dvbdevice.c b/dvbdevice.c
index 8780ac53..0c370c4f 100644
--- a/dvbdevice.c
+++ b/dvbdevice.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: dvbdevice.c 1.105 2004/11/20 11:41:37 kls Exp $
+ * $Id: dvbdevice.c 1.106 2004/11/27 10:24:47 kls Exp $
  */
 
 #include "dvbdevice.h"
@@ -46,16 +46,19 @@ extern "C" {
 #define DEV_DVB_AUDIO     "audio"
 #define DEV_DVB_CA        "ca"
 
-static const char *DvbName(const char *Name, int n)
-{
-  static char buffer[PATH_MAX];
-  snprintf(buffer, sizeof(buffer), "%s%d/%s%d", DEV_DVB_ADAPTER, n, Name, 0);
-  return buffer;
-}
+class cDvbName {
+private:
+  char buffer[PATH_MAX];
+public:
+  cDvbName(const char *Name, int n) {
+    snprintf(buffer, sizeof(buffer), "%s%d/%s%d", DEV_DVB_ADAPTER, n, Name, 0);
+    }
+  const char *operator*() { return buffer; }
+  };
 
 static int DvbOpen(const char *Name, int n, int Mode, bool ReportError = false)
 {
-  const char *FileName = DvbName(Name, n);
+  const char *FileName = *cDvbName(Name, n);
   int fd = open(FileName, Mode);
   if (fd < 0 && ReportError)
      LOG_ERROR_STR(FileName);
@@ -406,7 +409,7 @@ cDvbDevice::cDvbDevice(int n)
      dvb_frontend_info feinfo;
      if (ioctl(fd_frontend, FE_GET_INFO, &feinfo) >= 0) {
         frontendType = feinfo.type;
-        ciHandler = cCiHandler::CreateCiHandler(DvbName(DEV_DVB_CA, n));
+        ciHandler = cCiHandler::CreateCiHandler(*cDvbName(DEV_DVB_CA, n));
         dvbTuner = new cDvbTuner(fd_frontend, CardIndex(), frontendType, ciHandler);
         }
      else
@@ -449,7 +452,7 @@ bool cDvbDevice::Initialize(void)
   int i;
   for (i = 0; i < MAXDVBDEVICES; i++) {
       if (UseDevice(NextCardIndex())) {
-         if (Probe(DvbName(DEV_DVB_FRONTEND, i))) {
+         if (Probe(*cDvbName(DEV_DVB_FRONTEND, i))) {
             new cDvbDevice(i);
             found++;
             }
@@ -659,7 +662,7 @@ bool cDvbDevice::SetPid(cPidHandle *Handle, int Type, bool On)
 
 int cDvbDevice::OpenFilter(u_short Pid, u_char Tid, u_char Mask)
 {
-  const char *FileName = DvbName(DEV_DVB_DEMUX, CardIndex());
+  const char *FileName = *cDvbName(DEV_DVB_DEMUX, CardIndex());
   int f = open(FileName, O_RDWR | O_NONBLOCK);
   if (f >= 0) {
      dmx_sct_filter_params sctFilterParams;