Protect device enumeration in the router with a mutex

3 files changed, 19 insertions, 0 deletions

diff --git a/router/alc.c b/router/alc.c
index 17ba7013..0fb9cf4e 100644
--- a/router/alc.c
+++ b/router/alc.c
@@ -345,6 +345,7 @@ ALC_API ALCdevice* ALC_APIENTRY alcOpenDevice(const ALCchar *devicename)
         devicename = NULL;
     if(devicename)
     {
+        almtx_lock(&EnumerationLock);
         if(!DevicesList.Names)
             (void)alcGetString(NULL, ALC_DEVICE_SPECIFIER);
         idx = GetDriverIndexForName(&DevicesList, devicename);
@@ -356,9 +357,11 @@ ALC_API ALCdevice* ALC_APIENTRY alcOpenDevice(const ALCchar *devicename)
             if(idx < 0)
             {
                 ATOMIC_STORE_SEQ(&LastError, ALC_INVALID_VALUE);
+                almtx_unlock(&EnumerationLock);
                 return NULL;
             }
         }
+        almtx_unlock(&EnumerationLock);
     }
 
     device = DriverList[idx].alcOpenDevice(devicename);
@@ -624,6 +627,7 @@ ALC_API const ALCchar* ALC_APIENTRY alcGetString(ALCdevice *device, ALCenum para
         return alcExtensionList;
 
     case ALC_DEVICE_SPECIFIER:
+        almtx_lock(&EnumerationLock);
         ClearDeviceList(&DevicesList);
         for(i = 0;i < DriverListSize;i++)
         {
@@ -634,9 +638,11 @@ ALC_API const ALCchar* ALC_APIENTRY alcGetString(ALCdevice *device, ALCenum para
                     DriverList[i].alcGetString(NULL, ALC_DEVICE_SPECIFIER), i
                 );
         }
+        almtx_unlock(&EnumerationLock);
         return DevicesList.Names;
 
     case ALC_ALL_DEVICES_SPECIFIER:
+        almtx_lock(&EnumerationLock);
         ClearDeviceList(&AllDevicesList);
         for(i = 0;i < DriverListSize;i++)
         {
@@ -653,9 +659,11 @@ ALC_API const ALCchar* ALC_APIENTRY alcGetString(ALCdevice *device, ALCenum para
                     DriverList[i].alcGetString(NULL, ALC_DEVICE_SPECIFIER), i
                 );
         }
+        almtx_unlock(&EnumerationLock);
         return AllDevicesList.Names;
 
     case ALC_CAPTURE_DEVICE_SPECIFIER:
+        almtx_lock(&EnumerationLock);
         ClearDeviceList(&CaptureDevicesList);
         for(i = 0;i < DriverListSize;i++)
         {
@@ -665,6 +673,7 @@ ALC_API const ALCchar* ALC_APIENTRY alcGetString(ALCdevice *device, ALCenum para
                     DriverList[i].alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER), i
                 );
         }
+        almtx_unlock(&EnumerationLock);
         return CaptureDevicesList.Names;
 
     case ALC_DEFAULT_DEVICE_SPECIFIER:
@@ -745,14 +754,17 @@ ALC_API ALCdevice* ALC_APIENTRY alcCaptureOpenDevice(const ALCchar *devicename,
         devicename = NULL;
     if(devicename)
     {
+        almtx_lock(&EnumerationLock);
         if(!CaptureDevicesList.Names)
             (void)alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER);
         idx = GetDriverIndexForName(&CaptureDevicesList, devicename);
         if(idx < 0)
         {
             ATOMIC_STORE_SEQ(&LastError, ALC_INVALID_VALUE);
+            almtx_unlock(&EnumerationLock);
             return NULL;
         }
+        almtx_unlock(&EnumerationLock);
     }
 
     device = DriverList[idx].alcCaptureOpenDevice(devicename, frequency, format, buffersize);
diff --git a/router/router.c b/router/router.c
index 86189b78..4dfae314 100644
--- a/router/router.c
+++ b/router/router.c
@@ -15,6 +15,8 @@ DriverIface *DriverList = NULL;
 int DriverListSize = 0;
 static int DriverListSizeMax = 0;
 
+almtx_t EnumerationLock;
+
 static void LoadDriverList(void);
 
 
@@ -26,6 +28,7 @@ BOOL APIENTRY DllMain(HINSTANCE UNUSED(module), DWORD reason, void* UNUSED(reser
     {
         case DLL_PROCESS_ATTACH:
             LoadDriverList();
+            almtx_init(&EnumerationLock, almtx_recursive);
             break;
 
         case DLL_THREAD_ATTACH:
@@ -34,6 +37,7 @@ BOOL APIENTRY DllMain(HINSTANCE UNUSED(module), DWORD reason, void* UNUSED(reser
 
         case DLL_PROCESS_DETACH:
             ReleaseALC();
+            almtx_destroy(&EnumerationLock);
             for(i = 0;i < DriverListSize;i++)
             {
                 if(DriverList[i].Module)
diff --git a/router/router.h b/router/router.h
index 30401f88..78f7b6c0 100644
--- a/router/router.h
+++ b/router/router.h
@@ -9,6 +9,7 @@
 #include "AL/al.h"
 #include "atomic.h"
 #include "rwlock.h"
+#include "threads.h"
 
 
 #ifndef UNUSED
@@ -150,6 +151,8 @@ ALint RemovePtrIntMapKey(PtrIntMap *map, ALvoid *key);
 ALint LookupPtrIntMapKey(PtrIntMap *map, ALvoid *key);
 
 
+extern almtx_t EnumerationLock;
+
 void ReleaseALC(void);
 
 #endif /* ROUTER_ROUTER_H */