Never return null from CreateRingBuffer

Allocation failure would already throw a bad_alloc anyway, now a size overflow
throws an exception too.

alc/backends/alsa.cpp

@@ -981,10 +981,7 @@ void AlsaCapture::open(const ALCchar *name)
     hp = nullptr;
 
     if(needring)
-    {
         mRing = CreateRingBuffer(mDevice->BufferSize, mDevice->frameSizeFromFmt(), false);
-        if(!mRing) throw al::backend_exception{ALC_INVALID_VALUE, "Failed to create ring buffer"};
-    }
 
     mDevice->DeviceName = name;
     return;

alc/backends/coreaudio.cpp

@@ -570,7 +570,6 @@ void CoreAudioCapture::open(const ALCchar *name)
             mDevice->Frequency, Resampler::FastBSinc24);
 
     mRing = CreateRingBuffer(outputFrameCount, mFrameSize, false);
-    if(!mRing) throw al::backend_exception{ALC_INVALID_VALUE, "Failed to allocate ring buffer"};
 
     mDevice->DeviceName = name;
 }

alc/backends/dsound.cpp

@@ -743,10 +743,7 @@ void DSoundCapture::open(const ALCchar *name)
     if(SUCCEEDED(hr))
         mDSC->CreateCaptureBuffer(&DSCBDescription, &mDSCbuffer, nullptr);
     if(SUCCEEDED(hr))
-    {
          mRing = CreateRingBuffer(mDevice->BufferSize, InputType.Format.nBlockAlign, false);
-         if(!mRing) hr = DSERR_OUTOFMEMORY;
-    }
 
     if(FAILED(hr))
     {

alc/backends/jack.cpp

@@ -212,11 +212,7 @@ int JackPlayback::bufferSizeNotify(jack_nframes_t numframes)
 
     mRing = nullptr;
     mRing = CreateRingBuffer(bufsize, mDevice->frameSizeFromFmt(), true);
-    if(!mRing)
+
-    {
-        ERR("Failed to reallocate ringbuffer\n");
-        aluHandleDisconnect(mDevice, "Failed to reallocate %u-sample buffer", bufsize);
-    }
     return 0;
 }
 
@@ -407,11 +403,6 @@ bool JackPlayback::reset()
 
     mRing = nullptr;
     mRing = CreateRingBuffer(bufsize, mDevice->frameSizeFromFmt(), true);
-    if(!mRing)
-    {
-        ERR("Failed to allocate ringbuffer\n");
-        return false;
-    }
 
     SetDefaultChannelOrder(mDevice);
 

alc/backends/opensl.cpp

@@ -521,14 +521,7 @@ bool OpenSLPlayback::reset()
     if(SL_RESULT_SUCCESS == result)
     {
         const ALuint num_updates{mDevice->BufferSize / mDevice->UpdateSize};
-        try {
+        mRing = CreateRingBuffer(num_updates, mFrameSize*mDevice->UpdateSize, true);
-            mRing = CreateRingBuffer(num_updates, mFrameSize*mDevice->UpdateSize, true);
-        }
-        catch(std::exception& e) {
-            ERR("Failed allocating ring buffer %ux%ux%u: %s\n", mDevice->UpdateSize,
-                num_updates, mFrameSize, e.what());
-            result = SL_RESULT_MEMORY_FAILURE;
-        }
     }
 
     if(SL_RESULT_SUCCESS != result)
@@ -703,16 +696,10 @@ void OpenSLCapture::open(const ALCchar* name)
             mDevice->Frequency/100*5)};
         ALuint num_updates{(length+update_len-1) / update_len};
 
-        try {
+        mRing = CreateRingBuffer(num_updates, update_len*mFrameSize, false);
-            mRing = CreateRingBuffer(num_updates, update_len*mFrameSize, false);
 
-            mDevice->UpdateSize = update_len;
+        mDevice->UpdateSize = update_len;
-            mDevice->BufferSize = static_cast<ALuint>(mRing->writeSpace() * update_len);
+        mDevice->BufferSize = static_cast<ALuint>(mRing->writeSpace() * update_len);
-        }
-        catch(std::exception& e) {
-            ERR("Failed to allocate ring buffer: %s\n", e.what());
-            result = SL_RESULT_MEMORY_FAILURE;
-        }
     }
     if(SL_RESULT_SUCCESS == result)
     {

alc/backends/oss.cpp

@@ -612,7 +612,6 @@ void OSScapture::open(const ALCchar *name)
             ossFormat};
 
     mRing = CreateRingBuffer(mDevice->BufferSize, frameSize, false);
-    if(!mRing) throw al::backend_exception{ALC_INVALID_VALUE, "Failed to create ring buffer"};
 
     mDevice->DeviceName = name;
 }

alc/backends/portaudio.cpp

@@ -286,7 +286,6 @@ void PortCapture::open(const ALCchar *name)
     ALuint frame_size{mDevice->frameSizeFromFmt()};
 
     mRing = CreateRingBuffer(samples, frame_size, false);
-    if(!mRing) throw al::backend_exception{ALC_INVALID_VALUE, "Failed to create ring buffer"};
 
     auto devidopt = ConfigValueInt(nullptr, "port", "capture");
     if(devidopt && *devidopt >= 0) mParams.device = *devidopt;

alc/backends/sndio.cpp

@@ -393,7 +393,6 @@ void SndioCapture::open(const ALCchar *name)
             mDevice->Frequency, par.sig?'s':'u', par.bits, par.rchan, par.rate};
 
     mRing = CreateRingBuffer(mDevice->BufferSize, par.bps*par.rchan, false);
-    if(!mRing) throw al::backend_exception{ALC_OUT_OF_MEMORY, "Failed to allocate ring buffer"};
 
     SetDefaultChannelOrder(mDevice);
 

alc/backends/wasapi.cpp

@@ -1601,11 +1601,6 @@ HRESULT WasapiCapture::resetProxy()
 
     buffer_len = maxu(mDevice->BufferSize, buffer_len);
     mRing = CreateRingBuffer(buffer_len, mDevice->frameSizeFromFmt(), false);
-    if(!mRing)
-    {
-        ERR("Failed to allocate capture ring buffer\n");
-        return E_OUTOFMEMORY;
-    }
 
     hr = mClient->SetEventHandle(mNotifyEvent);
     if(FAILED(hr))

alc/backends/winmm.cpp

@@ -519,7 +519,6 @@ void WinMMCapture::open(const ALCchar *name)
     CapturedDataSize = static_cast<ALuint>(maxz(CapturedDataSize, BufferSize*mWaveBuffer.size()));
 
     mRing = CreateRingBuffer(CapturedDataSize, mFormat.nBlockAlign, false);
-    if(!mRing) throw al::backend_exception{ALC_INVALID_VALUE, "Could not create ring buffer"};
 
     al_free(mWaveBuffer[0].lpData);
     mWaveBuffer[0] = WAVEHDR{};

alc/ringbuffer.cpp

@@ -25,6 +25,7 @@
 #include <algorithm>
 #include <climits>
 #include <cstdint>
+#include <stdexcept>
 
 #include "almalloc.h"
 
@@ -45,7 +46,8 @@ RingBufferPtr CreateRingBuffer(size_t sz, size_t elem_sz, int limit_writes)
 #endif
     }
     ++power_of_two;
-    if(power_of_two < sz) return nullptr;
+    if(power_of_two <= sz || power_of_two > std::numeric_limits<size_t>::max()/elem_sz)
+        throw std::overflow_error{"Ring buffer size overflow"};
 
     const size_t bufbytes{power_of_two * elem_sz};
     RingBufferPtr rb{new (FamCount{bufbytes}) RingBuffer{bufbytes}};