diff options
| author | Laszlo Agocs <laszlo.agocs@qt.io> | 2023-03-17 18:39:24 +0100 |
|---|---|---|
| committer | Laszlo Agocs <laszlo.agocs@qt.io> | 2023-03-21 11:55:47 +0100 |
| commit | c0182c7817cb326d1b02ff8e7c75ed011d82d39f (patch) | |
| tree | bd9748a3eff4765c6f72a4ad3427961805ae889f /src | |
| parent | 2305f8af9f24cd5a71e1eb7129b518ad621a1770 (diff) | |
rhi: metal: Share semaphore code within the backend
Change-Id: I5b52cb8ccac303c4532651553101f381568eba2d
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
Diffstat (limited to 'src')
| -rw-r--r-- | src/gui/rhi/qrhimetal.mm | 58 | ||||
| -rw-r--r-- | src/gui/rhi/qrhimetal_p_p.h | 1 |
2 files changed, 34 insertions, 25 deletions
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm index 89c0271e7a6..e892fad3f33 100644 --- a/src/gui/rhi/qrhimetal.mm +++ b/src/gui/rhi/qrhimetal.mm @@ -2237,23 +2237,25 @@ QRhi::FrameOpResult QRhiMetal::beginFrame(QRhiSwapChain *swapChain, QRhi::BeginF Q_UNUSED(flags); QMetalSwapChain *swapChainD = QRHI_RES(QMetalSwapChain, swapChain); + currentSwapChain = swapChainD; + currentFrameSlot = swapChainD->currentFrameSlot; - // This is a bit messed up since for this swapchain we want to wait for the - // commands+present to complete, while for others just for the commands - // (for this same frame slot) but not sure how to do that in a sane way so - // wait for full cb completion for now. + // If we are too far ahead, block. This is also what ensures that any + // resource used in the previous frame for this slot is now not in use + // anymore by the GPU. + dispatch_semaphore_wait(swapChainD->d->sem[currentFrameSlot], DISPATCH_TIME_FOREVER); + + // Do this also for any other swapchain's commands with the same frame slot + // While this reduces concurrency, it keeps resource usage safe: swapchain + // A starting its frame 0, followed by swapchain B starting its own frame 0 + // will make B wait for A's frame 0 commands, so if a resource is written + // in B's frame or when B checks for pending resource releases, that won't + // mess up A's in-flight commands (as they are not in flight anymore). for (QMetalSwapChain *sc : std::as_const(swapchains)) { - dispatch_semaphore_t sem = sc->d->sem[swapChainD->currentFrameSlot]; - dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER); if (sc != swapChainD) - dispatch_semaphore_signal(sem); + sc->waitUntilCompleted(currentFrameSlot); // wait+signal } - currentSwapChain = swapChainD; - currentFrameSlot = swapChainD->currentFrameSlot; - if (swapChainD->ds) - swapChainD->ds->lastActiveFrameSlot = currentFrameSlot; - [d->captureScope beginScope]; // Do not let the command buffer mess with the refcount of objects. We do @@ -2274,6 +2276,9 @@ QRhi::FrameOpResult QRhiMetal::beginFrame(QRhiSwapChain *swapChain, QRhi::BeginF swapChainD->rtWrapper.d->fb.hasStencil = swapChainD->ds ? true : false; swapChainD->rtWrapper.d->fb.depthNeedsStore = false; + if (swapChainD->ds) + swapChainD->ds->lastActiveFrameSlot = currentFrameSlot; + executeDeferredReleases(); swapChainD->cbWrapper.resetState(); finishActiveReadbacks(); @@ -2335,14 +2340,9 @@ QRhi::FrameOpResult QRhiMetal::beginOffscreenFrame(QRhiCommandBuffer **cb, QRhi: Q_UNUSED(flags); currentFrameSlot = (currentFrameSlot + 1) % QMTL_FRAMES_IN_FLIGHT; - for (QMetalSwapChain *sc : std::as_const(swapchains)) { - // wait+signal is the general pattern to ensure the commands for a - // given frame slot have completed (if sem is 1, we go 0 then 1; if - // sem is 0 we go -1, block, completion increments to 0, then us to 1) - dispatch_semaphore_t sem = sc->d->sem[currentFrameSlot]; - dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER); - dispatch_semaphore_signal(sem); - } + + for (QMetalSwapChain *sc : std::as_const(swapchains)) + sc->waitUntilCompleted(currentFrameSlot); d->ofr.active = true; *cb = &d->ofr.cbWrapper; @@ -2395,9 +2395,7 @@ QRhi::FrameOpResult QRhiMetal::finish() // beginFrame decremented sem already and going to be signaled by endFrame continue; } - dispatch_semaphore_t sem = sc->d->sem[i]; - dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER); - dispatch_semaphore_signal(sem); + sc->waitUntilCompleted(i); } } @@ -5964,8 +5962,7 @@ void QMetalSwapChain::destroy() for (int i = 0; i < QMTL_FRAMES_IN_FLIGHT; ++i) { if (d->sem[i]) { // the semaphores cannot be released if they do not have the initial value - dispatch_semaphore_wait(d->sem[i], DISPATCH_TIME_FOREVER); - dispatch_semaphore_signal(d->sem[i]); + waitUntilCompleted(i); dispatch_release(d->sem[i]); d->sem[i] = nullptr; @@ -6084,6 +6081,17 @@ void QMetalSwapChain::chooseFormats() d->rhiColorFormat = QRhiTexture::BGRA8; } +void QMetalSwapChain::waitUntilCompleted(int slot) +{ + // wait+signal is the general pattern to ensure the commands for a + // given frame slot have completed (if sem is 1, we go 0 then 1; if + // sem is 0 we go -1, block, completion increments to 0, then us to 1) + + dispatch_semaphore_t sem = d->sem[slot]; + dispatch_semaphore_wait(sem, DISPATCH_TIME_FOREVER); + dispatch_semaphore_signal(sem); +} + bool QMetalSwapChain::createOrResize() { Q_ASSERT(m_window); diff --git a/src/gui/rhi/qrhimetal_p_p.h b/src/gui/rhi/qrhimetal_p_p.h index ff57e84ae9c..c76a29b0a8c 100644 --- a/src/gui/rhi/qrhimetal_p_p.h +++ b/src/gui/rhi/qrhimetal_p_p.h @@ -308,6 +308,7 @@ struct QMetalSwapChain : public QRhiSwapChain virtual QRhiSwapChainHdrInfo hdrInfo() override; void chooseFormats(); + void waitUntilCompleted(int slot); QWindow *window = nullptr; QSize pixelSize; |