From 771edfa5b304816baacdd4fe470e2fe5ec8561f9 Mon Sep 17 00:00:00 2001 From: Wagner Bruna Date: Sat, 7 Feb 2026 08:56:24 -0300 Subject: [PATCH 1/2] feat: support for canceling the ongoing generation --- include/stable-diffusion.h | 9 +++++++ src/stable-diffusion.cpp | 49 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/include/stable-diffusion.h b/include/stable-diffusion.h index cb966d7e8..8f8f6ade2 100644 --- a/include/stable-diffusion.h +++ b/include/stable-diffusion.h @@ -372,6 +372,15 @@ SD_API void sd_img_gen_params_init(sd_img_gen_params_t* sd_img_gen_params); SD_API char* sd_img_gen_params_to_str(const sd_img_gen_params_t* sd_img_gen_params); SD_API sd_image_t* generate_image(sd_ctx_t* sd_ctx, const sd_img_gen_params_t* sd_img_gen_params); +enum sd_cancel_mode_t +{ + SD_CANCEL_ALL, + SD_CANCEL_NEW_LATENTS, + SD_CANCEL_RESET +}; + +SD_API void sd_cancel_generation(sd_ctx_t* sd_ctx, enum sd_cancel_mode_t mode); + SD_API void sd_vid_gen_params_init(sd_vid_gen_params_t* sd_vid_gen_params); SD_API sd_image_t* generate_video(sd_ctx_t* sd_ctx, const sd_vid_gen_params_t* sd_vid_gen_params, int* num_frames_out); diff --git a/src/stable-diffusion.cpp b/src/stable-diffusion.cpp index c0ee1182d..19a390140 100644 --- a/src/stable-diffusion.cpp +++ b/src/stable-diffusion.cpp @@ -23,6 +23,8 @@ #include "latent-preview.h" #include "name_conversion.h" +#include + const char* model_version_to_str[] = { "SD 1.x", "SD 1.x Inpaint", @@ -98,6 +100,9 @@ void suppress_pp(int step, int steps, float time, void* data) { /*=============================================== StableDiffusionGGML ================================================*/ +static_assert(std::atomic::is_always_lock_free, + "sd_cancel_mode_t must be lock-free"); + class StableDiffusionGGML { public: ggml_backend_t backend = nullptr; // general backend @@ -146,6 +151,8 @@ class StableDiffusionGGML { std::shared_ptr denoiser = std::make_shared(); + std::atomic cancellation_flag; + StableDiffusionGGML() = default; ~StableDiffusionGGML() { @@ -161,6 +168,18 @@ class StableDiffusionGGML { ggml_backend_free(backend); } + void set_cancel_flag(enum sd_cancel_mode_t flag) { + cancellation_flag.store(flag, std::memory_order_release); + } + + void reset_cancel_flag() { + set_cancel_flag(SD_CANCEL_RESET); + } + + enum sd_cancel_mode_t get_cancel_flag() { + return cancellation_flag.load(std::memory_order_acquire); + } + void init_backend() { #ifdef SD_USE_CUDA LOG_DEBUG("Using CUDA backend"); @@ -1847,6 +1866,12 @@ class StableDiffusionGGML { } auto denoise = [&](ggml_tensor* input, float sigma, int step) -> ggml_tensor* { + enum sd_cancel_mode_t cancel_flag = get_cancel_flag(); + if (cancel_flag != SD_CANCEL_RESET) { + LOG_DEBUG("cancelling latent decodings"); + return nullptr; + } + auto sd_preview_cb = sd_get_preview_callback(); auto sd_preview_cb_data = sd_get_preview_callback_data(); auto sd_preview_mode = sd_get_preview_mode(); @@ -3385,6 +3410,12 @@ sd_image_t* generate_image_internal(sd_ctx_t* sd_ctx, img_cond = SDCondition(uncond.c_crossattn, uncond.c_vector, cond.c_concat); } for (int b = 0; b < batch_count; b++) { + + if (sd_ctx->sd->get_cancel_flag() != SD_CANCEL_RESET) { + LOG_ERROR("cancelling generation"); + break; + } + int64_t sampling_start = ggml_time_ms(); int64_t cur_seed = seed + b; LOG_INFO("generating image: %i/%i - seed %" PRId64, b + 1, batch_count, cur_seed); @@ -3446,6 +3477,12 @@ sd_image_t* generate_image_internal(sd_ctx_t* sd_ctx, LOG_INFO("decoding %zu latents", final_latents.size()); std::vector decoded_images; // collect decoded images for (size_t i = 0; i < final_latents.size(); i++) { + + if (sd_ctx->sd->get_cancel_flag() == SD_CANCEL_ALL) { + LOG_ERROR("cancelling latent decodings"); + break; + } + t1 = ggml_time_ms(); struct ggml_tensor* img = sd_ctx->sd->decode_first_stage(work_ctx, final_latents[i] /* x_0 */); // print_ggml_tensor(img); @@ -3482,6 +3519,16 @@ sd_image_t* generate_image_internal(sd_ctx_t* sd_ctx, return result_images; } +void sd_cancel_generation(sd_ctx_t* sd_ctx, enum sd_cancel_mode_t mode) +{ + if (sd_ctx && sd_ctx->sd) { + if (mode < SD_CANCEL_ALL || mode > SD_CANCEL_RESET) { + mode = SD_CANCEL_ALL; + } + sd_ctx->sd->set_cancel_flag(mode); + } +} + sd_image_t* generate_image(sd_ctx_t* sd_ctx, const sd_img_gen_params_t* sd_img_gen_params) { sd_ctx->sd->vae_tiling_params = sd_img_gen_params->vae_tiling_params; int width = sd_img_gen_params->width; @@ -3504,6 +3551,8 @@ sd_image_t* generate_image(sd_ctx_t* sd_ctx, const sd_img_gen_params_t* sd_img_g return nullptr; } + sd_ctx->sd->reset_cancel_flag(); + struct ggml_init_params params; params.mem_size = static_cast(1024 * 1024) * 1024; // 1G params.mem_buffer = nullptr; From 2f7bae7cb5c82a83fd5597dffb8be310d2a9b3f2 Mon Sep 17 00:00:00 2001 From: Wagner Bruna Date: Thu, 12 Feb 2026 17:44:26 -0300 Subject: [PATCH 2/2] feat(server): cancel current generation on client disconnect Co-authored-by: donington --- examples/server/main.cpp | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/examples/server/main.cpp b/examples/server/main.cpp index 0fb10c7a3..5e6377978 100644 --- a/examples/server/main.cpp +++ b/examples/server/main.cpp @@ -2,6 +2,7 @@ #include #include #include +#include #include #include #include @@ -365,6 +366,18 @@ int main(int argc, const char** argv) { return httplib::Server::HandlerResponse::Unhandled; }); + auto wait_for_generation = [](std::future& ft, sd_ctx_t* sd_ctx, const httplib::Request& req) { + std::future_status ft_status; + do { + if (!ft.valid()) + break; + ft_status = ft.wait_for(std::chrono::milliseconds(1000)); + if (req.is_connection_closed()) { + sd_cancel_generation(sd_ctx, SD_CANCEL_ALL); + } + } while (ft_status != std::future_status::ready); + }; + // root svr.Get("/", [&](const httplib::Request&, httplib::Response& res) { if (!svr_params.serve_html_path.empty()) { @@ -507,11 +520,13 @@ int main(int argc, const char** argv) { sd_image_t* results = nullptr; int num_results = 0; - { + std::future ft = std::async(std::launch::async, [&]() { std::lock_guard lock(sd_ctx_mutex); results = generate_image(sd_ctx, &img_gen_params); num_results = gen_params.batch_count; - } + }); + + wait_for_generation(ft, sd_ctx, req); for (int i = 0; i < num_results; i++) { if (results[i].data == nullptr) { @@ -748,11 +763,13 @@ int main(int argc, const char** argv) { sd_image_t* results = nullptr; int num_results = 0; - { + std::future ft = std::async(std::launch::async, [&]() { std::lock_guard lock(sd_ctx_mutex); results = generate_image(sd_ctx, &img_gen_params); num_results = gen_params.batch_count; - } + }); + + wait_for_generation(ft, sd_ctx, req); json out; out["created"] = static_cast(std::time(nullptr)); @@ -1062,11 +1079,13 @@ int main(int argc, const char** argv) { sd_image_t* results = nullptr; int num_results = 0; - { + std::future ft = std::async(std::launch::async, [&]() { std::lock_guard lock(sd_ctx_mutex); results = generate_image(sd_ctx, &img_gen_params); num_results = gen_params.batch_count; - } + }); + + wait_for_generation(ft, sd_ctx, req); json out; out["images"] = json::array();