048acb509c
Fixed race conditions and memory safety issues in the progress example by using C11 atomic operations for proper thread synchronization. Changes: - Changed percentage from double to _Atomic double - Use atomic_store_explicit() with memory_order_release when writing - Use atomic_load_explicit() with memory_order_acquire when reading - Removed unsafe pointer passing via async.data This ensures proper memory synchronization between the worker thread and async callback, preventing data races and dangling pointer issues. Fixes #4386 Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#include <stdatomic.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <uv.h>
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uv_loop_t *loop;
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uv_async_t async;
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_Atomic double percentage;
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void fake_download(uv_work_t *req) {
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int size = *((int*) req->data);
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int downloaded = 0;
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double pct;
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while (downloaded < size) {
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pct = downloaded * 100.0 / size;
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atomic_store_explicit(&percentage, pct, memory_order_release);
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uv_async_send(&async);
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sleep(1);
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downloaded += (200+random())%1000; // can only download max 1000bytes/sec,
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// but at least a 200;
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}
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// Ensure final 100% progress update is sent
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pct = 100.0;
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atomic_store_explicit(&percentage, pct, memory_order_release);
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uv_async_send(&async);
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}
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void after(uv_work_t *req, int status) {
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fprintf(stderr, "Download complete\n");
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uv_close((uv_handle_t*) &async, NULL);
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}
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void print_progress(uv_async_t *handle) {
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double pct = atomic_load_explicit(&percentage, memory_order_acquire);
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fprintf(stderr, "Downloaded %.2f%%\n", pct);
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}
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int main() {
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loop = uv_default_loop();
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uv_work_t req;
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int size = 10240;
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req.data = (void*) &size;
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uv_async_init(loop, &async, print_progress);
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uv_queue_work(loop, &req, fake_download, after);
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return uv_run(loop, UV_RUN_DEFAULT);
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}
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