Add volatile/mutexes around download thread

src/bk_download.cpp

@@ -19,6 +19,7 @@
 #include <set>
 #include <string>
 #include <thread>
+#include <mutex>
 #include <sys/file.h>
 #include <photon/common/alog.h>
 #include <photon/common/alog-stdstring.h>
@@ -53,6 +54,7 @@ bool check_downloaded(const std::string &dir) {
     return false;
 }
 
+static std::mutex lock_files_mutex;
 static std::set<std::string> lock_files;
 
 void BkDownload::switch_to_local_file() {
@@ -188,6 +190,7 @@ bool BkDownload::download() {
 }
 
 bool BkDownload::lock_file() {
+    std::lock_guard<std::mutex> lock(lock_files_mutex);
     if (lock_files.find(dir) != lock_files.end()) {
         LOG_WARN("failed to lock download path:`", dir);
         return false;
@@ -197,6 +200,7 @@ bool BkDownload::lock_file() {
 }
 
 void BkDownload::unlock_file() {
+    std::lock_guard<std::mutex> lock(lock_files_mutex);
     lock_files.erase(dir);
 }
 
@@ -337,7 +341,7 @@ bool BkDownload::download_blob() {
     return true;
 }
 
-void bk_download_proc(std::list<BKDL::BkDownload *> &dl_list, uint64_t delay_sec, int &running) {
+void bk_download_proc(std::list<BKDL::BkDownload *> &dl_list, uint64_t delay_sec, volatile int &running) {
     auto tracer = overlaybd_otel::get_tracer("overlaybd");
     auto span = tracer->StartSpan("background_download_process");
     auto scope = tracer->WithActiveSpan(span);

src/bk_download.h

@@ -17,6 +17,7 @@
 #include <list>
 #include <string>
 #include <cstdint>
+#include <atomic>
 #include <photon/fs/filesystem.h>
 #include "overlaybd/otel/tracer_common.h"
 
@@ -45,7 +46,7 @@ class BkDownload {
     }
     BkDownload(ISwitchFile *sw_file, photon::fs::IFile *src_file, size_t file_size,
                const std::string &dir, const std::string &digest, const std::string &url,
-               int &running, int32_t limit_MB_ps, int32_t try_cnt, uint32_t bs)
+               volatile int &running, int32_t limit_MB_ps, int32_t try_cnt, uint32_t bs)
         : dir(dir), try_cnt(try_cnt), sw_file(sw_file), src_file(src_file),
           file_size(file_size), digest(digest), url(url), running(running),
           limit_MB_ps(limit_MB_ps), block_size(bs) {
@@ -61,12 +62,12 @@ class BkDownload {
     size_t file_size;
     std::string digest;
     std::string url;
-    int &running;
+    volatile int &running;
     int32_t limit_MB_ps;
     uint32_t block_size;
     bool force_download = false;
 };
 
-void bk_download_proc(std::list<BKDL::BkDownload *> &, uint64_t, int &);
+void bk_download_proc(std::list<BKDL::BkDownload *> &, uint64_t, volatile int &);
 
 } // namespace BKDL

src/image_file.h

@@ -99,7 +99,7 @@ class ImageFile : public photon::fs::ForwardFile {
     int open_lower_layer(IFile *&file, ImageConfigNS::LayerConfig &layer, int index);
 
     std::string m_exception;
-    int m_status = 0; // 0: not started, 1: running, -1 exit
+    volatile int m_status = 0; // 0: not started, 1: running, -1 exit
 
     size_t size;
     uint64_t num_lbas;