maybe fixe crash in file wather thread in 32-bit (fixes #4111)

sumatrapdfreader · May 13, 2024 · 4f40056 · 4f40056
1 parent 39e4ef1
commit 4f40056
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Showing 4 changed files with 18 additions and 13 deletions.
diff --git a/docs/manual.dat b/docs/manual.dat
diff --git a/src/utils/FileWatcher.cpp b/src/utils/FileWatcher.cpp
@@ -351,18 +351,6 @@ static DWORD WINAPI FileWatcherThread(void*) {
     return 0;
 }
 
-static void StartFileThreadIfNecessary() {
-    if (g_threadHandle) {
-        return;
-    }
-    logf("StartFileThreadIfNecessary: starting a thread\n");
-    InitializeCriticalSection(&g_threadCritSec);
-    g_threadControlHandle = CreateEvent(nullptr, TRUE, FALSE, nullptr);
-
-    g_threadHandle = CreateThread(nullptr, 0, FileWatcherThread, nullptr, 0, &g_threadId);
-    SetThreadName("FileWatcherThread", g_threadId);
-}
-
 static WatchedDir* FindExistingWatchedDir(const char* dirPath) {
     for (WatchedDir* wd = g_watchedDirs; wd; wd = wd->next) {
         // TODO: normalize dirPath?
@@ -468,8 +456,20 @@ WatchedFile* FileWatcherSubscribe(const char* path, const std::function<void()>&
         logf("FileWatcherSubscribe: path='%s' doesn't exist\n", path);
         return nullptr;
     }
+    if (IsProcess32()) {
+        // https://github.com/sumatrapdfreader/sumatrapdf/issues/4111
+        logf("FileWatcherSubscribe: not starting a file watcher thread due to 32-bit miscompilation\n");
+        return nullptr;
+    }
 
-    StartFileThreadIfNecessary();
+    if (!g_threadHandle) {
+        logf("StartFileThreadIfNecessary: starting a thread\n");
+        InitializeCriticalSection(&g_threadCritSec);
+        g_threadControlHandle = CreateEvent(nullptr, TRUE, FALSE, nullptr);
+
+        g_threadHandle = CreateThread(nullptr, 0, FileWatcherThread, nullptr, 0, &g_threadId);
+        SetThreadName("FileWatcherThread", g_threadId);
+    }
 
     ScopedCritSec cs(&g_threadCritSec);
     return NewWatchedFile(path, onFileChangedCb);

diff --git a/src/utils/WinUtil.cpp b/src/utils/WinUtil.cpp
@@ -284,6 +284,10 @@ bool IsProcess64() {
     return 8 == sizeof(void*);
 }
 
+bool IsProcess32() {
+    return 4 == sizeof(void*);
+}
+
 // return true if running on a 64-bit OS
 bool IsOs64() {
     // 64-bit processes can only run on a 64-bit OS,

diff --git a/src/utils/WinUtil.h b/src/utils/WinUtil.h
@@ -33,6 +33,7 @@ void MoveWindow(HWND hwnd, RECT* r);
 
 bool IsOs64();
 bool IsProcess64();
+bool IsProcess32();
 bool IsArmBuild();
 bool IsRunningInWow64();
 bool IsProcessAndOsArchSame();