node-fibers issue #158

patch.diff

diff --git a/src/coroutine.cc b/src/coroutine.cc
index f2a0d3d..64bf201 100644
--- a/src/coroutine.cc
+++ b/src/coroutine.cc
@@ -20,9 +20,10 @@
 using namespace std;
 
 const size_t v8_tls_keys = 3;
-static pthread_key_t floor_thread_key = 0;
-static pthread_key_t ceil_thread_key = 0;
 static pthread_key_t coro_thread_key = 0;
+static pthread_key_t isolate_key = 0;
+static pthread_key_t thread_id_key = 0;
+static pthread_key_t thread_data_key = 0;
 
 static size_t stack_size = 0;
 static size_t coroutines_created_ = 0;
@@ -40,15 +41,38 @@ static DWORD __stdcall find_thread_id_key(LPVOID arg)
        assert(isolate != NULL);
        v8::Locker locker(isolate);
        isolate->Enter();
-       floor_thread_key = 0x7777;
-       for (pthread_key_t ii = coro_thread_key - 1; ii >= (coro_thread_key >= 20 ? coro_thread_key - 20 : 0); --ii) {
-               if (pthread_getspecific(ii) == isolate) {
-                       floor_thread_key = ii;
-                       break;
+       size_t thread_id = v8::V8::GetCurrentThreadId();
+       for (pthread_key_t ii = (coro_thread_key >= 20 ? coro_thread_key - 20 : 0); ii < coro_thread_key; ++ii) {
+               void* tls = pthread_getspecific(ii);
+               if (!isolate_key) {
+                       if (tls == isolate) {
+                               isolate_key = ii;
+                       }
+               } else if (!thread_id_key) {
+                       if ((size_t)tls == thread_id) {
+                               thread_id_key = ii;
+                       }
+               } else {
+#ifdef WINDOWS
+                       MEMORY_BASIC_INFORMATION mbi;
+                       if (!VirtualQueryEx(GetCurrentProcess(), tls, &mbi, sizeof(mbi))) {
+                               continue;
+                       }
+                       if (!mbi.State & MEM_COMMIT) {
+                               continue;
+                       }
+                       // TODO: Check pointer on other OS's? Windows is the only case I've seen so far that has
+                       // spooky gaps in the TLS key space
+#endif
+                       if (*(void**)tls == isolate) {
+                               // First member of per-thread data is the isolate
+                               assert(!thread_data_key);
+                               thread_data_key = ii;
+                               break;
+                       }
                }
        }
-       assert(floor_thread_key != 0x7777);
-       ceil_thread_key = floor_thread_key + v8_tls_keys - 1;
+       assert(thread_data_key);
        isolate->Exit();
        return NULL;
 }
@@ -160,13 +184,14 @@ void Coroutine::reset(entry_t* entry, void* arg) {
 void Coroutine::transfer(Coroutine& next) {
        assert(this != &next);
 #ifndef CORO_PTHREAD
-       {
-               for (pthread_key_t ii = floor_thread_key; ii <= ceil_thread_key; ++ii) {
-                       // Swap TLS keys with fiber locals
-                       fls_data[ii - floor_thread_key] = pthread_getspecific(ii);
-                       pthread_setspecific(ii, next.fls_data[ii - floor_thread_key]);
-               }
-       }
+       fls_data[0] = pthread_getspecific(isolate_key);
+       fls_data[1] = pthread_getspecific(thread_id_key);
+       fls_data[2] = pthread_getspecific(thread_data_key);
+
+       pthread_setspecific(isolate_key, next.fls_data[0]);
+       pthread_setspecific(thread_id_key, next.fls_data[1]);
+       pthread_setspecific(thread_data_key, next.fls_data[2]);
+
        pthread_setspecific(coro_thread_key, &next);
 #endif
        coro_transfer(&context, &next.context);