fixes #1409 reader/writer lock desired

This provides the initial implementation, and converts the
transport lookup routines to use it.  This is probably of limited
performance benefit, but rwlock's may be useful in further future work.

1 files changed, 55 insertions, 19 deletions

diff --git a/src/platform/windows/win_thread.c b/src/platform/windows/win_thread.c
index 7cc87eb3..c069d3c9 100644
--- a/src/platform/windows/win_thread.c
+++ b/src/platform/windows/win_thread.c
@@ -77,6 +77,42 @@ nni_plat_mtx_unlock(nni_plat_mtx *mtx)
 }
 
 void
+nni_rwlock_init(nni_rwlock *rwl)
+{
+	InitializeSRWLock(&rwl->rwl);
+}
+
+void
+nni_rwlock_fini(nni_rwlock *rwl)
+{
+	rwl->exclusive = FALSE;
+}
+
+void
+nni_rwlock_rdlock(nni_rwlock *rwl)
+{
+	AcquireSRWLockShared(&rwl->rwl);
+}
+
+void
+nni_rwlock_wrlock(nni_rwlock *rwl)
+{
+	AcquireSRWLockExclusive(&rwl->rwl);
+	rwl->exclusive = TRUE;
+}
+
+void
+nni_rwlock_unlock(nni_rwlock *rwl)
+{
+	if (rwl->exclusive) {
+		rwl->exclusive = FALSE;
+		ReleaseSRWLockExclusive(&rwl->rwl);
+	} else {
+		ReleaseSRWLockShared(&rwl->rwl);
+	}
+}
+
+void
 nni_plat_cv_init(nni_plat_cv *cv, nni_plat_mtx *mtx)
 {
 	InitializeConditionVariable(&cv->cv);
@@ -112,7 +148,7 @@ nni_plat_cv_until(nni_plat_cv *cv, nni_time until)
 	if (now > until) {
 		msec = 0;
 	} else {
-		msec = (DWORD)(until - now);
+		msec = (DWORD) (until - now);
 	}
 
 	ok = SleepConditionVariableSRW(&cv->cv, cv->srl, msec, 0);
@@ -178,7 +214,7 @@ uint64_t
 nni_atomic_get64(nni_atomic_u64 *v)
 {
 
-	return ((uint64_t)(InterlockedExchangeAdd64(&v->v, 0)));
+	return ((uint64_t) (InterlockedExchangeAdd64(&v->v, 0)));
 }
 
 void
@@ -190,7 +226,7 @@ nni_atomic_set64(nni_atomic_u64 *v, uint64_t u)
 uint64_t
 nni_atomic_swap64(nni_atomic_u64 *v, uint64_t u)
 {
-	return ((uint64_t)(InterlockedExchange64(&v->v, (LONGLONG) u)));
+	return ((uint64_t) (InterlockedExchange64(&v->v, (LONGLONG) u)));
 }
 
 void
@@ -213,9 +249,9 @@ uint64_t
 nni_atomic_dec64_nv(nni_atomic_u64 *v)
 {
 #ifdef _WIN64
-	return ((uint64_t)(InterlockedDecrementRelease64(&v->v)));
+	return ((uint64_t) (InterlockedDecrementRelease64(&v->v)));
 #else
-	return ((uint64_t)(InterlockedDecrement64(&v->v)));
+	return ((uint64_t) (InterlockedDecrement64(&v->v)));
 #endif
 }
 
@@ -331,9 +367,9 @@ void
 nni_plat_thr_set_name(nni_plat_thr *thr, const char *name)
 {
 	if (set_thread_desc != NULL) {
-                wchar_t *wcs;
-                size_t len;
-		HANDLE h;
+		wchar_t *wcs;
+		size_t   len;
+		HANDLE   h;
 
 		if (thr == NULL) {
 			h = GetCurrentThread();
@@ -341,7 +377,7 @@ nni_plat_thr_set_name(nni_plat_thr *thr, const char *name)
 			h = thr->handle;
 		}
 
-                len = strlen(name) + 1;
+		len = strlen(name) + 1;
 		if ((wcs = nni_alloc(len * 2)) == NULL) {
 			return;
 		}
@@ -372,18 +408,18 @@ nni_plat_init(int (*helper)(void))
 		return (0); // fast path
 	}
 
-
-        AcquireSRWLockExclusive(&lock);
+	AcquireSRWLockExclusive(&lock);
 
 	if (!plat_inited) {
-                // Let's look up the function to set thread descriptions.
-                hKernel32 = LoadLibrary(TEXT("kernel32.dll"));
-                if (hKernel32 != NULL) {
-                        set_thread_desc = (pfnSetThreadDescription)
-                            GetProcAddress(hKernel32, "SetThreadDescription");
-                }
-
-                if (((rv = nni_win_io_sysinit()) != 0) ||
+		// Let's look up the function to set thread descriptions.
+		hKernel32 = LoadLibrary(TEXT("kernel32.dll"));
+		if (hKernel32 != NULL) {
+			set_thread_desc =
+			    (pfnSetThreadDescription) GetProcAddress(
+			        hKernel32, "SetThreadDescription");
+		}
+
+		if (((rv = nni_win_io_sysinit()) != 0) ||
 		    ((rv = nni_win_ipc_sysinit()) != 0) ||
 		    ((rv = nni_win_tcp_sysinit()) != 0) ||
 		    ((rv = nni_win_udp_sysinit()) != 0) ||