Win32: added WSAPoll() support.

WSAPoll() is only available with Windows Vista and newer (and only
available during compilation if _WIN32_WINNT >= 0x0600).  To make
sure the code works with Windows XP, we do not redefine _WIN32_WINNT,
but instead load WSAPoll() dynamically if it is not available during
compilation.

Also, sockets are not guaranteed to be small integers on Windows.
So an index array is used instead of NGX_USE_FD_EVENT to map
events to connections.

2 files changed, 75 insertions, 0 deletions

diff --git a/src/os/win32/ngx_socket.h b/src/os/win32/ngx_socket.h
index a9e26c295..f8a453d56 100644
--- a/src/os/win32/ngx_socket.h
+++ b/src/os/win32/ngx_socket.h
@@ -200,6 +200,49 @@ extern LPFN_CONNECTEX             ngx_connectex;
 extern LPFN_DISCONNECTEX          ngx_disconnectex;
 
 
+#if (NGX_HAVE_POLL && !defined POLLIN)
+
+/*
+ * WSAPoll() is only available if _WIN32_WINNT >= 0x0600.
+ * If it is not available during compilation, we try to
+ * load it dynamically at runtime.
+ */
+
+#define NGX_LOAD_WSAPOLL 1
+
+#define POLLRDNORM  0x0100
+#define POLLRDBAND  0x0200
+#define POLLIN      (POLLRDNORM | POLLRDBAND)
+#define POLLPRI     0x0400
+
+#define POLLWRNORM  0x0010
+#define POLLOUT     (POLLWRNORM)
+#define POLLWRBAND  0x0020
+
+#define POLLERR     0x0001
+#define POLLHUP     0x0002
+#define POLLNVAL    0x0004
+
+typedef struct pollfd {
+
+    SOCKET  fd;
+    SHORT   events;
+    SHORT   revents;
+
+} WSAPOLLFD, *PWSAPOLLFD, FAR *LPWSAPOLLFD;
+
+typedef int (WSAAPI *ngx_wsapoll_pt)(
+    LPWSAPOLLFD fdArray,
+    ULONG fds,
+    INT timeout
+    );
+
+extern ngx_wsapoll_pt             WSAPoll;
+extern ngx_uint_t                 ngx_have_wsapoll;
+
+#endif
+
+
 int ngx_tcp_push(ngx_socket_t s);
 #define ngx_tcp_push_n            "tcp_push()"
 
diff --git a/src/os/win32/ngx_win32_init.c b/src/os/win32/ngx_win32_init.c
index ec9b51efa..70bee8ef4 100644
--- a/src/os/win32/ngx_win32_init.c
+++ b/src/os/win32/ngx_win32_init.c
@@ -58,6 +58,12 @@ static GUID cx_guid = WSAID_CONNECTEX;
 static GUID dx_guid = WSAID_DISCONNECTEX;
 
 
+#if (NGX_LOAD_WSAPOLL)
+ngx_wsapoll_pt             WSAPoll;
+ngx_uint_t                 ngx_have_wsapoll;
+#endif
+
+
 ngx_int_t
 ngx_os_init(ngx_log_t *log)
 {
@@ -223,6 +229,32 @@ ngx_os_init(ngx_log_t *log)
                       ngx_close_socket_n " failed");
     }
 
+#if (NGX_LOAD_WSAPOLL)
+    {
+    HMODULE  hmod;
+
+    hmod = GetModuleHandle("ws2_32.dll");
+    if (hmod == NULL) {
+        ngx_log_error(NGX_LOG_NOTICE, log, ngx_errno,
+                      "GetModuleHandle(\"ws2_32.dll\") failed");
+        goto nopoll;
+    }
+
+    WSAPoll = (ngx_wsapoll_pt) GetProcAddress(hmod, "WSAPoll");
+    if (WSAPoll == NULL) {
+        ngx_log_error(NGX_LOG_NOTICE, log, ngx_errno,
+                      "GetProcAddress(\"WSAPoll\") failed");
+        goto nopoll;
+    }
+
+    ngx_have_wsapoll = 1;
+
+    }
+
+nopoll:
+
+#endif
+
     if (GetEnvironmentVariable("ngx_unique", ngx_unique, NGX_INT32_LEN + 1)
         != 0)
     {