added poll() support so that the number of file handles is not limited (#502)

Makefile

@@ -456,6 +456,7 @@ test: qjs$(EXE)
 	$(WINE) ./qjs$(EXE) tests/test_worker.js
 ifndef CONFIG_WIN32
 	$(WINE) ./qjs$(EXE) tests/test_std.js
+	$(WINE) ./qjs$(EXE) tests/test_rw_handler.js
 endif
 ifdef CONFIG_SHARED_LIBS
 	$(WINE) ./qjs$(EXE) tests/test_bjson.js

quickjs-libc.c

@@ -46,6 +46,7 @@
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <sys/wait.h>
+#include <poll.h>
 
 #if defined(__FreeBSD__)
 extern char **environ;
@@ -87,6 +88,7 @@ typedef sig_t sighandler_t;
 typedef struct {
     struct list_head link;
     int fd;
+    int poll_fd_index; /* temporary use in js_os_poll() */
     JSValue rw_func[2];
 } JSOSRWHandler;
 
@@ -134,6 +136,7 @@ typedef struct {
     struct list_head link;
     JSWorkerMessagePipe *recv_pipe;
     JSValue on_message_func;
+    int poll_fd_index; /* temporary use in js_os_poll() */
 } JSWorkerMessageHandler;
 
 typedef struct {
@@ -152,6 +155,10 @@ typedef struct JSThreadState {
     int next_timer_id; /* for setTimeout() */
     /* not used in the main thread */
     JSWorkerMessagePipe *recv_pipe, *send_pipe;
+#if !defined(_WIN32)
+    struct pollfd *poll_fds;
+    int poll_fds_size;
+#endif    
 } JSThreadState;
 
 static uint64_t os_pending_signals;
@@ -2507,16 +2514,44 @@ static int js_os_poll(JSContext *ctx)
 
 #else
 
+static no_inline int js_poll_expand(JSThreadState *ts)
+{
+    struct pollfd *new_fds;
+    int new_size = max_int(ts->poll_fds_size +
+                           ts->poll_fds_size / 2, 16);
+    new_fds = realloc(ts->poll_fds, new_size * sizeof(struct pollfd));
+    if (!new_fds)
+        return -1;
+    ts->poll_fds = new_fds;
+    ts->poll_fds_size = new_size;
+    return 0;
+}
+
+static int js_poll_add_poll_fd(JSThreadState *ts, int *pnfds, int fd, int events)
+{
+    struct pollfd *fds;
+    int nfds;
+    nfds = *pnfds;
+    if (unlikely(nfds >= ts->poll_fds_size)) {
+        if (js_poll_expand(ts))
+            return -1;
+    }
+    fds = &ts->poll_fds[nfds++];
+    fds->fd = fd;
+    fds->events = events;
+    fds->revents = 0;
+    *pnfds = nfds;
+    return 0;
+}
+
 static int js_os_poll(JSContext *ctx)
 {
     JSRuntime *rt = JS_GetRuntime(ctx);
     JSThreadState *ts = JS_GetRuntimeOpaque(rt);
-    int ret, fd_max, min_delay;
+    int min_delay, nfds;
     int64_t cur_time, delay;
-    fd_set rfds, wfds;
     JSOSRWHandler *rh;
     struct list_head *el;
-    struct timeval tv, *tvp;
 
     /* only check signals in the main thread */
     if (!ts->recv_pipe &&
@@ -2558,46 +2593,49 @@ static int js_os_poll(JSContext *ctx)
                 min_delay = delay;
             }
         }
-        tv.tv_sec = min_delay / 1000;
-        tv.tv_usec = (min_delay % 1000) * 1000;
-        tvp = &tv;
     } else {
-        tvp = NULL;
+        min_delay = -1; /* infinite */
     }
 
-    FD_ZERO(&rfds);
-    FD_ZERO(&wfds);
-    fd_max = -1;
+    nfds = 0;
     list_for_each(el, &ts->os_rw_handlers) {
+        int events;
+
         rh = list_entry(el, JSOSRWHandler, link);
-        fd_max = max_int(fd_max, rh->fd);
+        events = 0;
         if (!JS_IsNull(rh->rw_func[0]))
-            FD_SET(rh->fd, &rfds);
+            events |= POLLIN;
         if (!JS_IsNull(rh->rw_func[1]))
-            FD_SET(rh->fd, &wfds);
+            events |= POLLOUT;
+        if (events) {
+            rh->poll_fd_index = nfds;
+            if (js_poll_add_poll_fd(ts, &nfds, rh->fd, events))
+                return -1;
+        }
     }
 
     list_for_each(el, &ts->port_list) {
         JSWorkerMessageHandler *port = list_entry(el, JSWorkerMessageHandler, link);
         if (!JS_IsNull(port->on_message_func)) {
             JSWorkerMessagePipe *ps = port->recv_pipe;
-            fd_max = max_int(fd_max, ps->waker.read_fd);
-            FD_SET(ps->waker.read_fd, &rfds);
+            port->poll_fd_index = nfds;
+            if (js_poll_add_poll_fd(ts, &nfds, ps->waker.read_fd, POLLIN))
+                return -1;
         }
     }
 
-    ret = select(fd_max + 1, &rfds, &wfds, NULL, tvp);
-    if (ret > 0) {
+    nfds = poll(ts->poll_fds, nfds, min_delay);
+    if (nfds > 0) {
         list_for_each(el, &ts->os_rw_handlers) {
             rh = list_entry(el, JSOSRWHandler, link);
             if (!JS_IsNull(rh->rw_func[0]) &&
-                FD_ISSET(rh->fd, &rfds)) {
+                (ts->poll_fds[rh->poll_fd_index].revents & (POLLERR | POLLHUP | POLLNVAL | POLLIN))) {
                 call_handler(ctx, rh->rw_func[0]);
                 /* must stop because the list may have been modified */
                 goto done;
             }
             if (!JS_IsNull(rh->rw_func[1]) &&
-                FD_ISSET(rh->fd, &wfds)) {
+                (ts->poll_fds[rh->poll_fd_index].revents & (POLLERR | POLLHUP | POLLNVAL | POLLOUT))) {
                 call_handler(ctx, rh->rw_func[1]);
                 /* must stop because the list may have been modified */
                 goto done;
@@ -2607,8 +2645,7 @@ static int js_os_poll(JSContext *ctx)
         list_for_each(el, &ts->port_list) {
             JSWorkerMessageHandler *port = list_entry(el, JSWorkerMessageHandler, link);
             if (!JS_IsNull(port->on_message_func)) {
-                JSWorkerMessagePipe *ps = port->recv_pipe;
-                if (FD_ISSET(ps->waker.read_fd, &rfds)) {
+                if (ts->poll_fds[port->poll_fd_index].revents != 0) {
                     if (handle_posted_message(rt, ctx, port))
                         goto done;
                 }
@@ -4164,6 +4201,8 @@ void js_std_free_handlers(JSRuntime *rt)
     }
 #endif
 
+    free(ts->poll_fds);
+    
     free(ts);
     JS_SetRuntimeOpaque(rt, NULL); /* fail safe */
 }

tests/test_rw_handler.js

@@ -0,0 +1,57 @@
+import * as std from "std";
+import * as os from "os";
+
+function assert(actual, expected, message) {
+    if (arguments.length == 1)
+        expected = true;
+
+    if (Object.is(actual, expected))
+        return;
+
+    if (actual !== null && expected !== null
+    &&  typeof actual == 'object' && typeof expected == 'object'
+    &&  actual.toString() === expected.toString())
+        return;
+
+    throw Error("assertion failed: got |" + actual + "|" +
+                ", expected |" + expected + "|" +
+                (message ? " (" + message + ")" : ""));
+}
+
+function handle_read(fd_r, fd_w, i)
+{
+    var buf = new Uint32Array(1);
+    var val, len;
+    len = os.read(fd_r, buf.buffer, 0, 4);
+    os.setReadHandler(fd_r, null);
+    val = buf[0];
+//    print("read fd=", fd_r, "val=", val, "len=", len);
+    assert(val, i);
+}
+
+function handle_write(fd_r, fd_w, i)
+{
+    var buf = new Uint32Array(1);
+    buf[0] = i;
+    os.write(fd_w, buf.buffer, 0, 4);
+    os.setWriteHandler(fd_w, null);
+}
+
+function test_rw_handlers(n)
+{
+    var tab, fd_r, fd_w, i;
+    tab = [];
+    for(i = 0; i < n; i++) {
+        tab[i] = os.pipe();
+        fd_r = tab[i][0];
+        fd_w = tab[i][1];
+        os.setReadHandler(fd_r, handle_read.bind(null, fd_r, fd_w, i));
+    }
+    for(i = n - 1; i >= 0; i--) {
+        fd_r = tab[i][0];
+        fd_w = tab[i][1];
+        os.setWriteHandler(fd_w, handle_write.bind(null, fd_r, fd_w, i));
+    }
+}
+
+test_rw_handlers(100);