adb: increase the FD table size on Win32.

128 maximum FDs is a pretty low limit, which can easily be exhausted by
port forwarding. Bump the maximum up to 2048, and add a test that checks
whether we can actually use a few hundred sockets.

Bug: https://code.google.com/p/android/issues/detail?id=12141
Bug: http://b/28246942
Change-Id: Ia4a2ff776e8e58ec13378756f19d80392679ece9

adb/sysdeps_test.cpp

@@ -215,3 +215,32 @@ TEST_F(sysdeps_poll, disconnect) {
     // Linux returns POLLIN | POLLHUP, Windows returns just POLLHUP.
     EXPECT_EQ(POLLHUP, pfd.revents & POLLHUP);
 }
+
+TEST_F(sysdeps_poll, fd_count) {
+    // https://code.google.com/p/android/issues/detail?id=12141
+    static constexpr int num_sockets = 512;
+    std::vector<int> sockets;
+    std::vector<adb_pollfd> pfds;
+    sockets.resize(num_sockets * 2);
+    for (int32_t i = 0; i < num_sockets; ++i) {
+        ASSERT_EQ(0, adb_socketpair(&sockets[i * 2])) << strerror(errno);
+        ASSERT_TRUE(WriteFdExactly(sockets[i * 2], &i, sizeof(i)));
+        adb_pollfd pfd;
+        pfd.events = POLLIN;
+        pfd.fd = sockets[i * 2 + 1];
+        pfds.push_back(pfd);
+    }
+
+    ASSERT_EQ(num_sockets, adb_poll(pfds.data(), pfds.size(), 0));
+    for (int i = 0; i < num_sockets; ++i) {
+        ASSERT_NE(0, pfds[i].revents & POLLIN);
+
+        int32_t buf[2] = { -1, -1 };
+        ASSERT_EQ(adb_read(pfds[i].fd, buf, sizeof(buf)), static_cast<ssize_t>(sizeof(int32_t)));
+        ASSERT_EQ(i, buf[0]);
+    }
+
+    for (int fd : sockets) {
+        adb_close(fd);
+    }
+}

adb/sysdeps_win32.cpp

@@ -191,7 +191,7 @@ typedef struct FHRec_
 #define  fh_socket  u.socket
 
 #define  WIN32_FH_BASE    2048
-#define  WIN32_MAX_FHS    128
+#define  WIN32_MAX_FHS    2048
 
 static adb_mutex_t   _win32_lock;
 static  FHRec        _win32_fhs[ WIN32_MAX_FHS ];