fdlimit.patch

From 4023c008cdc9fe777c5fb3c4332bf2588cfca79c Mon Sep 17 00:00:00 2001
From: Vitaly Potyarkin <sio.wtf@gmail.com>
Date: Wed, 2 Jun 2021 14:59:15 +0300
Subject: [PATCH] Lift 1024 open files limit (switch to curl polling API)

Backported from https://github.com/transmission/transmission/pull/893
---
 CMakeLists.txt            |  2 +-
 configure.ac              |  2 +-
 libtransmission/fdlimit.c | 26 --------------
 libtransmission/web.c     | 73 ++++++++++-----------------------------
 4 files changed, 20 insertions(+), 83 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 62bf87b..eb009d5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -97,7 +97,7 @@ string(SUBSTRING "${TR_VCS_REVISION}" 0 10 TR_VCS_REVISION)

 set_property(GLOBAL PROPERTY USE_FOLDERS ON)

-set(CURL_MINIMUM            7.15.4)
+set(CURL_MINIMUM            7.28.0)
 set(EVENT2_MINIMUM          2.0.10)
 set(OPENSSL_MINIMUM         0.9.7)
 set(CYASSL_MINIMUM          3.0)
diff --git a/configure.ac b/configure.ac
index 57d3cae..1a1058a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -39,7 +39,7 @@ AM_CONDITIONAL(HAVE_REVISION_FILE, test -f REVISION)
 ##
 ##

-CURL_MINIMUM=7.15.4
+CURL_MINIMUM=7.28.0
 AC_SUBST(CURL_MINIMUM)
 LIBEVENT_MINIMUM=2.0.10
 AC_SUBST(LIBEVENT_MINIMUM)
diff --git a/libtransmission/fdlimit.c b/libtransmission/fdlimit.c
index 7886d17..bfdd492 100644
--- a/libtransmission/fdlimit.c
+++ b/libtransmission/fdlimit.c
@@ -10,11 +10,6 @@
 #include <inttypes.h>
 #include <string.h>

-#ifndef _WIN32
-#include <sys/time.h> /* getrlimit */
-#include <sys/resource.h> /* getrlimit */
-#endif
-
 #include "transmission.h"
 #include "error.h"
 #include "error-types.h"
@@ -389,27 +384,6 @@ static void ensureSessionFdInfoExists(tr_session* session)
         i = tr_new0(struct tr_fdInfo, 1);
         fileset_construct(&i->fileset, FILE_CACHE_SIZE);
         session->fdInfo = i;
-
-#ifndef _WIN32
-
-        /* set the open-file limit to the largest safe size wrt FD_SETSIZE */
-        struct rlimit limit;
-
-        if (getrlimit(RLIMIT_NOFILE, &limit) == 0)
-        {
-            int const old_limit = (int)limit.rlim_cur;
-            int const new_limit = MIN(limit.rlim_max, FD_SETSIZE);
-
-            if (new_limit != old_limit)
-            {
-                limit.rlim_cur = new_limit;
-                setrlimit(RLIMIT_NOFILE, &limit);
-                getrlimit(RLIMIT_NOFILE, &limit);
-                tr_logAddInfo("Changed open file limit from %d to %d", old_limit, (int)limit.rlim_cur);
-            }
-        }
-
-#endif
     }
 }

diff --git a/libtransmission/web.c b/libtransmission/web.c
index 744f576..4a12210 100644
--- a/libtransmission/web.c
+++ b/libtransmission/web.c
@@ -11,9 +11,6 @@
 #ifdef _WIN32
 #include <windows.h>
 #include <wincrypt.h>
-#include <ws2tcpip.h>
-#else
-#include <sys/select.h>
 #endif

 #include <curl/curl.h>
@@ -391,41 +388,6 @@ struct tr_web_task* tr_webRunWebseed(tr_torrent* tor, char const* url, char cons
     return tr_webRunImpl(tor->session, tr_torrentId(tor), url, range, NULL, done_func, done_func_user_data, buffer);
 }

-/**
- * Portability wrapper for select().
- *
- * http://msdn.microsoft.com/en-us/library/ms740141%28VS.85%29.aspx
- * On win32, any two of the parameters, readfds, writefds, or exceptfds,
- * can be given as null. At least one must be non-null, and any non-null
- * descriptor set must contain at least one handle to a socket.
- */
-static void tr_select(int nfds, fd_set* r_fd_set, fd_set* w_fd_set, fd_set* c_fd_set, struct timeval* t)
-{
-#ifdef _WIN32
-
-    (void)nfds;
-
-    if (r_fd_set->fd_count == 0 && w_fd_set->fd_count == 0 && c_fd_set->fd_count == 0)
-    {
-        long int const msec = t->tv_sec * 1000 + t->tv_usec / 1000;
-        tr_wait_msec(msec);
-    }
-    else if (select(0, r_fd_set->fd_count != 0 ? r_fd_set : NULL, w_fd_set->fd_count != 0 ? w_fd_set : NULL,
-        c_fd_set->fd_count != 0 ? c_fd_set : NULL, t) == -1)
-    {
-        char errstr[512];
-        int const e = EVUTIL_SOCKET_ERROR();
-        tr_net_strerror(errstr, sizeof(errstr), e);
-        dbgmsg("Error: select (%d) %s", e, errstr);
-    }
-
-#else
-
-    select(nfds, r_fd_set, w_fd_set, c_fd_set, t);
-
-#endif
-}
-
 static void tr_webThreadFunc(void* vsession)
 {
     char* str;
@@ -434,6 +396,7 @@ static void tr_webThreadFunc(void* vsession)
     int taskCount = 0;
     struct tr_web_task* task;
     tr_session* session = vsession;
+    uint32_t repeats = 0;

     /* try to enable ssl for https support; but if that fails,
      * try a plain vanilla init */
@@ -473,6 +436,7 @@ static void tr_webThreadFunc(void* vsession)
     for (;;)
     {
         long msec;
+        int numfds;
         int unused;
         CURLMsg* msg;
         CURLMcode mcode;
@@ -538,28 +502,27 @@ static void tr_webThreadFunc(void* vsession)

         if (msec > 0)
         {
-            int usec;
-            int max_fd;
-            struct timeval t;
-            fd_set r_fd_set;
-            fd_set w_fd_set;
-            fd_set c_fd_set;
-
-            max_fd = 0;
-            FD_ZERO(&r_fd_set);
-            FD_ZERO(&w_fd_set);
-            FD_ZERO(&c_fd_set);
-            curl_multi_fdset(multi, &r_fd_set, &w_fd_set, &c_fd_set, &max_fd);
-
             if (msec > THREADFUNC_MAX_SLEEP_MSEC)
             {
                 msec = THREADFUNC_MAX_SLEEP_MSEC;
             }

-            usec = msec * 1000;
-            t.tv_sec = usec / 1000000;
-            t.tv_usec = usec % 1000000;
-            tr_select(max_fd + 1, &r_fd_set, &w_fd_set, &c_fd_set, &t);
+            curl_multi_wait(multi, NULL, 0, msec, &numfds);
+            if (!numfds)
+            {
+                repeats++;
+                if (repeats > 1)
+                {
+                    /* curl_multi_wait() returns immediately if there are
+                     * no fds to wait for, so we need an explicit wait here
+                     * to emulate select() behavior */
+                    tr_wait_msec(MIN(msec, THREADFUNC_MAX_SLEEP_MSEC / 2));
+                }
+            }
+            else
+            {
+                repeats = 0;
+            }
         }

         /* call curl_multi_perform() */
--
2.30.2.windows.1