Package: libfcgi0ldbl
Version: 2.4.0-8.1
Severity: normal
Tags: patch

This bug was originally reported in Ubuntu:

https://bugs.launchpad.net/ubuntu/+source/libfcgi/+bug/933417

--- BEGIN UBUNTU BUG DESCRIPTION ---

libfcgi uses select syscall, when some applications tryes to use more than 1024 
connections from web-server it crashes. There is a solutions for this problem: 
use poll in os_unix.c instead of select. Patch with this change is attached to 
this bug. This patch was written in Yandex and successfully used for a several 
months.

LIBFCGI_OS_CLOSE_POLL_TIMEOUT and LIBFCGI_IS_AF_UNIX_KEEPER_POLL_TIMEOUT 
environment variables are added to control poll timeouts in Os_Close and 
is_af_unix_keeper functions accordingly.

$ lsb_release -rd
Description: Ubuntu 10.04.2 LTS
Release: 10.04

--- END UBUNTU BUG DESCRIPTION ---



I will attach the patch as well. I am not sure how to forward it to
upstream, as their developer information seems fairly sparse and hard
to find.




-- System Information:
Debian Release: wheezy/sid
  APT prefers precise-updates
  APT policy: (500, 'precise-updates'), (500, 'precise-security'), (500, 
'precise'), (100, 'precise-backports')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-26-generic (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libfcgi0ldbl depends on:
ii  libc6       2.15-0ubuntu10
ii  libgcc1     1:4.6.3-1ubuntu5
ii  libstdc++6  4.6.3-1ubuntu5

libfcgi0ldbl recommends no packages.

libfcgi0ldbl suggests no packages.

-- no debconf information
diff --git a/libfcgi/os_unix.c b/libfcgi/os_unix.c
index 73e6a7f..af35aee 100755
--- a/libfcgi/os_unix.c
+++ b/libfcgi/os_unix.c
@@ -42,6 +42,7 @@ static const char rcsid[] = "$Id: os_unix.c,v 1.37 2002/03/05 19:14:49 robs Exp
 #include <sys/time.h>
 #include <sys/un.h>
 #include <signal.h>
+#include <poll.h>
 
 #ifdef HAVE_NETDB_H
 #include <netdb.h>
@@ -103,6 +104,9 @@ static int volatile maxFd = -1;
 static int shutdownPending = FALSE;
 static int shutdownNow = FALSE;
 
+static int libfcgiOsClosePollTimeout = 2000;
+static int libfcgiIsAfUnixKeeperPollTimeout = 2000;
+
 void OS_ShutdownPending()
 {
     shutdownPending = TRUE;
@@ -168,6 +172,16 @@ int OS_LibInit(int stdioFds[3])
     if(libInitialized)
         return 0;
 
+    char *libfcgiOsClosePollTimeoutStr = getenv( "LIBFCGI_OS_CLOSE_POLL_TIMEOUT" );
+    if(libfcgiOsClosePollTimeoutStr) {
+        libfcgiOsClosePollTimeout = atoi(libfcgiOsClosePollTimeoutStr);
+    }
+
+    char *libfcgiIsAfUnixKeeperPollTimeoutStr = getenv( "LIBFCGI_IS_AF_UNIX_KEEPER_POLL_TIMEOUT" );
+    if(libfcgiIsAfUnixKeeperPollTimeoutStr) {
+        libfcgiIsAfUnixKeeperPollTimeout = atoi(libfcgiIsAfUnixKeeperPollTimeoutStr);
+    }
+
     asyncIoTable = (AioInfo *)malloc(asyncIoTableSize * sizeof(AioInfo));
     if(asyncIoTable == NULL) {
         errno = ENOMEM;
@@ -755,19 +769,16 @@ int OS_Close(int fd)
 
     if (shutdown(fd, 1) == 0)
     {
-        struct timeval tv;
-        fd_set rfds;
+        struct pollfd pfd;
         int rv;
         char trash[1024];
 
-        FD_ZERO(&rfds);
+        pfd.fd = fd;
+        pfd.events = POLLIN;
 
         do 
         {
-            FD_SET(fd, &rfds);
-            tv.tv_sec = 2;
-            tv.tv_usec = 0;
-            rv = select(fd + 1, &rfds, NULL, NULL, &tv);
+            rv = poll(&pfd, 1, libfcgiOsClosePollTimeout);
         }
         while (rv > 0 && read(fd, trash, sizeof(trash)) > 0);
     }
@@ -1116,13 +1127,11 @@ static int is_reasonable_accept_errno (const int error)
  */
 static int is_af_unix_keeper(const int fd)
 {
-    struct timeval tval = { READABLE_UNIX_FD_DROP_DEAD_TIMEVAL };
-    fd_set read_fds;
-
-    FD_ZERO(&read_fds);
-    FD_SET(fd, &read_fds);
+    struct pollfd pfd;
+    pfd.fd = fd;
+    pfd.events = POLLIN;
 
-    return select(fd + 1, &read_fds, NULL, NULL, &tval) >= 0 && FD_ISSET(fd, &read_fds);
+    return poll(&pfd, 1, libfcgiIsAfUnixKeeperPollTimeout) >= 0 && (pfd.revents & POLLIN);
 }
 
 /*

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