Revert "Use res_ninit for thread safety and a timer for reloading resolv.conf on Linux."

This reverts commit d4f0dede964549af67f275ac6296c5e9add3fb03.
It caused a valgrind error.
TBR=craig.schlenter@gmail.com

Review URL: http://codereview.chromium.org/118220

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@17607 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 72 deletions

diff --git a/net/base/host_resolver.cc b/net/base/host_resolver.cc
index f7f8668..23a1c00 100644
--- a/net/base/host_resolver.cc
+++ b/net/base/host_resolver.cc
@@ -21,12 +21,6 @@
 #include "net/base/address_list.h"
 #include "net/base/net_errors.h"
 
-#if defined(OS_LINUX)
-#include "base/singleton.h"
-#include "base/thread_local_storage.h"
-#include "base/time.h"
-#endif
-
 #if defined(OS_WIN)
 #include "net/base/winsock_init.h"
 #endif
@@ -46,70 +40,6 @@ HostMapper* SetHostMapper(HostMapper* value) {
   return value;
 }
 
-#if defined(OS_LINUX)
-// On Linux changes to /etc/resolv.conf can go unnoticed thus resulting in
-// DNS queries failing either because nameservers are unknown on startup
-// or because nameserver info has changed as a result of e.g. connecting to
-// a new network. Some distributions patch glibc to stat /etc/resolv.conf
-// to try to automatically detect such changes but these patches are not
-// universal and even patched systems such as Jaunty appear to need calls
-// to res_ninit to reload the nameserver information in different threads.
-//
-// We adopt the Mozilla solution here which is to call res_ninit when
-// lookups fail and to rate limit the reloading to once per second per
-// thread.
-
-// Keep a timer per calling thread to rate limit the calling of res_ninit.
-class DnsReloadTimer {
- public:
-  DnsReloadTimer() {
-    tls_index_.Initialize(SlotReturnFunction);
-  }
-
-  ~DnsReloadTimer() { }
-
-  // Check if the timer for the calling thread has expired. When no
-  // timer exists for the calling thread, create one.
-  bool Expired() {
-    const base::TimeDelta kRetryTime = base::TimeDelta::FromSeconds(1);
-    base::TimeTicks now = base::TimeTicks::Now();
-    base::TimeTicks* timer_ptr =
-      static_cast<base::TimeTicks*>(tls_index_.Get());
-
-    if (!timer_ptr) {
-      timer_ptr = new base::TimeTicks();
-      *timer_ptr = base::TimeTicks::Now();
-      tls_index_.Set(timer_ptr);
-      // Return true to reload dns info on the first call for each thread.
-      return true;
-    } else if (now - *timer_ptr > kRetryTime) {
-      *timer_ptr = now;
-      return true;
-    } else {
-      return false;
-    }
-  }
-
-  // Free the allocated timer.
-  static void SlotReturnFunction(void* data) {
-    base::TimeTicks* tls_data = static_cast<base::TimeTicks*>(data);
-    delete tls_data;
-  }
-
- private:
-  // We use thread local storage to identify which base::TimeTicks to
-  // interact with.
-  static ThreadLocalStorage::Slot tls_index_ ;
-
-  DISALLOW_COPY_AND_ASSIGN(DnsReloadTimer);
-};
-
-// A TLS slot to the TimeTicks for the current thread.
-// static
-ThreadLocalStorage::Slot DnsReloadTimer::tls_index_(base::LINKER_INITIALIZED);
-
-#endif  // defined(OS_LINUX)
-
 static int HostResolverProc(
     const std::string& host, const std::string& port, struct addrinfo** out) {
   struct addrinfo hints = {0};
@@ -146,10 +76,9 @@ static int HostResolverProc(
 
   int err = getaddrinfo(host.c_str(), port.c_str(), &hints, out);
 #if defined(OS_LINUX)
-  net::DnsReloadTimer* dns_timer = Singleton<net::DnsReloadTimer>::get();
   // If we fail, re-initialise the resolver just in case there have been any
   // changes to /etc/resolv.conf and retry. See http://crbug.com/11380 for info.
-  if (err && dns_timer->Expired() && !res_ninit(&_res))
+  if (err && !res_init())
     err = getaddrinfo(host.c_str(), port.c_str(), &hints, out);
 #endif