* Remove stale lock files if it is held by the same hostname and the

pid is not running.

* Added rak::timer::from_seconds(uint32_t) and converted all uses to
this to avoid overflows etc.

* For each cycle through the tracker list without any successfull
connections, increase the timeout by 20 seconds.


git-svn-id: svn://rakshasa.no/libtorrent/trunk/rtorrent@635 e378c898-3ddf-0310-93e7-cc216c733640

src/utils/lockfile.cc

@@ -37,8 +37,11 @@
 #include "config.h"
 
 #include <cctype>
+#include <cerrno>
 #include <cstring>
+#include <sstream>
 #include <fcntl.h>
+#include <signal.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -47,6 +50,31 @@
 
 namespace utils {
 
+struct lockfile_valid_char {
+  bool operator () (char c) {
+    return !std::isgraph(c);
+  }
+};
+
+struct lockfile_valid_hostname {
+  bool operator () (char c) {
+    return !std::isgraph(c) || c == ':';
+  }
+};
+
+bool
+Lockfile::is_stale() {
+  process_type process = locked_by();
+
+  char buf[256];
+  
+  if (process.second <= 0 ||
+      ::gethostname(buf, 255) != 0 || buf != process.first)
+    return false;
+      
+  return ::kill(process.second, 0) != 0 && errno != EPERM;
+}
+
 bool
 Lockfile::try_lock() {
   if (m_path.empty()) {
@@ -54,6 +82,9 @@ Lockfile::try_lock() {
     return true;
   }
 
+  if (is_stale())
+    ::unlink(m_path.c_str());
+
   // Just do a simple locking for now that isn't safe for network
   // devices.
   int fd = ::open(m_path.c_str(), O_RDWR | O_CREAT | O_EXCL, 0444);
@@ -85,25 +116,46 @@ Lockfile::unlock() {
     return ::unlink(m_path.c_str()) != -1;
 }
 
-struct lockfile_valid_char {
-  bool operator () (char c) {
-    return !std::isgraph(c);
-  }
-};
-
-std::string
+Lockfile::process_type
 Lockfile::locked_by() const {
   int fd = ::open(m_path.c_str(), O_RDONLY);
   
   if (fd < 0)
-    return "<error>";
+    return process_type(std::string(), 0);
 
-  char buf[256];
-  int pos = read(fd, buf, 255);
+  char first[256];
+  char* last = first + std::max(read(fd, first, 255), 0);
 
+  *last = '\0';
   ::close(fd);
 
-  return std::string(buf, std::find_if(buf, buf + std::max(pos, 0), lockfile_valid_char()));
+  char* endHostname = std::find_if(first, last, lockfile_valid_hostname());
+  char* beginPid = endHostname;
+  char* endPid;
+
+  long long int pid;
+
+  if (beginPid + 2 >= last ||
+      *(beginPid++) != ':' ||
+      *(beginPid++) != '+' ||
+      (pid = strtoll(beginPid, &endPid, 10)) == 0 ||
+      endPid == NULL)
+    return process_type(std::string(), 0);
+    
+  return process_type(std::string(first, endHostname), pid);
+}
+
+std::string
+Lockfile::locked_by_as_string() const {
+  process_type p = locked_by();
+
+  if (p.first.empty())
+    return "<error>";
+
+  std::stringstream str;
+  str << p.first << ":+" << p.second;
+
+  return str.str();
 }
 
 }