HEADS UP: you need to check out the latest libowfat! Huge allocations are now taken from mmap()ed regions, not from heap anymore

opentracker.c

@@ -83,7 +83,7 @@ int main( int argc, char **argv );
 static void httperror( const int64 s, const char *title, const char *message );
 static void httpresponse( const int64 s, char *data );
 
-static void sendmallocdata( const int64 s, char *buffer, const size_t size );
+static void sendmmapdata( const int64 s, char *buffer, const size_t size );
 static void senddata( const int64 s, char *buffer, const size_t size );
 
 static void server_mainloop( );
@@ -132,7 +132,7 @@ static void httperror( const int64 s, const char *title, const char *message ) {
   senddata(s,static_outbuf,reply_size);
 }
 
-static void sendmallocdata( const int64 s, char *buffer, size_t size ) {
+static void sendmmapdata( const int64 s, char *buffer, size_t size ) {
   struct http_data *h = io_getcookie( s );
   char *header;
   size_t header_size;
@@ -152,7 +152,7 @@ static void sendmallocdata( const int64 s, char *buffer, size_t size ) {
 
   iob_reset( &h->batch );
   iob_addbuf_free( &h->batch, header, header_size );
-  iob_addbuf_free( &h->batch, buffer, size );
+  iob_addbuf_munmap( &h->batch, buffer, size );
 
   /* writeable sockets timeout after twice the pool timeout
      which defaults to 5 minutes (e.g. after 10 minutes) */
@@ -253,7 +253,7 @@ LOG_TO_STDERR( "sync: %d.%d.%d.%d\n", h->ip[0], h->ip[1], h->ip[2], h->ip[3] );
 
     if( mode == SYNC_OUT ) {
       if( !( reply_size = return_changeset_for_tracker( &reply ) ) ) HTTPERROR_500;
-      return sendmallocdata( s, reply, reply_size );
+      return sendmmapdata( s, reply, reply_size );
     }
 
     /* Simple but proof for now */
@@ -305,7 +305,7 @@ LOG_TO_STDERR( "sync: %d.%d.%d.%d\n", h->ip[0], h->ip[1], h->ip[2], h->ip[3] );
 LOG_TO_STDERR( "stats: %d.%d.%d.%d - mode: dmem\n", h->ip[0], h->ip[1], h->ip[2], h->ip[3] );
 
           if( !( reply_size = return_memstat_for_tracker( &reply ) ) ) HTTPERROR_500;
-          return sendmallocdata( s, reply, reply_size );
+          return sendmmapdata( s, reply, reply_size );
           
         case STATS_UDP:
           t = time( NULL ) - ot_start_time;
@@ -380,9 +380,8 @@ SCRAPE_WORKAROUND:
 LOG_TO_STDERR( "scrp: %d.%d.%d.%d - FULL SCRAPE\n", h->ip[0], h->ip[1], h->ip[2], h->ip[3] );
 
       if( !( reply_size = return_fullscrape_for_tracker( &reply ) ) ) HTTPERROR_500;
-      if( (c = realloc( reply, reply_size ) ) ) reply = c;
       ot_overall_tcp_successfulannounces++;
-      return sendmallocdata( s, reply, reply_size );
+      return sendmmapdata( s, reply, reply_size );
     }
 
     /* Enough for http header + whole scrape string */

trackerlogic.c

@@ -27,8 +27,8 @@ static ot_vector accesslist;
 #define WANT_ACCESS_CONTROL
 #endif
 
-size_t changeset_size = 0;
-time_t last_clean_time = 0;
+static size_t changeset_size = 0;
+static time_t last_clean_time = 0;
 
 /* Converter function from memory to human readable hex strings
    - definitely not thread safe!!!
@@ -305,14 +305,16 @@ size_t return_peers_for_torrent( ot_torrent *torrent, size_t amount, char *reply
 /* Fetch full scrape info for all torrents */
 size_t return_fullscrape_for_tracker( char **reply ) {
   size_t torrent_count = 0, j;
+  size_t allocated, replysize, usedpages;
   int    i, k;
   char  *r;
 
   for( i=0; i<256; ++i )
     torrent_count += all_torrents[i].size;
 
-  // one extra for pro- and epilogue
-  if( !( r = *reply = malloc( 100*(1+torrent_count) ) ) ) return 0;
+  /* one extra for pro- and epilogue */
+  allocated = 100*(1+torrent_count);
+  if( !( r = *reply = mmap( NULL, allocated, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0 ) ) ) return 0;
 
   memmove( r, "d5:filesd", 9 ); r += 9;
   for( i=0; i<256; ++i ) {
@@ -334,11 +336,19 @@ size_t return_fullscrape_for_tracker( char **reply ) {
   }
 
   *r++='e'; *r++='e';
-  return r - *reply;
+
+  replysize = ( r - *reply );
+  if( allocated > replysize ) {
+    usedpages = 1 + ( replysize / getpagesize() );
+    munmap( *reply + usedpages * getpagesize(), allocated - replysize );
+  }
+
+  return replysize;
 }
 
 size_t return_memstat_for_tracker( char **reply ) {
   size_t torrent_count = 0, j;
+  size_t allocated, replysize, usedpages;
   int    i, k;
   char  *r;
 
@@ -347,7 +357,8 @@ size_t return_memstat_for_tracker( char **reply ) {
     torrent_count += torrents_list->size;
   }
 
-  if( !( r = *reply = malloc( 256*32 + (43+OT_POOLS_COUNT*32)*torrent_count ) ) ) return 0;
+  allocated = 256*32 + (43+OT_POOLS_COUNT*32)*torrent_count;
+  if( !( r = *reply = mmap( NULL, allocated, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0 ) ) ) return 0;
 
   for( i=0; i<256; ++i )
     r += sprintf( r, "%02X: %08X %08X\n", i, (unsigned int)all_torrents[i].size, (unsigned int)all_torrents[i].space );
@@ -363,7 +374,13 @@ size_t return_memstat_for_tracker( char **reply ) {
     }
   }
 
-  return r - *reply;
+  replysize = ( r - *reply );
+  if( allocated > replysize ) {
+    usedpages = 1 + ( replysize / getpagesize() );
+    munmap( *reply + usedpages * getpagesize(), allocated - replysize );
+  }
+
+  return replysize;
 }
 
 /* Fetches scrape info for a specific torrent */
@@ -506,9 +523,7 @@ size_t return_changeset_for_tracker( char **reply ) {
 
   clean_all_torrents();
 
-  *reply = malloc( 8 + changeset_size + 2 );
-  if( !*reply )
-    return 0;
+  if( !( *reply = mmap( NULL, 8 + changeset_size + 2, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0 ) ) ) return 0;
 
   memmove( *reply, "d4:syncd", 8 );
   for( i = 0; i < changeset.size; ++i ) {