added license GPL

[winnie] / src / shalloc.cc

diff --git a/src/shalloc.cc b/src/shalloc.cc
index b5c155f..3f47995 100644 (file)
--- a/src/shalloc.cc
+++ b/src/shalloc.cc
@@ -1,13 +1,42 @@
+/*
+winnie - an experimental window system
+
+Copyright (C) 2013 Eleni Maria Stea
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Author: Eleni Maria Stea <elene.mst@gmail.com>
+*/
+
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
 
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #include <map>
 
 #include "shalloc.h"
 
+#define SHMNAME        "/winnie.shm"
+
 #define POOL_SIZE 16777216
 #define BLOCK_SIZE 512
 
@@ -21,6 +50,7 @@ static void alloc_blocks(int block_pos, int num_blocks);
 static void free_blocks(int block_pos, int num_blocks);
 
 static void print_stats();
+static int fd;
 
 static unsigned char *pool;
 static std::map<int, int> alloc_sizes; //starting block -> number of blocks
@@ -39,9 +69,18 @@ static Statistics stats;
 
 bool init_shared_memory()
 {
-       if(!(pool = (unsigned char *)malloc(POOL_SIZE))) {
+       if(((fd = shm_open(SHMNAME, O_RDWR | O_CREAT, S_IRWXU)) == -1)) {
+               fprintf(stderr, "Failed to open shared memory: %s\n", strerror(errno));
                return false;
        }
+       ftruncate(fd, POOL_SIZE);
+
+       if((pool = (unsigned char*)mmap(0, POOL_SIZE, PROT_READ | PROT_WRITE,
+                                       MAP_SHARED, fd, 0)) == (void*)-1) {
+               fprintf(stderr, "Failed to map shared memory: %s\n", strerror(errno));
+       }
+
+       shm_unlink(SHMNAME);
 
        for(int i=0; i<BITMAP_SIZE; i++) {
                bitmap[i] = 0;
@@ -56,7 +95,9 @@ bool init_shared_memory()
 void destroy_shared_memory()
 {
        print_stats();
-       free(pool);
+       if(munmap(pool, POOL_SIZE) == -1) {
+               fprintf(stderr, "Failed to unmap shared memory: %s\n", strerror(errno));
+       }
 }
 
 void *sh_malloc(size_t bytes)