r5:

[php5-apc.git] / apc_mmap.c

diff --git a/apc_mmap.c b/apc_mmap.c
new file mode 100644 (file)
index 0000000..8b9cccb
--- /dev/null
+++ b/apc_mmap.c
@@ -0,0 +1,139 @@
+/*
+  +----------------------------------------------------------------------+
+  | APC                                                                  |
+  +----------------------------------------------------------------------+
+  | Copyright (c) 2006 The PHP Group                                     |
+  +----------------------------------------------------------------------+
+  | This source file is subject to version 3.01 of the PHP license,      |
+  | that is bundled with this package in the file LICENSE, and is        |
+  | available through the world-wide-web at the following url:           |
+  | http://www.php.net/license/3_01.txt                                  |
+  | If you did not receive a copy of the PHP license and are unable to   |
+  | obtain it through the world-wide-web, please send a note to          |
+  | license@php.net so we can mail you a copy immediately.               |
+  +----------------------------------------------------------------------+
+  | Authors: Rasmus Lerdorf <rasmus@php.net>                             |
+  +----------------------------------------------------------------------+
+
+   This software was contributed to PHP by Community Connect Inc. in 2002
+   and revised in 2005 by Yahoo! Inc. to add support for PHP 5.1.
+   Future revisions and derivatives of this source code must acknowledge
+   Community Connect Inc. as the original contributor of this module by
+   leaving this note intact in the source code.
+
+   All other licensing and usage conditions are those of the PHP Group.
+
+ */
+
+/* $Id: apc_mmap.c,v 3.7 2007/12/20 23:00:51 shire Exp $ */
+
+#include "apc.h"
+
+#if APC_MMAP
+
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+/* 
+ * Some operating systems (like FreeBSD) have a MAP_NOSYNC flag that
+ * tells whatever update daemons might be running to not flush dirty
+ * vm pages to disk unless absolutely necessary.  My guess is that
+ * most systems that don't have this probably default to only synching
+ * to disk when absolutely necessary.
+ */
+#ifndef MAP_NOSYNC
+#define MAP_NOSYNC 0
+#endif
+
+void *apc_mmap(char *file_mask, size_t size)
+{
+    void* shmaddr;  /* the shared memory address */
+
+    /* If no filename was provided, do an anonymous mmap */
+    if(!file_mask || (file_mask && !strlen(file_mask))) {
+        shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+    } else {
+        int fd;
+
+        /* 
+         * If the filemask contains .shm we try to do a POSIX-compliant shared memory
+         * backed mmap which should avoid synchs on some platforms.  At least on
+         * FreeBSD this implies MAP_NOSYNC and on Linux it is equivalent of mmap'ing
+         * a file in a mounted shmfs.  For this to work on Linux you need to make sure
+         * you actually have shmfs mounted.  Also on Linux, make sure the file_mask you
+         * pass in has a leading / and no other /'s.  eg.  /apc.shm.XXXXXX
+         * On FreeBSD these are mapped onto the regular filesystem so you can put whatever
+         * path you want here.
+         */
+        if(strstr(file_mask,".shm")) {
+            mktemp(file_mask);
+            fd = shm_open(file_mask, O_CREAT|O_RDWR, S_IRUSR|S_IWUSR);
+            if(fd == -1) {
+                apc_eprint("apc_mmap: shm_open on %s failed:", file_mask);
+                return (void *)-1;
+            }
+            if (ftruncate(fd, size) < 0) {
+                close(fd);
+                shm_unlink(file_mask);
+                apc_eprint("apc_mmap: ftruncate failed:");
+                return (void *)-1;
+            }
+            shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+            shm_unlink(file_mask);
+            close(fd);
+        }
+        /*
+         * Support anonymous mmap through the /dev/zero interface as well
+         */
+        else if(!strcmp(file_mask,"/dev/zero")) {
+            fd = open("/dev/zero", O_RDWR, S_IRUSR | S_IWUSR);
+            if(fd == -1) {
+                apc_eprint("apc_mmap: open on /dev/zero failed:");
+                return (void *)-1;
+            }
+            shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+            close(fd);
+        }
+        /* 
+         * Otherwise we do a normal filesystem mmap
+         */
+        else {
+            fd = mkstemp(file_mask);
+            if(fd == -1) {
+                apc_eprint("apc_mmap: mkstemp on %s failed:", file_mask);
+                return (void *)-1;
+            }
+            if (ftruncate(fd, size) < 0) {
+                close(fd);
+                unlink(file_mask);
+                apc_eprint("apc_mmap: ftruncate failed:");
+            }
+            shmaddr = (void *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NOSYNC, fd, 0);
+            close(fd);
+            unlink(file_mask);
+        }
+    }
+    if((int)shmaddr == -1) {
+        apc_eprint("apc_mmap: mmap failed:");
+    }
+    return shmaddr;
+}
+
+void apc_unmap(void* shmaddr, size_t size)
+{
+    if (munmap(shmaddr, size) < 0) {
+        apc_wprint("apc_unmap: munmap failed:");
+    }
+}
+
+#endif
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ * vim600: expandtab sw=4 ts=4 sts=4 fdm=marker
+ * vim<600: expandtab sw=4 ts=4 sts=4
+ */