1 /* OCaml bindings for libvirt.
2 * (C) Copyright 2007 Richard W.M. Jones, Red Hat Inc.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version,
9 * with the OCaml linking exception described in ../COPYING.LIB.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 /* Please read libvirt/README file. */
23 static char *Optstring_val (value strv);
24 typedef value (*Val_ptr_t) (void *);
25 static value Val_opt (void *ptr, Val_ptr_t Val_ptr);
26 /*static value option_default (value option, value deflt);*/
27 static void _raise_virterror (const char *fn) Noreturn;
28 static value Val_virterror (virErrorPtr err);
30 /* Use this around synchronous libvirt API calls to release the OCaml
31 * lock, allowing other threads to run simultaneously. 'code' must not
32 * perform any caml_* calls, run any OCaml code, or raise any exception.
33 * http://web.archive.org/web/20030521020915/http://caml.inria.fr/archives/200106/msg00199.html
35 #define NONBLOCKING(code) \
37 caml_enter_blocking_section (); \
39 caml_leave_blocking_section (); \
42 /* Check error condition from a libvirt function, and automatically raise
43 * an exception if one is found.
45 #define CHECK_ERROR(cond, fn) \
46 do { if (cond) _raise_virterror (fn); } while (0)
48 /*----------------------------------------------------------------------*/
50 /* Some notes about the use of custom blocks to store virConnectPtr,
51 * virDomainPtr and virNetworkPtr.
52 *------------------------------------------------------------------
54 * Libvirt does some tricky reference counting to keep track of
55 * virConnectPtr's, virDomainPtr's and virNetworkPtr's.
57 * There is only one function which can return a virConnectPtr
58 * (virConnectOpen*) and that allocates a new one each time.
60 * virDomainPtr/virNetworkPtr's on the other hand can be returned
61 * repeatedly (for the same underlying domain/network), and we must
62 * keep track of each one and explicitly free it with virDomainFree
63 * or virNetworkFree. If we lose track of one then the reference
64 * counting in libvirt will keep it open. We therefore wrap these
65 * in a custom block with a finalizer function.
67 * We also have to allow the user to explicitly free them, in
68 * which case we set the pointer inside the custom block to NULL.
69 * The finalizer notices this and doesn't free the object.
71 * Domains and networks "belong to" a connection. We have to avoid
72 * the situation like this:
74 * let conn = Connect.open ... in
75 * let dom = Domain.lookup_by_id conn 0 in
76 * (* conn goes out of scope and is garbage collected *)
77 * printf "dom name = %s\n" (Domain.get_name dom)
79 * The reason is that when conn is garbage collected, virConnectClose
80 * is called and any subsequent operations on dom will fail (in fact
81 * will probably segfault). To stop this from happening, the OCaml
82 * wrappers store domains (and networks) as explicit (dom, conn)
85 * Update 2008/01: Storage pools and volumes work the same way as
86 * domains and networks.
89 /* Unwrap a custom block. */
90 #define Connect_val(rv) (*((virConnectPtr *)Data_custom_val(rv)))
91 #define Dom_val(rv) (*((virDomainPtr *)Data_custom_val(rv)))
92 #define Net_val(rv) (*((virNetworkPtr *)Data_custom_val(rv)))
93 #define Pol_val(rv) (*((virStoragePoolPtr *)Data_custom_val(rv)))
94 #define Vol_val(rv) (*((virStorageVolPtr *)Data_custom_val(rv)))
96 /* Wrap up a pointer to something in a custom block. */
97 static value Val_connect (virConnectPtr conn);
98 static value Val_dom (virDomainPtr dom);
99 static value Val_net (virNetworkPtr net);
100 static value Val_pol (virStoragePoolPtr pool);
101 static value Val_vol (virStorageVolPtr vol);
103 /* Domains and networks are stored as pairs (dom/net, conn), so have
104 * some convenience functions for unwrapping and wrapping them.
106 #define Domain_val(rv) (Dom_val(Field((rv),0)))
107 #define Network_val(rv) (Net_val(Field((rv),0)))
108 #define Pool_val(rv) (Pol_val(Field((rv),0)))
109 #define Volume_val(rv) (Vol_val(Field((rv),0)))
110 #define Connect_domv(rv) (Connect_val(Field((rv),1)))
111 #define Connect_netv(rv) (Connect_val(Field((rv),1)))
112 #define Connect_polv(rv) (Connect_val(Field((rv),1)))
113 #define Connect_volv(rv) (Connect_val(Field((rv),1)))
115 static value Val_domain (virDomainPtr dom, value connv);
116 static value Val_network (virNetworkPtr net, value connv);
117 static value Val_pool (virStoragePoolPtr pol, value connv);
118 static value Val_volume (virStorageVolPtr vol, value connv);