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 typedef value (*Val_const_ptr_t) (const void *);
27 static value Val_opt_const (const void *ptr, Val_const_ptr_t Val_ptr);
28 /*static value option_default (value option, value deflt);*/
29 static void _raise_virterror (const char *fn) Noreturn;
30 static value Val_virterror (virErrorPtr err);
31 static int _list_length (value listv);
32 static value Val_virconnectcredential (const virConnectCredentialPtr cred);
34 /* Use this around synchronous libvirt API calls to release the OCaml
35 * lock, allowing other threads to run simultaneously. 'code' must not
36 * perform any caml_* calls, run any OCaml code, or raise any exception.
37 * http://web.archive.org/web/20030521020915/http://caml.inria.fr/archives/200106/msg00199.html
39 #define NONBLOCKING(code) \
41 caml_enter_blocking_section (); \
43 caml_leave_blocking_section (); \
46 /* Check error condition from a libvirt function, and automatically raise
47 * an exception if one is found.
49 #define CHECK_ERROR(cond, fn) \
50 do { if (cond) _raise_virterror (fn); } while (0)
52 /*----------------------------------------------------------------------*/
54 /* Some notes about the use of custom blocks to store virConnectPtr,
55 * virDomainPtr and virNetworkPtr.
56 *------------------------------------------------------------------
58 * Libvirt does some tricky reference counting to keep track of
59 * virConnectPtr's, virDomainPtr's and virNetworkPtr's.
61 * There is only one function which can return a virConnectPtr
62 * (virConnectOpen*) and that allocates a new one each time.
64 * virDomainPtr/virNetworkPtr's on the other hand can be returned
65 * repeatedly (for the same underlying domain/network), and we must
66 * keep track of each one and explicitly free it with virDomainFree
67 * or virNetworkFree. If we lose track of one then the reference
68 * counting in libvirt will keep it open. We therefore wrap these
69 * in a custom block with a finalizer function.
71 * We also have to allow the user to explicitly free them, in
72 * which case we set the pointer inside the custom block to NULL.
73 * The finalizer notices this and doesn't free the object.
75 * Domains and networks "belong to" a connection. We have to avoid
76 * the situation like this:
78 * let conn = Connect.open ... in
79 * let dom = Domain.lookup_by_id conn 0 in
80 * (* conn goes out of scope and is garbage collected *)
81 * printf "dom name = %s\n" (Domain.get_name dom)
83 * The reason is that when conn is garbage collected, virConnectClose
84 * is called and any subsequent operations on dom will fail (in fact
85 * will probably segfault). To stop this from happening, the OCaml
86 * wrappers store domains (and networks) as explicit (dom, conn)
89 * Update 2008/01: Storage pools and volumes work the same way as
90 * domains and networks.
93 /* Unwrap a custom block. */
94 #define Connect_val(rv) (*((virConnectPtr *)Data_custom_val(rv)))
95 #define Dom_val(rv) (*((virDomainPtr *)Data_custom_val(rv)))
96 #define Net_val(rv) (*((virNetworkPtr *)Data_custom_val(rv)))
97 #define Pol_val(rv) (*((virStoragePoolPtr *)Data_custom_val(rv)))
98 #define Vol_val(rv) (*((virStorageVolPtr *)Data_custom_val(rv)))
100 /* Wrap up a pointer to something in a custom block. */
101 static value Val_connect (virConnectPtr conn);
102 static value Val_dom (virDomainPtr dom);
103 static value Val_net (virNetworkPtr net);
104 static value Val_pol (virStoragePoolPtr pool);
105 static value Val_vol (virStorageVolPtr vol);
107 /* Domains and networks are stored as pairs (dom/net, conn), so have
108 * some convenience functions for unwrapping and wrapping them.
110 #define Domain_val(rv) (Dom_val(Field((rv),0)))
111 #define Network_val(rv) (Net_val(Field((rv),0)))
112 #define Pool_val(rv) (Pol_val(Field((rv),0)))
113 #define Volume_val(rv) (Vol_val(Field((rv),0)))
114 #define Connect_domv(rv) (Connect_val(Field((rv),1)))
115 #define Connect_netv(rv) (Connect_val(Field((rv),1)))
116 #define Connect_polv(rv) (Connect_val(Field((rv),1)))
117 #define Connect_volv(rv) (Connect_val(Field((rv),1)))
119 static value Val_domain (virDomainPtr dom, value connv);
120 static value Val_network (virNetworkPtr net, value connv);
121 static value Val_pool (virStoragePoolPtr pol, value connv);
122 static value Val_volume (virStorageVolPtr vol, value connv);