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 (virConnectPtr conn, const char *fn) Noreturn;
28 static void not_supported (const char *fn) Noreturn;
29 static value Val_virterror (virErrorPtr err);
31 /* Use this around synchronous libvirt API calls to release the OCaml
32 * lock, allowing other threads to run simultaneously. 'code' must not
33 * perform any caml_* calls, run any OCaml code, or raise any exception.
34 * http://web.archive.org/web/20030521020915/http://caml.inria.fr/archives/200106/msg00199.html
36 #define NONBLOCKING(code) \
38 caml_enter_blocking_section (); \
40 caml_leave_blocking_section (); \
43 /* Check error condition from a libvirt function, and automatically raise
44 * an exception if one is found.
46 #define CHECK_ERROR(cond, conn, fn) \
47 do { if (cond) _raise_virterror (conn, fn); } while (0)
49 /* For more about weak symbols, see:
50 * http://kolpackov.net/pipermail/notes/2004-March/000006.html
51 * We are using this to do runtime detection of library functions
52 * so that if we dynamically link with an older version of
53 * libvirt than we were compiled against, it won't fail (provided
54 * libvirt >= 0.2.1 - we don't support anything older).
58 #if (__GNUC__ == 3 && __GNUC_MINOR__ >= 3) || (__GNUC__ > 3)
59 #define HAVE_WEAK_SYMBOLS 1
64 #ifdef HAVE_WEAK_SYMBOLS
65 #define WEAK_SYMBOL_CHECK(sym) \
66 do { if (!sym) not_supported(#sym); } while (0)
68 #define WEAK_SYMBOL_CHECK(sym)
69 #endif /* HAVE_WEAK_SYMBOLS */
71 /*----------------------------------------------------------------------*/
73 /* Some notes about the use of custom blocks to store virConnectPtr,
74 * virDomainPtr and virNetworkPtr.
75 *------------------------------------------------------------------
77 * Libvirt does some tricky reference counting to keep track of
78 * virConnectPtr's, virDomainPtr's and virNetworkPtr's.
80 * There is only one function which can return a virConnectPtr
81 * (virConnectOpen*) and that allocates a new one each time.
83 * virDomainPtr/virNetworkPtr's on the other hand can be returned
84 * repeatedly (for the same underlying domain/network), and we must
85 * keep track of each one and explicitly free it with virDomainFree
86 * or virNetworkFree. If we lose track of one then the reference
87 * counting in libvirt will keep it open. We therefore wrap these
88 * in a custom block with a finalizer function.
90 * We also have to allow the user to explicitly free them, in
91 * which case we set the pointer inside the custom block to NULL.
92 * The finalizer notices this and doesn't free the object.
94 * Domains and networks "belong to" a connection. We have to avoid
95 * the situation like this:
97 * let conn = Connect.open ... in
98 * let dom = Domain.lookup_by_id conn 0 in
99 * (* conn goes out of scope and is garbage collected *)
100 * printf "dom name = %s\n" (Domain.get_name dom)
102 * The reason is that when conn is garbage collected, virConnectClose
103 * is called and any subsequent operations on dom will fail (in fact
104 * will probably segfault). To stop this from happening, the OCaml
105 * wrappers store domains (and networks) as explicit (dom, conn)
108 * Update 2008/01: Storage pools and volumes work the same way as
109 * domains and networks. And jobs.
112 /* Unwrap a custom block. */
113 #define Connect_val(rv) (*((virConnectPtr *)Data_custom_val(rv)))
114 #define Dom_val(rv) (*((virDomainPtr *)Data_custom_val(rv)))
115 #define Net_val(rv) (*((virNetworkPtr *)Data_custom_val(rv)))
116 #ifdef HAVE_VIRSTORAGEPOOLPTR
117 #define Pol_val(rv) (*((virStoragePoolPtr *)Data_custom_val(rv)))
119 #ifdef HAVE_VIRSTORAGEVOLPTR
120 #define Vol_val(rv) (*((virStorageVolPtr *)Data_custom_val(rv)))
122 #ifdef HAVE_VIRJOBPTR
123 #define Jb_val(rv) (*((virJobPtr *)Data_custom_val(rv)))
126 /* Wrap up a pointer to something in a custom block. */
127 static value Val_connect (virConnectPtr conn);
128 static value Val_dom (virDomainPtr dom);
129 static value Val_net (virNetworkPtr net);
130 #ifdef HAVE_VIRSTORAGEPOOLPTR
131 static value Val_pol (virStoragePoolPtr pool);
133 #ifdef HAVE_VIRSTORAGEVOLPTR
134 static value Val_vol (virStorageVolPtr vol);
136 #ifdef HAVE_VIRJOBPTR
137 static value Val_jb (virJobPtr jb);
140 /* Domains and networks are stored as pairs (dom/net, conn), so have
141 * some convenience functions for unwrapping and wrapping them.
143 #define Domain_val(rv) (Dom_val(Field((rv),0)))
144 #define Network_val(rv) (Net_val(Field((rv),0)))
145 #ifdef HAVE_VIRSTORAGEPOOLPTR
146 #define Pool_val(rv) (Pol_val(Field((rv),0)))
148 #ifdef HAVE_VIRSTORAGEVOLPTR
149 #define Volume_val(rv) (Vol_val(Field((rv),0)))
151 #ifdef HAVE_VIRJOBPTR
152 #define Job_val(rv) (Jb_val(Field((rv),0)))
154 #define Connect_domv(rv) (Connect_val(Field((rv),1)))
155 #define Connect_netv(rv) (Connect_val(Field((rv),1)))
156 #ifdef HAVE_VIRSTORAGEPOOLPTR
157 #define Connect_polv(rv) (Connect_val(Field((rv),1)))
159 #ifdef HAVE_VIRSTORAGEVOLPTR
160 #define Connect_volv(rv) (Connect_val(Field((rv),1)))
162 #ifdef HAVE_VIRJOBPTR
163 #define Connect_jobv(rv) (Connect_val(Field((rv),1)))
166 static value Val_domain (virDomainPtr dom, value connv);
167 static value Val_network (virNetworkPtr net, value connv);
168 #ifdef HAVE_VIRSTORAGEPOOLPTR
169 static value Val_pool (virStoragePoolPtr pol, value connv);
171 #ifdef HAVE_VIRSTORAGEVOLPTR
172 static value Val_volume (virStorageVolPtr vol, value connv);
174 #ifdef HAVE_VIRJOBPTR
175 static value Val_job (virJobPtr jb, value connv);