2 * common interface for OS-dependent functions
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
16 #if !defined(_OS_H_INCLUDED_)
18 #define _OS_H_INCLUDED_
22 /* Some standard preprocessor definitions and typedefs are needed from
23 * the OS-specific #include files. This is an attempt to document
24 * them on 20000729, by WHN the impatient reverse engineer.
26 * OS_VM_PROT_READ, OS_VM_PROT_WRITE, OS_VM_PROT_EXECUTE
27 * flags for mmap, mprotect, etc. controlling memory protection
29 * type used for flags for mmap, mprotect, etc.
32 * the type used to represent addresses? (dunno why not just void*)
33 * os_vm_size_t, os_vm_off_t
34 * corresponding to standard (POSIX?) types size_t, off_t
36 * the type used to represent context in a POSIX sigaction SA_SIGACTION
37 * handler, i.e. the actual type of the thing pointed to by the
38 * void* third argument of a handler */
39 #if defined __FreeBSD__
41 #elif defined __OpenBSD__
43 #elif defined __linux__
49 #define OS_VM_PROT_ALL \
50 (OS_VM_PROT_READ | OS_VM_PROT_WRITE | OS_VM_PROT_EXECUTE)
52 extern os_vm_size_t os_vm_page_size;
54 /* Do anything we need to do when starting up the runtime environment
56 extern void os_init(void);
58 /* Install any OS-dependent low-level signal handlers which are needed
59 * by the runtime environment. E.g. the signals raised by a violation
60 * of the gencgc write barrier need to be caught at a low level, and
61 * they may be SIGSEGV on one OS and SIGBUS on another, so we install
62 * them in an OS-dependent way. */
63 extern void os_install_interrupt_handlers(void);
65 /* Clear a possibly-huge region of memory using any tricks available to
66 * do it efficiently, e.g. possibly unmapping it and then remapping it.
68 * FIXME: For the x86 Linux/OpenBSD/FreeBSD ports, I'd be somewhat
69 * surprised if bzero() wasn't substantially as efficient as
70 * any tricks like this. It might make sense to benchmark it
71 * and simplify if the difference isn't too large. */
72 extern void os_zero(os_vm_address_t addr, os_vm_size_t length);
74 /* It looks as though this function allocates 'len' bytes at 'addr',
75 * or at an OS-chosen address if 'addr' is zero.
77 * FIXME: There was some documentation for these functions in
78 * "hp-ux.c" in the old CMU CL code. Perhaps move/merge it in here. */
79 extern os_vm_address_t os_validate(os_vm_address_t addr, os_vm_size_t len);
81 /* This function seems to undo the effect of os_validate(..). */
82 extern void os_invalidate(os_vm_address_t addr, os_vm_size_t len);
84 /* This maps a file into memory, or calls lose(..) for various
86 extern os_vm_address_t os_map(int fd,
91 /* This presumably flushes the instruction cache, if that can be done
92 * explicitly. (It doesn't seem to be an issue for the i386 port,
93 * which is all that exists for SBCL. It might be important for some
94 * other architecture which CMU CL has been ported to, though. */
95 extern void os_flush_icache(os_vm_address_t addr, os_vm_size_t len);
97 /* This sets access rights for an area of memory, e.g.
98 * write-protecting a page so that the garbage collector can find out
99 * whether it's modified by handling the signal. */
100 extern void os_protect(os_vm_address_t addr,
102 os_vm_prot_t protection);
104 /* This returns true for an address which makes sense at the Lisp level. */
105 extern boolean is_valid_lisp_addr(os_vm_address_t test);
107 /* Given a signal context, return the address for storage of the
108 * register, of the specified offset, for that context. The offset is
109 * defined in the storage class (SC) defined in the Lisp virtual
110 * machine (i.e. the file "vm.lisp" for the appropriate architecture). */
111 register_t *os_context_register_addr(os_context_t *context, int offset);
113 register_t *os_context_fpregister_addr(os_context_t *context, int offset);
116 /* Given a signal context, return the address for storage of the
117 * program counter for that context. */
118 register_t *os_context_pc_addr(os_context_t *context);
120 /* Given a signal context, return the address for storage of the
121 * system stack pointer for that context. */
122 register_t *os_context_sp_addr(os_context_t *context);
124 /* Given a signal context, return the address for storage of the
125 * signal mask for that context. */
126 sigset_t *os_context_sigmask_addr(os_context_t *context);
128 /* (Note that there may be other accessors for os_context_t which
129 * depend not only on the OS, but also on the architecture, e.g.
130 * getting at EFL/EFLAGS on the x86. Such things are defined in the
131 * architecture-dependence files, not the OS-dependence files.) */
133 /* These are not architecture-specific functions, but are instead
134 * general utilities defined in terms of the architecture-specific
135 * function os_validate(..) and os_invalidate(..).
137 * FIXME: os_reallocate(..) is complicated and seems no longer to be
138 * used for anything. Perhaps we could delete it? */
139 extern os_vm_address_t os_allocate(os_vm_size_t len);
140 extern os_vm_address_t os_allocate_at(os_vm_address_t addr, os_vm_size_t len);
141 extern os_vm_address_t os_reallocate(os_vm_address_t addr,
142 os_vm_size_t old_len,
144 extern void os_deallocate(os_vm_address_t addr, os_vm_size_t len);
147 /* FIXME: The os_trunc_foo(..) and os_round_foo(..) macros here could
150 #define os_trunc_to_page(addr) \
151 (os_vm_address_t)(((long)(addr))&~(os_vm_page_size-1))
152 #define os_round_up_to_page(addr) \
153 os_trunc_to_page((addr)+(os_vm_page_size-1))
155 #define os_trunc_size_to_page(size) \
156 (os_vm_size_t)(((long)(size))&~(os_vm_page_size-1))
157 #define os_round_up_size_to_page(size) \
158 os_trunc_size_to_page((size)+(os_vm_page_size-1))
160 /* KLUDGE: The errno error reporting system is an ugly nonreentrant
161 * botch which nonetheless wasn't too painful in the old days.
162 * However, it's obviously not good for multithreaded programs, and n
163 * order to accommodate multithreading while retaining the C-level
164 * syntax of the old UNIX interface, errno has now been changed from a
165 * true variable to a preprocessor definition which is too hairy for
166 * us to try to unscrew in Lisp code. Instead, Lisp code calls this
167 * service routine to do whatever hackery is necessary in C code, and
168 * to return the value in a way that Lisp can understand. */
169 int os_get_errno(void);