src/runtime/os.h

   1 /*
   2  * common interface for OS-dependent functions
   3  */
   4
   5 /*
   6  * This software is part of the SBCL system. See the README file for
   7  * more information.
   8  *
   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.
  14  */
  15
  16 #if !defined(_OS_H_INCLUDED_)
  17
  18 #define _OS_H_INCLUDED_
  19
  20 #include "sbcl.h"
  21 #include "runtime.h"
  22
  23 /* Some standard preprocessor definitions and typedefs are needed from
  24  * the OS-specific #include files. This is an attempt to document
  25  * them on 20000729, by WHN the impatient reverse engineer.
  26  *
  27  * OS_VM_PROT_READ, OS_VM_PROT_WRITE, OS_VM_PROT_EXECUTE
  28  *   flags for mmap, mprotect, etc. controlling memory protection
  29  * os_vm_prot_t
  30  *   type used for flags for mmap, mprotect, etc.
  31  *
  32  * os_vm_address_t
  33  *   the type used to represent addresses? (dunno why not just void*)
  34  * os_vm_size_t, os_vm_off_t
  35  *   corresponding to standard (POSIX?) types size_t, off_t
  36  * os_context_t
  37  *   the type used to represent context in a POSIX sigaction SA_SIGACTION
  38  *   handler, i.e. the actual type of the thing pointed to by the
  39  *   void* third argument of a handler */
  40
  41 #include "target-os.h"
  42
  43
  44 #define OS_VM_PROT_ALL \
  45   (OS_VM_PROT_READ | OS_VM_PROT_WRITE | OS_VM_PROT_EXECUTE)
  46
  47 #define OS_VM_PROT_NONE 0
  48
  49 extern os_vm_size_t os_vm_page_size;
  50
  51 /* Do anything we need to do when starting up the runtime environment
  52  * in this OS. */
  53 extern void os_init(char *argv[], char *envp[]);
  54
  55 /* Install any OS-dependent low-level signal handlers which are needed
  56  * by the runtime environment. E.g. the signals raised by a violation
  57  * of the gencgc write barrier need to be caught at a low level, and
  58  * they may be SIGSEGV on one OS and SIGBUS on another, so we install
  59  * them in an OS-dependent way. */
  60 extern void os_install_interrupt_handlers(void);
  61
  62 /* Clear a possibly-huge region of memory using any tricks available to
  63  * do it efficiently, e.g. possibly unmapping it and then remapping it.
  64  *
  65  * FIXME: For the x86 Linux/OpenBSD/FreeBSD ports, I'd be somewhat
  66  * surprised if bzero() wasn't substantially as efficient as
  67  * any tricks like this. It might make sense to benchmark it
  68  * and simplify if the difference isn't too large. */
  69 extern void os_zero(os_vm_address_t addr, os_vm_size_t length);
  70
  71 /* It looks as though this function allocates 'len' bytes at 'addr',
  72  * or at an OS-chosen address if 'addr' is zero.
  73  *
  74  * FIXME: There was some documentation for these functions in
  75  * "hp-ux.c" in the old CMU CL code. Perhaps move/merge it in here. */
  76 extern os_vm_address_t os_validate(os_vm_address_t addr, os_vm_size_t len);
  77
  78 /* This function seems to undo the effect of os_validate(..). */
  79 extern void os_invalidate(os_vm_address_t addr, os_vm_size_t len);
  80
  81 /* This maps a file into memory, or calls lose(..) for various
  82  * failures. */
  83 extern os_vm_address_t os_map(int fd,
  84                               int offset,
  85                               os_vm_address_t addr,
  86                               os_vm_size_t len);
  87
  88 /* This presumably flushes the instruction cache, if that can be done
  89  * explicitly. (It doesn't seem to be an issue for the i386 port,
  90  * which is all that exists for SBCL. It might be important for some
  91  * other architecture which CMU CL has been ported to, though. */
  92 extern void os_flush_icache(os_vm_address_t addr, os_vm_size_t len);
  93
  94 /* This sets access rights for an area of memory, e.g.
  95  * write-protecting a page so that the garbage collector can find out
  96  * whether it's modified by handling the signal. */
  97 extern void os_protect(os_vm_address_t addr,
  98                        os_vm_size_t len,
  99                        os_vm_prot_t protection);
 100
 101 /* This returns true for an address which makes sense at the Lisp level. */
 102 extern boolean is_valid_lisp_addr(os_vm_address_t test);
 103
 104 /* Given a signal context, return the address for storage of the
 105  * register, of the specified offset, for that context. The offset is
 106  * defined in the storage class (SC) defined in the Lisp virtual
 107  * machine (i.e. the file "vm.lisp" for the appropriate architecture). */
 108 os_context_register_t *
 109 os_context_register_addr(os_context_t *context, int offset);
 110
 111 /* FIXME: Pending investigation, this #ifdef stays as alpha. If it
 112  * turns out that the alpha truly requires this, it can change to
 113  * ARCH_HAS_FLOAT_REGISTERS (currently #defined in alpha-arch.h -- CSR
 114  * 2002-02-04 */
 115 #ifdef LISP_FEATURE_ALPHA
 116 os_context_register_t *
 117 os_context_float_register_addr(os_context_t *context, int offset);
 118 #endif
 119
 120 /* Given a signal context, return the address for storage of the
 121  * program counter for that context. */
 122 os_context_register_t *os_context_pc_addr(os_context_t *context);
 123 #ifdef ARCH_HAS_NPC_REGISTER
 124 os_context_register_t *os_context_npc_addr(os_context_t *context);
 125 #endif
 126 #ifdef ARCH_HAS_LINK_REGISTER
 127 os_context_register_t *os_context_lr_addr(os_context_t *context);
 128 #endif
 129
 130 /* Given a signal context, return the address for storage of the
 131  * system stack pointer for that context. */
 132 #ifdef ARCH_HAS_STACK_POINTER
 133 os_context_register_t *os_context_sp_addr(os_context_t *context);
 134 #endif
 135 /* Given a signal context, return the address for storage of the
 136  * signal mask for that context. */
 137 sigset_t *os_context_sigmask_addr(os_context_t *context);
 138
 139 /* (Note that there may be other accessors for os_context_t which
 140  * depend not only on the OS, but also on the architecture, e.g.
 141  * getting at EFL/EFLAGS on the x86. Such things are defined in the
 142  * architecture-dependence files, not the OS-dependence files.) */
 143
 144 /* These are not architecture-specific functions, but are instead
 145  * general utilities defined in terms of the architecture-specific
 146  * function os_validate(..) and os_invalidate(..).
 147  */
 148 extern os_vm_address_t os_allocate(os_vm_size_t len);
 149 extern void os_deallocate(os_vm_address_t addr, os_vm_size_t len);
 150
 151 /* FIXME: The os_trunc_foo(..) and os_round_foo(..) macros here could
 152  * be functions. */
 153
 154 #define os_trunc_to_page(addr) \
 155     (os_vm_address_t)(((long)(addr))&~(os_vm_page_size-1))
 156 #define os_round_up_to_page(addr) \
 157     os_trunc_to_page((addr)+(os_vm_page_size-1))
 158
 159 #define os_trunc_size_to_page(size) \
 160     (os_vm_size_t)(((long)(size))&~(os_vm_page_size-1))
 161 #define os_round_up_size_to_page(size) \
 162     os_trunc_size_to_page((size)+(os_vm_page_size-1))
 163
 164 /* KLUDGE: The errno error reporting system is an ugly nonreentrant
 165  * botch which nonetheless wasn't too painful in the old days.
 166  * However, it's obviously not good for multithreaded programs, and n
 167  * order to accommodate multithreading while retaining the C-level
 168  * syntax of the old UNIX interface, errno has now been changed from a
 169  * true variable to a preprocessor definition which is too hairy for
 170  * us to try to unscrew in Lisp code. Instead, Lisp code calls this
 171  * service routine to do whatever hackery is necessary in C code, and
 172  * to return the value in a way that Lisp can understand. */
 173 int os_get_errno(void);
 174
 175 /* Return an absolute path to the runtime executable, or NULL if this
 176  * information is unavailable.  If a non-null pathname is returned, it
 177  * must be 'free'd. */
 178 extern char *os_get_runtime_executable_path(void);
 179
 180 #endif