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 #ifdef LISP_FEATURE_WIN32
  79 void* os_validate_recommit(os_vm_address_t addr, os_vm_size_t len);
  80 #endif
  81
  82 /* This function seems to undo the effect of os_validate(..). */
  83 extern void os_invalidate(os_vm_address_t addr, os_vm_size_t len);
  84
  85 /* This maps a file into memory, or calls lose(..) for various
  86  * failures. */
  87 extern os_vm_address_t os_map(int fd,
  88                               int offset,
  89                               os_vm_address_t addr,
  90                               os_vm_size_t len);
  91
  92 /* This presumably flushes the instruction cache, if that can be done
  93  * explicitly. (It doesn't seem to be an issue for the i386 port,
  94  * which is all that exists for SBCL. It might be important for some
  95  * other architecture which CMU CL has been ported to, though. */
  96 extern void os_flush_icache(os_vm_address_t addr, os_vm_size_t len);
  97
  98 /* This sets access rights for an area of memory, e.g.
  99  * write-protecting a page so that the garbage collector can find out
 100  * whether it's modified by handling the signal. */
 101 extern void os_protect(os_vm_address_t addr,
 102                        os_vm_size_t len,
 103                        os_vm_prot_t protection);
 104
 105 /* This returns true for an address which makes sense at the Lisp level. */
 106 extern boolean is_valid_lisp_addr(os_vm_address_t test);
 107
 108 /* Given a signal context, return the address for storage of the
 109  * register, of the specified offset, for that context. The offset is
 110  * defined in the storage class (SC) defined in the Lisp virtual
 111  * machine (i.e. the file "vm.lisp" for the appropriate architecture). */
 112 os_context_register_t *
 113 os_context_register_addr(os_context_t *context, int offset);
 114
 115 os_context_register_t *
 116 os_context_float_register_addr(os_context_t *context, int offset);
 117
 118 /* Given a signal context, return the address for storage of the
 119  * program counter for that context. */
 120 os_context_register_t *os_context_pc_addr(os_context_t *context);
 121 #ifdef ARCH_HAS_NPC_REGISTER
 122 os_context_register_t *os_context_npc_addr(os_context_t *context);
 123 #endif
 124 #ifdef ARCH_HAS_LINK_REGISTER
 125 os_context_register_t *os_context_lr_addr(os_context_t *context);
 126 #endif
 127
 128 /* Given a signal context, return the address for storage of the
 129  * system stack pointer for that context. */
 130 #ifdef ARCH_HAS_STACK_POINTER
 131 os_context_register_t *os_context_sp_addr(os_context_t *context);
 132 #endif
 133 /* Given a signal context, return the address for storage of the
 134  * signal mask for that context. */
 135 sigset_t *os_context_sigmask_addr(os_context_t *context);
 136
 137 /* (Note that there may be other accessors for os_context_t which
 138  * depend not only on the OS, but also on the architecture, e.g.
 139  * getting at EFL/EFLAGS on the x86. Such things are defined in the
 140  * architecture-dependence files, not the OS-dependence files.) */
 141
 142 /* These are not architecture-specific functions, but are instead
 143  * general utilities defined in terms of the architecture-specific
 144  * function os_validate(..) and os_invalidate(..).
 145  */
 146 extern os_vm_address_t os_allocate(os_vm_size_t len);
 147 extern void os_deallocate(os_vm_address_t addr, os_vm_size_t len);
 148
 149 /* FIXME: The os_trunc_foo(..) and os_round_foo(..) macros here could
 150  * be functions. */
 151
 152 #define os_trunc_to_page(addr) \
 153     (os_vm_address_t)(((uword_t)(addr))&~(os_vm_page_size-1))
 154 #define os_round_up_to_page(addr) \
 155     os_trunc_to_page((addr)+(os_vm_page_size-1))
 156
 157 #define os_trunc_size_to_page(size) \
 158     (os_vm_size_t)(((uword_t)(size))&~(os_vm_page_size-1))
 159 #define os_round_up_size_to_page(size) \
 160     os_trunc_size_to_page((size)+(os_vm_page_size-1))
 161
 162 /* KLUDGE: The errno error reporting system is an ugly nonreentrant
 163  * botch which nonetheless wasn't too painful in the old days.
 164  * However, it's obviously not good for multithreaded programs, and n
 165  * order to accommodate multithreading while retaining the C-level
 166  * syntax of the old UNIX interface, errno has now been changed from a
 167  * true variable to a preprocessor definition which is too hairy for
 168  * us to try to unscrew in Lisp code. Instead, Lisp code calls this
 169  * service routine to do whatever hackery is necessary in C code, and
 170  * to return the value in a way that Lisp can understand. */
 171 int os_get_errno(void);
 172
 173 /* Return an absolute path to the runtime executable, or NULL if this
 174  * information is unavailable.  Unless external_path is non-zero the
 175  * returned path may only be valid for the current process, ie:
 176  * something like /proc/curproc/file.  If a non-null pathname is
 177  * returned, it must be 'free'd. */
 178 extern char *os_get_runtime_executable_path(int external_path);
 179
 180 /* Write platforms specific ones when necessary. This is to get us off
 181  * the ground. */
 182 #if N_WORD_BITS == 32
 183 # define OS_VM_SIZE_FMT "u"
 184 # define OS_VM_SIZE_FMTX "x"
 185 #else
 186 #if defined(LISP_FEATURE_SB_WIN32)
 187 # define OS_VM_SIZE_FMT "Iu"
 188 # define OS_VM_SIZE_FMTX "Ix"
 189 #else
 190 # define OS_VM_SIZE_FMT "lu"
 191 # define OS_VM_SIZE_FMTX "lx"
 192 #endif
 193 #endif
 194
 195 /* FIXME: this is not the right place for this, but here we have
 196  * a convenient base type to hand. If it turns out we can just use
 197  * size_t everywhere, this can more to runtime.h. */
 198 typedef os_vm_size_t word_t;
 199 #define WORD_FMTX OS_VM_SIZE_FMTX
 200
 201 #ifdef LISP_FEATURE_SB_THREAD
 202 #  ifndef CANNOT_USE_POSIX_SEM_T
 203 #    include <semaphore.h>
 204      typedef sem_t os_sem_t;
 205 #  endif
 206    void os_sem_init(os_sem_t *sem, unsigned int value);
 207    void os_sem_wait(os_sem_t *sem, char *what);
 208    void os_sem_post(os_sem_t *sem, char *what);
 209    void os_sem_destroy(os_sem_t *sem);
 210 #endif
 211
 212 #endif