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 #ifdef LISP_FEATURE_RELOCATABLE_HEAP
  24 extern uword_t DYNAMIC_SPACE_START;
  25 #endif
  26
  27 #if defined(LISP_FEATURE_GENCGC) && !defined(ENABLE_PAGE_PROTECTION)
  28 /* Should we use page protection to help avoid the scavenging of pages
  29  * that don't have pointers to younger generations?
  30  * You can change this to 0 if you want SBCL not to install the handlers
  31  * for SIGSEGV and SIGBUS. That will slow down GC, but might be desirable
  32  * for debugging or for exploring GC strategies such as remembered sets */
  33 #define ENABLE_PAGE_PROTECTION 1
  34 #endif
  35
  36 #ifdef LISP_FEATURE_CHENEYGC
  37 #define INSTALL_SIG_MEMORY_FAULT_HANDLER 1
  38 #endif
  39 #ifdef LISP_FEATURE_GENCGC
  40 #define INSTALL_SIG_MEMORY_FAULT_HANDLER ENABLE_PAGE_PROTECTION
  41 #endif
  42
  43 /* Some standard preprocessor definitions and typedefs are needed from
  44  * the OS-specific #include files. This is an attempt to document
  45  * them on 20000729, by WHN the impatient reverse engineer.
  46  *
  47  * OS_VM_PROT_READ, OS_VM_PROT_WRITE, OS_VM_PROT_EXECUTE
  48  *   flags for mmap, mprotect, etc. controlling memory protection
  49  * os_vm_prot_t
  50  *   type used for flags for mmap, mprotect, etc.
  51  *
  52  * os_vm_address_t
  53  *   the type used to represent addresses? (dunno why not just void*)
  54  * os_vm_size_t, os_vm_off_t
  55  *   corresponding to standard (POSIX?) types size_t, off_t
  56  * os_context_t
  57  *   the type used to represent context in a POSIX sigaction SA_SIGACTION
  58  *   handler, i.e. the actual type of the thing pointed to by the
  59  *   void* third argument of a handler */
  60
  61 #include "target-os.h"
  62
  63
  64 #define OS_VM_PROT_ALL \
  65   (OS_VM_PROT_READ | OS_VM_PROT_WRITE | OS_VM_PROT_EXECUTE)
  66
  67 #define OS_VM_PROT_NONE 0
  68
  69 extern os_vm_size_t os_vm_page_size;
  70
  71 /* Do anything we need to do when starting up the runtime environment
  72  * in this OS. */
  73 extern void os_init(char *argv[], char *envp[]);
  74
  75 /* Install any OS-dependent low-level signal handlers which are needed
  76  * by the runtime environment. E.g. the signals raised by a violation
  77  * of the gencgc write barrier need to be caught at a low level, and
  78  * they may be SIGSEGV on one OS and SIGBUS on another, so we install
  79  * them in an OS-dependent way. */
  80 extern void os_install_interrupt_handlers(void);
  81
  82 /* Clear a possibly-huge region of memory using any tricks available to
  83  * do it efficiently, e.g. possibly unmapping it and then remapping it.
  84  *
  85  * FIXME: For the x86 Linux/OpenBSD/FreeBSD ports, I'd be somewhat
  86  * surprised if bzero() wasn't substantially as efficient as
  87  * any tricks like this. It might make sense to benchmark it
  88  * and simplify if the difference isn't too large. */
  89 extern void os_zero(os_vm_address_t addr, os_vm_size_t length);
  90
  91 /* It looks as though this function allocates 'len' bytes at 'addr',
  92  * or at an OS-chosen address if 'addr' is zero.
  93  *
  94  * FIXME: There was some documentation for these functions in
  95  * "hp-ux.c" in the old CMU CL code. Perhaps move/merge it in here. */
  96 #define MOVABLE 1
  97 #define NOT_MOVABLE 0
  98 extern os_vm_address_t os_validate(boolean movable,
  99                                    os_vm_address_t addr,
 100                                    os_vm_size_t len);
 101
 102 #ifdef LISP_FEATURE_WIN32
 103 void* os_validate_recommit(os_vm_address_t addr, os_vm_size_t len);
 104 #endif
 105
 106 /* This function seems to undo the effect of os_validate(..). */
 107 extern void os_invalidate(os_vm_address_t addr, os_vm_size_t len);
 108
 109 /* This maps a file into memory, or calls lose(..) for various
 110  * failures. */
 111 extern void os_map(int fd,
 112                    int offset,
 113                    os_vm_address_t addr,
 114                    os_vm_size_t len);
 115
 116 /* This presumably flushes the instruction cache, if that can be done
 117  * explicitly. (It doesn't seem to be an issue for the i386 port,
 118  * which is all that exists for SBCL. It might be important for some
 119  * other architecture which CMU CL has been ported to, though. */
 120 extern void os_flush_icache(os_vm_address_t addr, os_vm_size_t len);
 121
 122 /* This sets access rights for an area of memory, e.g.
 123  * write-protecting a page so that the garbage collector can find out
 124  * whether it's modified by handling the signal. */
 125 extern void os_protect(os_vm_address_t addr,
 126                        os_vm_size_t len,
 127                        os_vm_prot_t protection);
 128
 129 /* Return true for an address (with or without lowtag bits) within
 130  * any range of memory understood by the garbage collector. */
 131 extern boolean gc_managed_addr_p(lispobj test);
 132
 133 /* Given a signal context, return the address for storage of the
 134  * register, of the specified offset, for that context. The offset is
 135  * defined in the storage class (SC) defined in the Lisp virtual
 136  * machine (i.e. the file "vm.lisp" for the appropriate architecture). */
 137 os_context_register_t *
 138 os_context_register_addr(os_context_t *context, int offset);
 139
 140 os_context_register_t *
 141 os_context_float_register_addr(os_context_t *context, int offset);
 142
 143 /* Given a signal context, return the address for storage of the
 144  * program counter for that context. */
 145 os_context_register_t *os_context_pc_addr(os_context_t *context);
 146 #ifdef ARCH_HAS_NPC_REGISTER
 147 os_context_register_t *os_context_npc_addr(os_context_t *context);
 148 #endif
 149 #ifdef ARCH_HAS_LINK_REGISTER
 150 os_context_register_t *os_context_lr_addr(os_context_t *context);
 151 #endif
 152
 153 /* Given a signal context, return the address for storage of the
 154  * system stack pointer for that context. */
 155 #ifdef ARCH_HAS_STACK_POINTER
 156 os_context_register_t *os_context_sp_addr(os_context_t *context);
 157 #endif
 158 /* Given a signal context, return the address for storage of the
 159  * signal mask for that context. */
 160 sigset_t *os_context_sigmask_addr(os_context_t *context);
 161
 162 /* (Note that there may be other accessors for os_context_t which
 163  * depend not only on the OS, but also on the architecture, e.g.
 164  * getting at EFL/EFLAGS on the x86. Such things are defined in the
 165  * architecture-dependence files, not the OS-dependence files.) */
 166
 167 /* These are not architecture-specific functions, but are instead
 168  * general utilities defined in terms of the architecture-specific
 169  * function os_validate(..) and os_invalidate(..).
 170  */
 171 extern os_vm_address_t os_allocate(os_vm_size_t len);
 172 extern void os_deallocate(os_vm_address_t addr, os_vm_size_t len);
 173
 174 /* FIXME: The os_trunc_foo(..) and os_round_foo(..) macros here could
 175  * be functions. */
 176
 177 #define os_trunc_to_page(addr) \
 178     (os_vm_address_t)(((uword_t)(addr))&~(os_vm_page_size-1))
 179 #define os_round_up_to_page(addr) \
 180     os_trunc_to_page((addr)+(os_vm_page_size-1))
 181
 182 #define os_trunc_size_to_page(size) \
 183     (os_vm_size_t)(((uword_t)(size))&~(os_vm_page_size-1))
 184 #define os_round_up_size_to_page(size) \
 185     os_trunc_size_to_page((size)+(os_vm_page_size-1))
 186
 187 /* KLUDGE: The errno error reporting system is an ugly nonreentrant
 188  * botch which nonetheless wasn't too painful in the old days.
 189  * However, it's obviously not good for multithreaded programs, and n
 190  * order to accommodate multithreading while retaining the C-level
 191  * syntax of the old UNIX interface, errno has now been changed from a
 192  * true variable to a preprocessor definition which is too hairy for
 193  * us to try to unscrew in Lisp code. Instead, Lisp code calls this
 194  * service routine to do whatever hackery is necessary in C code, and
 195  * to return the value in a way that Lisp can understand. */
 196 int os_get_errno(void);
 197
 198 /* Return an absolute path to the runtime executable, or NULL if this
 199  * information is unavailable.  Unless external_path is non-zero the
 200  * returned path may only be valid for the current process, ie:
 201  * something like /proc/curproc/file.  If a non-null pathname is
 202  * returned, it must be 'free'd. */
 203 extern char *os_get_runtime_executable_path(int external_path);
 204
 205 /* Write platforms specific ones when necessary. This is to get us off
 206  * the ground. */
 207 #if N_WORD_BITS == 32
 208 # define OS_VM_SIZE_FMT "u"
 209 # define OS_VM_SIZE_FMTX "x"
 210 #else
 211 #if defined(LISP_FEATURE_SB_WIN32)
 212 # define OS_VM_SIZE_FMT "Iu"
 213 # define OS_VM_SIZE_FMTX "Ix"
 214 #else
 215 # define OS_VM_SIZE_FMT "lu"
 216 # define OS_VM_SIZE_FMTX "lx"
 217 #endif
 218 #endif
 219
 220 /* FIXME: this is not the right place for this, but here we have
 221  * a convenient base type to hand. If it turns out we can just use
 222  * size_t everywhere, this can more to runtime.h. */
 223 typedef os_vm_size_t word_t;
 224 #define WORD_FMTX OS_VM_SIZE_FMTX
 225
 226 #ifdef LISP_FEATURE_SB_THREAD
 227 #  ifndef CANNOT_USE_POSIX_SEM_T
 228 #    include <semaphore.h>
 229      typedef sem_t os_sem_t;
 230 #  endif
 231    void os_sem_init(os_sem_t *sem, unsigned int value);
 232    void os_sem_wait(os_sem_t *sem, char *what);
 233    void os_sem_post(os_sem_t *sem, char *what);
 234    void os_sem_destroy(os_sem_t *sem);
 235 #endif
 236
 237 #endif