libgo/runtime/runtime.h

   1 /* runtime.h -- runtime support for Go.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include "config.h"
   8
   9 #include "go-assert.h"
  10 #include <signal.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include <fcntl.h>
  17 #include <unistd.h>
  18 #include <pthread.h>
  19 #include <semaphore.h>
  20 #include <ucontext.h>
  21
  22 #ifdef HAVE_SYS_MMAN_H
  23 #include <sys/mman.h>
  24 #endif
  25
  26 #include "array.h"
  27 #include "go-alloc.h"
  28 #include "go-panic.h"
  29 #include "go-string.h"
  30
  31 /* This file supports C files copied from the 6g runtime library.
  32    This is a version of the 6g runtime.h rewritten for gccgo's version
  33    of the code.  */
  34
  35 typedef signed int   int8    __attribute__ ((mode (QI)));
  36 typedef unsigned int uint8   __attribute__ ((mode (QI)));
  37 typedef signed int   int16   __attribute__ ((mode (HI)));
  38 typedef unsigned int uint16  __attribute__ ((mode (HI)));
  39 typedef signed int   int32   __attribute__ ((mode (SI)));
  40 typedef unsigned int uint32  __attribute__ ((mode (SI)));
  41 typedef signed int   int64   __attribute__ ((mode (DI)));
  42 typedef unsigned int uint64  __attribute__ ((mode (DI)));
  43 typedef float        float32 __attribute__ ((mode (SF)));
  44 typedef double       float64 __attribute__ ((mode (DF)));
  45 typedef unsigned int uintptr __attribute__ ((mode (pointer)));
  46
  47 /* Defined types.  */
  48
  49 typedef uint8                   bool;
  50 typedef uint8                   byte;
  51 typedef struct  Func            Func;
  52 typedef struct  G               G;
  53 typedef union   Lock            Lock;
  54 typedef struct  M               M;
  55 typedef union   Note            Note;
  56 typedef struct  SigTab          SigTab;
  57 typedef struct  MCache          MCache;
  58 typedef struct  FixAlloc        FixAlloc;
  59 typedef struct  Hchan           Hchan;
  60 typedef struct  Timers          Timers;
  61 typedef struct  Timer           Timer;
  62
  63 typedef struct  __go_open_array         Slice;
  64 typedef struct  __go_string             String;
  65 typedef struct  __go_interface          Iface;
  66 typedef struct  __go_empty_interface    Eface;
  67 typedef struct  __go_type_descriptor    Type;
  68 typedef struct  __go_defer_stack        Defer;
  69 typedef struct  __go_panic_stack        Panic;
  70
  71 typedef struct  __go_func_type          FuncType;
  72 typedef struct  __go_map_type           MapType;
  73
  74 /*
  75  * per-cpu declaration.
  76  */
  77 extern M*       runtime_m(void);
  78 extern G*       runtime_g(void);
  79
  80 extern M        runtime_m0;
  81 extern G        runtime_g0;
  82
  83 /*
  84  * defined constants
  85  */
  86 enum
  87 {
  88         // G status
  89         //
  90         // If you add to this list, add to the list
  91         // of "okay during garbage collection" status
  92         // in mgc0.c too.
  93         Gidle,
  94         Grunnable,
  95         Grunning,
  96         Gsyscall,
  97         Gwaiting,
  98         Gmoribund,
  99         Gdead,
 100 };
 101 enum
 102 {
 103         true    = 1,
 104         false   = 0,
 105 };
 106
 107 /*
 108  * structures
 109  */
 110 union   Lock
 111 {
 112         uint32  key;    // futex-based impl
 113         M*      waitm;  // linked list of waiting M's (sema-based impl)
 114 };
 115 union   Note
 116 {
 117         uint32  key;    // futex-based impl
 118         M*      waitm;  // waiting M (sema-based impl)
 119 };
 120 struct  G
 121 {
 122         Defer*  defer;
 123         Panic*  panic;
 124         void*   exception;      // current exception being thrown
 125         bool    is_foreign;     // whether current exception from other language
 126         void    *gcstack;       // if status==Gsyscall, gcstack = stackbase to use during gc
 127         uintptr gcstack_size;
 128         void*   gcnext_segment;
 129         void*   gcnext_sp;
 130         void*   gcinitial_sp;
 131         ucontext_t gcregs;
 132         byte*   entry;          // initial function
 133         G*      alllink;        // on allg
 134         void*   param;          // passed parameter on wakeup
 135         bool    fromgogo;       // reached from gogo
 136         int16   status;
 137         int32   goid;
 138         uint32  selgen;         // valid sudog pointer
 139         const char*     waitreason;     // if status==Gwaiting
 140         G*      schedlink;
 141         bool    readyonstop;
 142         bool    ispanic;
 143         M*      m;              // for debuggers, but offset not hard-coded
 144         M*      lockedm;
 145         M*      idlem;
 146         int32   sig;
 147         int32   writenbuf;
 148         byte*   writebuf;
 149         uintptr sigcode0;
 150         uintptr sigcode1;
 151         // uintptr      sigpc;
 152         uintptr gopc;   // pc of go statement that created this goroutine
 153
 154         G*      dotraceback;
 155
 156         ucontext_t      context;
 157         void*           stack_context[10];
 158 };
 159
 160 struct  M
 161 {
 162         G*      g0;             // goroutine with scheduling stack
 163         G*      gsignal;        // signal-handling G
 164         G*      curg;           // current running goroutine
 165         int32   id;
 166         int32   mallocing;
 167         int32   gcing;
 168         int32   locks;
 169         int32   nomemprof;
 170         int32   waitnextg;
 171         int32   dying;
 172         int32   profilehz;
 173         int32   helpgc;
 174         uint32  fastrand;
 175         Note    havenextg;
 176         G*      nextg;
 177         M*      alllink;        // on allm
 178         M*      schedlink;
 179         MCache  *mcache;
 180         G*      lockedg;
 181         G*      idleg;
 182         uintptr createstack[32];        // Stack that created this thread.
 183         M*      nextwaitm;      // next M waiting for lock
 184         uintptr waitsema;       // semaphore for parking on locks
 185         uint32  waitsemacount;
 186         uint32  waitsemalock;
 187 };
 188
 189 struct  SigTab
 190 {
 191         int32   sig;
 192         int32   flags;
 193 };
 194 enum
 195 {
 196         SigNotify = 1<<0,       // let signal.Notify have signal, even if from kernel
 197         SigKill = 1<<1,         // if signal.Notify doesn't take it, exit quietly
 198         SigThrow = 1<<2,        // if signal.Notify doesn't take it, exit loudly
 199         SigPanic = 1<<3,        // if the signal is from the kernel, panic
 200         SigDefault = 1<<4,      // if the signal isn't explicitly requested, don't monitor it
 201 };
 202
 203 #ifndef NSIG
 204 #define NSIG 32
 205 #endif
 206
 207 // NOTE(rsc): keep in sync with extern.go:/type.Func.
 208 // Eventually, the loaded symbol table should be closer to this form.
 209 struct  Func
 210 {
 211         String  name;
 212         uintptr entry;  // entry pc
 213 };
 214
 215 /* Macros.  */
 216
 217 #ifdef GOOS_windows
 218 enum {
 219    Windows = 1
 220 };
 221 #else
 222 enum {
 223    Windows = 0
 224 };
 225 #endif
 226
 227 struct  Timers
 228 {
 229         Lock;
 230         G       *timerproc;
 231         bool            sleeping;
 232         bool            rescheduling;
 233         Note    waitnote;
 234         Timer   **t;
 235         int32   len;
 236         int32   cap;
 237 };
 238
 239 // Package time knows the layout of this structure.
 240 // If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
 241 struct  Timer
 242 {
 243         int32   i;              // heap index
 244
 245         // Timer wakes up at when, and then at when+period, ... (period > 0 only)
 246         // each time calling f(now, arg) in the timer goroutine, so f must be
 247         // a well-behaved function and not block.
 248         int64   when;
 249         int64   period;
 250         void    (*f)(int64, Eface);
 251         Eface   arg;
 252 };
 253
 254 /*
 255  * defined macros
 256  *    you need super-gopher-guru privilege
 257  *    to add this list.
 258  */
 259 #define nelem(x)        (sizeof(x)/sizeof((x)[0]))
 260 #define nil             ((void*)0)
 261 #define USED(v)         ((void) v)
 262
 263 /*
 264  * external data
 265  */
 266 G*      runtime_allg;
 267 G*      runtime_lastg;
 268 M*      runtime_allm;
 269 extern  int32   runtime_gomaxprocs;
 270 extern  bool    runtime_singleproc;
 271 extern  uint32  runtime_panicking;
 272 extern  int32   runtime_gcwaiting;              // gc is waiting to run
 273 int32   runtime_ncpu;
 274
 275 /*
 276  * common functions and data
 277  */
 278 int32   runtime_findnull(const byte*);
 279 void    runtime_dump(byte*, int32);
 280
 281 /*
 282  * very low level c-called
 283  */
 284 void    runtime_args(int32, byte**);
 285 void    runtime_osinit();
 286 void    runtime_goargs(void);
 287 void    runtime_goenvs(void);
 288 void    runtime_goenvs_unix(void);
 289 void    runtime_throw(const char*) __attribute__ ((noreturn));
 290 void    runtime_panicstring(const char*) __attribute__ ((noreturn));
 291 void    runtime_prints(const char*);
 292 void    runtime_printf(const char*, ...);
 293 void*   runtime_mal(uintptr);
 294 void    runtime_schedinit(void);
 295 void    runtime_initsig(void);
 296 void    runtime_sigenable(uint32 sig);
 297 int32   runtime_gotraceback(void);
 298 void    runtime_goroutineheader(G*);
 299 void    runtime_goroutinetrailer(G*);
 300 void    runtime_traceback();
 301 void    runtime_tracebackothers(G*);
 302 String  runtime_gostringnocopy(const byte*);
 303 void*   runtime_mstart(void*);
 304 G*      runtime_malg(int32, byte**, size_t*);
 305 void    runtime_minit(void);
 306 void    runtime_mallocinit(void);
 307 void    runtime_gosched(void);
 308 void    runtime_tsleep(int64);
 309 M*      runtime_newm(void);
 310 void    runtime_goexit(void);
 311 void    runtime_entersyscall(void) __asm__("syscall.Entersyscall");
 312 void    runtime_exitsyscall(void) __asm__("syscall.Exitsyscall");
 313 void    siginit(void);
 314 bool    __go_sigsend(int32 sig);
 315 int32   runtime_callers(int32, uintptr*, int32);
 316 int64   runtime_nanotime(void);
 317 int64   runtime_cputicks(void);
 318
 319 void    runtime_stoptheworld(void);
 320 void    runtime_starttheworld(bool);
 321 extern uint32 runtime_worldsema;
 322 G*      __go_go(void (*pfn)(void*), void*);
 323
 324 /*
 325  * mutual exclusion locks.  in the uncontended case,
 326  * as fast as spin locks (just a few user-level instructions),
 327  * but on the contention path they sleep in the kernel.
 328  * a zeroed Lock is unlocked (no need to initialize each lock).
 329  */
 330 void    runtime_lock(Lock*);
 331 void    runtime_unlock(Lock*);
 332
 333 /*
 334  * sleep and wakeup on one-time events.
 335  * before any calls to notesleep or notewakeup,
 336  * must call noteclear to initialize the Note.
 337  * then, exactly one thread can call notesleep
 338  * and exactly one thread can call notewakeup (once).
 339  * once notewakeup has been called, the notesleep
 340  * will return.  future notesleep will return immediately.
 341  * subsequent noteclear must be called only after
 342  * previous notesleep has returned, e.g. it's disallowed
 343  * to call noteclear straight after notewakeup.
 344  *
 345  * notetsleep is like notesleep but wakes up after
 346  * a given number of nanoseconds even if the event
 347  * has not yet happened.  if a goroutine uses notetsleep to
 348  * wake up early, it must wait to call noteclear until it
 349  * can be sure that no other goroutine is calling
 350  * notewakeup.
 351  */
 352 void    runtime_noteclear(Note*);
 353 void    runtime_notesleep(Note*);
 354 void    runtime_notewakeup(Note*);
 355 void    runtime_notetsleep(Note*, int64);
 356
 357 /*
 358  * low-level synchronization for implementing the above
 359  */
 360 uintptr runtime_semacreate(void);
 361 int32   runtime_semasleep(int64);
 362 void    runtime_semawakeup(M*);
 363 // or
 364 void    runtime_futexsleep(uint32*, uint32, int64);
 365 void    runtime_futexwakeup(uint32*, uint32);
 366
 367 /*
 368  * low level C-called
 369  */
 370 #define runtime_mmap mmap
 371 #define runtime_munmap munmap
 372 #define runtime_madvise madvise
 373 #define runtime_memclr(buf, size) __builtin_memset((buf), 0, (size))
 374 #define runtime_getcallerpc(p) __builtin_return_address(0)
 375
 376 #ifdef __rtems__
 377 void __wrap_rtems_task_variable_add(void **);
 378 #endif
 379
 380 /*
 381  * Names generated by gccgo.
 382  */
 383 #define runtime_printbool       __go_print_bool
 384 #define runtime_printfloat      __go_print_double
 385 #define runtime_printint        __go_print_int64
 386 #define runtime_printiface      __go_print_interface
 387 #define runtime_printeface      __go_print_empty_interface
 388 #define runtime_printstring     __go_print_string
 389 #define runtime_printpointer    __go_print_pointer
 390 #define runtime_printuint       __go_print_uint64
 391 #define runtime_printslice      __go_print_slice
 392 #define runtime_printcomplex    __go_print_complex
 393
 394 /*
 395  * runtime go-called
 396  */
 397 void    runtime_printbool(_Bool);
 398 void    runtime_printfloat(double);
 399 void    runtime_printint(int64);
 400 void    runtime_printiface(Iface);
 401 void    runtime_printeface(Eface);
 402 void    runtime_printstring(String);
 403 void    runtime_printpc(void*);
 404 void    runtime_printpointer(void*);
 405 void    runtime_printuint(uint64);
 406 void    runtime_printhex(uint64);
 407 void    runtime_printslice(Slice);
 408 void    runtime_printcomplex(__complex double);
 409
 410 struct __go_func_type;
 411 void reflect_call(const struct __go_func_type *, const void *, _Bool, _Bool,
 412                   void **, void **)
 413   asm ("reflect.call");
 414
 415 /* Functions.  */
 416 #define runtime_panic __go_panic
 417 #define runtime_write(d, v, n) write((d), (v), (n))
 418 #define runtime_malloc(s) __go_alloc(s)
 419 #define runtime_free(p) __go_free(p)
 420 #define runtime_strcmp(s1, s2) __builtin_strcmp((s1), (s2))
 421 #define runtime_mcmp(a, b, s) __builtin_memcmp((a), (b), (s))
 422 #define runtime_memmove(a, b, s) __builtin_memmove((a), (b), (s))
 423 #define runtime_exit(s) exit(s)
 424 MCache* runtime_allocmcache(void);
 425 void    free(void *v);
 426 #define runtime_cas(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
 427 #define runtime_casp(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
 428 #define runtime_xadd(p, v) __sync_add_and_fetch (p, v)
 429 #define runtime_xchg(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
 430 #define runtime_atomicload(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
 431 #define runtime_atomicstore(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
 432 #define runtime_atomicloadp(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
 433 #define runtime_atomicstorep(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
 434
 435 struct __go_func_type;
 436 bool    runtime_addfinalizer(void*, void(*fn)(void*), const struct __go_func_type *);
 437 #define runtime_getcallersp(p) __builtin_frame_address(1)
 438 int32   runtime_mcount(void);
 439 int32   runtime_gcount(void);
 440 void    runtime_dopanic(int32) __attribute__ ((noreturn));
 441 void    runtime_startpanic(void);
 442 void    runtime_ready(G*);
 443 const byte*     runtime_getenv(const char*);
 444 int32   runtime_atoi(const byte*);
 445 uint32  runtime_fastrand1(void);
 446
 447 void    runtime_sigprof(uint8 *pc, uint8 *sp, uint8 *lr, G *gp);
 448 void    runtime_resetcpuprofiler(int32);
 449 void    runtime_setcpuprofilerate(void(*)(uintptr*, int32), int32);
 450 void    runtime_usleep(uint32);
 451
 452 /*
 453  * runtime c-called (but written in Go)
 454  */
 455 void    runtime_printany(Eface)
 456      __asm__("runtime.Printany");
 457 void    runtime_newTypeAssertionError(const String*, const String*, const String*, const String*, Eface*)
 458      __asm__("runtime.NewTypeAssertionError");
 459 void    runtime_newErrorString(String, Eface*)
 460      __asm__("runtime.NewErrorString");
 461
 462 /*
 463  * wrapped for go users
 464  */
 465 bool    runtime_isInf(float64 f, int32 sign);
 466 #define runtime_isNaN(f) __builtin_isnan(f)
 467 void    runtime_semacquire(uint32 volatile *);
 468 void    runtime_semrelease(uint32 volatile *);
 469 int32   runtime_gomaxprocsfunc(int32 n);
 470 void    runtime_procyield(uint32);
 471 void    runtime_osyield(void);
 472 void    runtime_LockOSThread(void) __asm__("runtime.LockOSThread");
 473 void    runtime_UnlockOSThread(void) __asm__("runtime.UnlockOSThread");
 474
 475 bool    runtime_showframe(const unsigned char*);
 476
 477 uintptr runtime_memlimit(void);
 478
 479 // If appropriate, ask the operating system to control whether this
 480 // thread should receive profiling signals.  This is only necessary on OS X.
 481 // An operating system should not deliver a profiling signal to a
 482 // thread that is not actually executing (what good is that?), but that's
 483 // what OS X prefers to do.  When profiling is turned on, we mask
 484 // away the profiling signal when threads go to sleep, so that OS X
 485 // is forced to deliver the signal to a thread that's actually running.
 486 // This is a no-op on other systems.
 487 void    runtime_setprof(bool);
 488
 489 void    runtime_time_scan(void (*)(byte*, int64));
 490
 491 void    runtime_setsig(int32, bool, bool);
 492 #define runtime_setitimer setitimer
 493
 494 void    runtime_check(void);
 495
 496 // A list of global variables that the garbage collector must scan.
 497 struct root_list {
 498         struct root_list *next;
 499         struct root {
 500                 void *decl;
 501                 size_t size;
 502         } roots[];
 503 };
 504
 505 void    __go_register_gc_roots(struct root_list*);
 506
 507 // Size of stack space allocated using Go's allocator.
 508 // This will be 0 when using split stacks, as in that case
 509 // the stacks are allocated by the splitstack library.
 510 extern uintptr runtime_stacks_sys;
 511
 512 extern _Bool __go_file_line (uintptr, String*, String*, int *);