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 <setjmp.h>
  11 #include <signal.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <fcntl.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         jmp_buf 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         ucontext_t      context;
 155         void*           stack_context[10];
 156 };
 157
 158 struct  M
 159 {
 160         G*      g0;             // goroutine with scheduling stack
 161         G*      gsignal;        // signal-handling G
 162         G*      curg;           // current running goroutine
 163         int32   id;
 164         int32   mallocing;
 165         int32   gcing;
 166         int32   locks;
 167         int32   nomemprof;
 168         int32   waitnextg;
 169         int32   dying;
 170         int32   profilehz;
 171         int32   helpgc;
 172         uint32  fastrand;
 173         Note    havenextg;
 174         G*      nextg;
 175         M*      alllink;        // on allm
 176         M*      schedlink;
 177         MCache  *mcache;
 178         G*      lockedg;
 179         G*      idleg;
 180         uintptr createstack[32];        // Stack that created this thread.
 181         M*      nextwaitm;      // next M waiting for lock
 182         uintptr waitsema;       // semaphore for parking on locks
 183         uint32  waitsemacount;
 184         uint32  waitsemalock;
 185 };
 186
 187 struct  SigTab
 188 {
 189         int32   sig;
 190         int32   flags;
 191 };
 192 enum
 193 {
 194         SigNotify = 1<<0,       // let signal.Notify have signal, even if from kernel
 195         SigKill = 1<<1,         // if signal.Notify doesn't take it, exit quietly
 196         SigThrow = 1<<2,        // if signal.Notify doesn't take it, exit loudly
 197         SigPanic = 1<<3,        // if the signal is from the kernel, panic
 198         SigDefault = 1<<4,      // if the signal isn't explicitly requested, don't monitor it
 199 };
 200
 201 #ifndef NSIG
 202 #define NSIG 32
 203 #endif
 204
 205 // NOTE(rsc): keep in sync with extern.go:/type.Func.
 206 // Eventually, the loaded symbol table should be closer to this form.
 207 struct  Func
 208 {
 209         String  name;
 210         uintptr entry;  // entry pc
 211 };
 212
 213 /* Macros.  */
 214
 215 #ifdef GOOS_windows
 216 enum {
 217    Windows = 1
 218 };
 219 #else
 220 enum {
 221    Windows = 0
 222 };
 223 #endif
 224
 225 struct  Timers
 226 {
 227         Lock;
 228         G       *timerproc;
 229         bool            sleeping;
 230         bool            rescheduling;
 231         Note    waitnote;
 232         Timer   **t;
 233         int32   len;
 234         int32   cap;
 235 };
 236
 237 // Package time knows the layout of this structure.
 238 // If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
 239 struct  Timer
 240 {
 241         int32   i;              // heap index
 242
 243         // Timer wakes up at when, and then at when+period, ... (period > 0 only)
 244         // each time calling f(now, arg) in the timer goroutine, so f must be
 245         // a well-behaved function and not block.
 246         int64   when;
 247         int64   period;
 248         void    (*f)(int64, Eface);
 249         Eface   arg;
 250 };
 251
 252 /*
 253  * defined macros
 254  *    you need super-gopher-guru privilege
 255  *    to add this list.
 256  */
 257 #define nelem(x)        (sizeof(x)/sizeof((x)[0]))
 258 #define nil             ((void*)0)
 259 #define USED(v)         ((void) v)
 260
 261 /*
 262  * external data
 263  */
 264 G*      runtime_allg;
 265 G*      runtime_lastg;
 266 M*      runtime_allm;
 267 extern  int32   runtime_gomaxprocs;
 268 extern  bool    runtime_singleproc;
 269 extern  uint32  runtime_panicking;
 270 extern  int32   runtime_gcwaiting;              // gc is waiting to run
 271 int32   runtime_ncpu;
 272
 273 /*
 274  * common functions and data
 275  */
 276 int32   runtime_findnull(const byte*);
 277
 278 /*
 279  * very low level c-called
 280  */
 281 void    runtime_args(int32, byte**);
 282 void    runtime_osinit();
 283 void    runtime_goargs(void);
 284 void    runtime_goenvs(void);
 285 void    runtime_goenvs_unix(void);
 286 void    runtime_throw(const char*) __attribute__ ((noreturn));
 287 void    runtime_panicstring(const char*) __attribute__ ((noreturn));
 288 void*   runtime_mal(uintptr);
 289 void    runtime_schedinit(void);
 290 void    runtime_initsig(void);
 291 void    runtime_sigenable(uint32 sig);
 292 String  runtime_gostringnocopy(const byte*);
 293 void*   runtime_mstart(void*);
 294 G*      runtime_malg(int32, byte**, size_t*);
 295 void    runtime_minit(void);
 296 void    runtime_mallocinit(void);
 297 void    runtime_gosched(void);
 298 void    runtime_tsleep(int64);
 299 M*      runtime_newm(void);
 300 void    runtime_goexit(void);
 301 void    runtime_entersyscall(void) __asm__("libgo_syscall.syscall.Entersyscall");
 302 void    runtime_exitsyscall(void) __asm__("libgo_syscall.syscall.Exitsyscall");
 303 void    siginit(void);
 304 bool    __go_sigsend(int32 sig);
 305 int32   runtime_callers(int32, uintptr*, int32);
 306 int64   runtime_nanotime(void);
 307 int64   runtime_cputicks(void);
 308
 309 void    runtime_stoptheworld(void);
 310 void    runtime_starttheworld(bool);
 311 extern uint32 runtime_worldsema;
 312 G*      __go_go(void (*pfn)(void*), void*);
 313
 314 /*
 315  * mutual exclusion locks.  in the uncontended case,
 316  * as fast as spin locks (just a few user-level instructions),
 317  * but on the contention path they sleep in the kernel.
 318  * a zeroed Lock is unlocked (no need to initialize each lock).
 319  */
 320 void    runtime_lock(Lock*);
 321 void    runtime_unlock(Lock*);
 322
 323 /*
 324  * sleep and wakeup on one-time events.
 325  * before any calls to notesleep or notewakeup,
 326  * must call noteclear to initialize the Note.
 327  * then, exactly one thread can call notesleep
 328  * and exactly one thread can call notewakeup (once).
 329  * once notewakeup has been called, the notesleep
 330  * will return.  future notesleep will return immediately.
 331  * subsequent noteclear must be called only after
 332  * previous notesleep has returned, e.g. it's disallowed
 333  * to call noteclear straight after notewakeup.
 334  *
 335  * notetsleep is like notesleep but wakes up after
 336  * a given number of nanoseconds even if the event
 337  * has not yet happened.  if a goroutine uses notetsleep to
 338  * wake up early, it must wait to call noteclear until it
 339  * can be sure that no other goroutine is calling
 340  * notewakeup.
 341  */
 342 void    runtime_noteclear(Note*);
 343 void    runtime_notesleep(Note*);
 344 void    runtime_notewakeup(Note*);
 345 void    runtime_notetsleep(Note*, int64);
 346
 347 /*
 348  * low-level synchronization for implementing the above
 349  */
 350 uintptr runtime_semacreate(void);
 351 int32   runtime_semasleep(int64);
 352 void    runtime_semawakeup(M*);
 353 // or
 354 void    runtime_futexsleep(uint32*, uint32, int64);
 355 void    runtime_futexwakeup(uint32*, uint32);
 356
 357 /*
 358  * low level C-called
 359  */
 360 #define runtime_mmap mmap
 361 #define runtime_munmap munmap
 362 #define runtime_madvise madvise
 363 #define runtime_memclr(buf, size) __builtin_memset((buf), 0, (size))
 364 #define runtime_getcallerpc(p) __builtin_return_address(0)
 365
 366 #ifdef __rtems__
 367 void __wrap_rtems_task_variable_add(void **);
 368 #endif
 369
 370 /*
 371  * runtime go-called
 372  */
 373 void    runtime_panic(Eface);
 374 struct __go_func_type;
 375 void reflect_call(const struct __go_func_type *, const void *, _Bool, _Bool,
 376                   void **, void **)
 377   asm ("libgo_reflect.reflect.call");
 378
 379 /* Functions.  */
 380 #define runtime_panic __go_panic
 381 #define runtime_printf printf
 382 #define runtime_malloc(s) __go_alloc(s)
 383 #define runtime_free(p) __go_free(p)
 384 #define runtime_strcmp(s1, s2) __builtin_strcmp((s1), (s2))
 385 #define runtime_mcmp(a, b, s) __builtin_memcmp((a), (b), (s))
 386 #define runtime_memmove(a, b, s) __builtin_memmove((a), (b), (s))
 387 #define runtime_exit(s) exit(s)
 388 MCache* runtime_allocmcache(void);
 389 void    free(void *v);
 390 #define runtime_cas(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
 391 #define runtime_casp(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
 392 #define runtime_xadd(p, v) __sync_add_and_fetch (p, v)
 393 #define runtime_xchg(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
 394 #define runtime_atomicload(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
 395 #define runtime_atomicstore(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
 396 #define runtime_atomicloadp(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
 397 #define runtime_atomicstorep(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
 398
 399 struct __go_func_type;
 400 bool    runtime_addfinalizer(void*, void(*fn)(void*), const struct __go_func_type *);
 401 #define runtime_getcallersp(p) __builtin_frame_address(1)
 402 int32   runtime_mcount(void);
 403 int32   runtime_gcount(void);
 404 void    runtime_dopanic(int32) __attribute__ ((noreturn));
 405 void    runtime_startpanic(void);
 406 void    runtime_ready(G*);
 407 const byte*     runtime_getenv(const char*);
 408 int32   runtime_atoi(const byte*);
 409 uint32  runtime_fastrand1(void);
 410
 411 void    runtime_sigprof(uint8 *pc, uint8 *sp, uint8 *lr, G *gp);
 412 void    runtime_resetcpuprofiler(int32);
 413 void    runtime_setcpuprofilerate(void(*)(uintptr*, int32), int32);
 414 void    runtime_usleep(uint32);
 415
 416 /*
 417  * runtime c-called (but written in Go)
 418  */
 419 void    runtime_printany(Eface)
 420      __asm__("libgo_runtime.runtime.Printany");
 421 void    runtime_newTypeAssertionError(const String*, const String*, const String*, const String*, Eface*)
 422      __asm__("libgo_runtime.runtime.NewTypeAssertionError");
 423 void    runtime_newErrorString(String, Eface*)
 424      __asm__("libgo_runtime.runtime.NewErrorString");
 425
 426 /*
 427  * wrapped for go users
 428  */
 429 void    runtime_semacquire(uint32 volatile *);
 430 void    runtime_semrelease(uint32 volatile *);
 431 int32   runtime_gomaxprocsfunc(int32 n);
 432 void    runtime_procyield(uint32);
 433 void    runtime_osyield(void);
 434 void    runtime_LockOSThread(void) __asm__("libgo_runtime.runtime.LockOSThread");
 435 void    runtime_UnlockOSThread(void) __asm__("libgo_runtime.runtime.UnlockOSThread");
 436
 437 uintptr runtime_memlimit(void);
 438
 439 // If appropriate, ask the operating system to control whether this
 440 // thread should receive profiling signals.  This is only necessary on OS X.
 441 // An operating system should not deliver a profiling signal to a
 442 // thread that is not actually executing (what good is that?), but that's
 443 // what OS X prefers to do.  When profiling is turned on, we mask
 444 // away the profiling signal when threads go to sleep, so that OS X
 445 // is forced to deliver the signal to a thread that's actually running.
 446 // This is a no-op on other systems.
 447 void    runtime_setprof(bool);
 448
 449 void    runtime_time_scan(void (*)(byte*, int64));
 450
 451 void    runtime_setsig(int32, bool, bool);
 452 #define runtime_setitimer setitimer
 453
 454 void    runtime_check(void);
 455
 456 // A list of global variables that the garbage collector must scan.
 457 struct root_list {
 458         struct root_list *next;
 459         struct root {
 460                 void *decl;
 461                 size_t size;
 462         } roots[];
 463 };
 464
 465 void    __go_register_gc_roots(struct root_list*);