github.com/prattmic/llgo-embedded@v0.0.0-20150820070356-41cfecea0e1e/third_party/gofrontend/libgo/runtime/runtime.h (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  #include "config.h"
     6  
     7  #include "go-assert.h"
     8  #include <complex.h>
     9  #include <signal.h>
    10  #include <stdio.h>
    11  #include <stdlib.h>
    12  #include <string.h>
    13  #include <sys/types.h>
    14  #include <sys/stat.h>
    15  #include <fcntl.h>
    16  #include <unistd.h>
    17  #include <pthread.h>
    18  #include <semaphore.h>
    19  #include <ucontext.h>
    20  
    21  #ifdef HAVE_SYS_MMAN_H
    22  #include <sys/mman.h>
    23  #endif
    24  
    25  #include "interface.h"
    26  #include "go-alloc.h"
    27  
    28  #define _STRINGIFY2_(x) #x
    29  #define _STRINGIFY_(x) _STRINGIFY2_(x)
    30  #define GOSYM_PREFIX _STRINGIFY_(__USER_LABEL_PREFIX__)
    31  
    32  /* This file supports C files copied from the 6g runtime library.
    33     This is a version of the 6g runtime.h rewritten for gccgo's version
    34     of the code.  */
    35  
    36  typedef signed int   int8    __attribute__ ((mode (QI)));
    37  typedef unsigned int uint8   __attribute__ ((mode (QI)));
    38  typedef signed int   int16   __attribute__ ((mode (HI)));
    39  typedef unsigned int uint16  __attribute__ ((mode (HI)));
    40  typedef signed int   int32   __attribute__ ((mode (SI)));
    41  typedef unsigned int uint32  __attribute__ ((mode (SI)));
    42  typedef signed int   int64   __attribute__ ((mode (DI)));
    43  typedef unsigned int uint64  __attribute__ ((mode (DI)));
    44  typedef float        float32 __attribute__ ((mode (SF)));
    45  typedef double       float64 __attribute__ ((mode (DF)));
    46  typedef signed int   intptr __attribute__ ((mode (pointer)));
    47  typedef unsigned int uintptr __attribute__ ((mode (pointer)));
    48  
    49  typedef intptr		intgo; // Go's int
    50  typedef uintptr		uintgo; // Go's uint
    51  
    52  typedef uintptr		uintreg;
    53  
    54  /* Defined types.  */
    55  
    56  typedef	uint8			bool;
    57  typedef	uint8			byte;
    58  typedef	struct	Func		Func;
    59  typedef	struct	G		G;
    60  typedef	struct	Lock		Lock;
    61  typedef	struct	M		M;
    62  typedef	struct	P		P;
    63  typedef	struct	Note		Note;
    64  typedef	struct	String		String;
    65  typedef	struct	FuncVal		FuncVal;
    66  typedef	struct	SigTab		SigTab;
    67  typedef	struct	MCache		MCache;
    68  typedef struct	FixAlloc	FixAlloc;
    69  typedef	struct	Hchan		Hchan;
    70  typedef	struct	Timers		Timers;
    71  typedef	struct	Timer		Timer;
    72  typedef	struct	GCStats		GCStats;
    73  typedef	struct	LFNode		LFNode;
    74  typedef	struct	ParFor		ParFor;
    75  typedef	struct	ParForThread	ParForThread;
    76  typedef	struct	CgoMal		CgoMal;
    77  typedef	struct	PollDesc	PollDesc;
    78  typedef	struct	DebugVars	DebugVars;
    79  
    80  typedef	struct	__go_open_array		Slice;
    81  typedef struct	__go_interface		Iface;
    82  typedef	struct	__go_empty_interface	Eface;
    83  typedef	struct	__go_type_descriptor	Type;
    84  typedef	struct	__go_defer_stack	Defer;
    85  typedef	struct	__go_panic_stack	Panic;
    86  
    87  typedef struct	__go_ptr_type		PtrType;
    88  typedef struct	__go_func_type		FuncType;
    89  typedef struct	__go_interface_type	InterfaceType;
    90  typedef struct	__go_map_type		MapType;
    91  typedef struct	__go_channel_type	ChanType;
    92  
    93  typedef struct  Traceback	Traceback;
    94  
    95  typedef struct	Location	Location;
    96  
    97  /*
    98   * Per-CPU declaration.
    99   */
   100  extern M*	runtime_m(void);
   101  extern G*	runtime_g(void);
   102  
   103  extern M	runtime_m0;
   104  extern G	runtime_g0;
   105  
   106  /*
   107   * defined constants
   108   */
   109  enum
   110  {
   111  	// G status
   112  	//
   113  	// If you add to this list, add to the list
   114  	// of "okay during garbage collection" status
   115  	// in mgc0.c too.
   116  	Gidle,
   117  	Grunnable,
   118  	Grunning,
   119  	Gsyscall,
   120  	Gwaiting,
   121  	Gmoribund_unused,  // currently unused, but hardcoded in gdb scripts
   122  	Gdead,
   123  };
   124  enum
   125  {
   126  	// P status
   127  	Pidle,
   128  	Prunning,
   129  	Psyscall,
   130  	Pgcstop,
   131  	Pdead,
   132  };
   133  enum
   134  {
   135  	true	= 1,
   136  	false	= 0,
   137  };
   138  enum
   139  {
   140  	PtrSize = sizeof(void*),
   141  };
   142  enum
   143  {
   144  	// Per-M stack segment cache size.
   145  	StackCacheSize = 32,
   146  	// Global <-> per-M stack segment cache transfer batch size.
   147  	StackCacheBatch = 16,
   148  };
   149  /*
   150   * structures
   151   */
   152  struct	Lock
   153  {
   154  	// Futex-based impl treats it as uint32 key,
   155  	// while sema-based impl as M* waitm.
   156  	// Used to be a union, but unions break precise GC.
   157  	uintptr	key;
   158  };
   159  struct	Note
   160  {
   161  	// Futex-based impl treats it as uint32 key,
   162  	// while sema-based impl as M* waitm.
   163  	// Used to be a union, but unions break precise GC.
   164  	uintptr	key;
   165  };
   166  struct String
   167  {
   168  	const byte*	str;
   169  	intgo		len;
   170  };
   171  struct FuncVal
   172  {
   173  	void	(*fn)(void);
   174  	// variable-size, fn-specific data here
   175  };
   176  struct	GCStats
   177  {
   178  	// the struct must consist of only uint64's,
   179  	// because it is casted to uint64[].
   180  	uint64	nhandoff;
   181  	uint64	nhandoffcnt;
   182  	uint64	nprocyield;
   183  	uint64	nosyield;
   184  	uint64	nsleep;
   185  };
   186  
   187  // A location in the program, used for backtraces.
   188  struct	Location
   189  {
   190  	uintptr	pc;
   191  	String	filename;
   192  	String	function;
   193  	intgo	lineno;
   194  };
   195  
   196  struct	G
   197  {
   198  	Defer*	defer;
   199  	Panic*	panic;
   200  	void*	exception;	// current exception being thrown
   201  	bool	is_foreign;	// whether current exception from other language
   202  	void	*gcstack;	// if status==Gsyscall, gcstack = stackbase to use during gc
   203  	uintptr	gcstack_size;
   204  	void*	gcnext_segment;
   205  	void*	gcnext_sp;
   206  	void*	gcinitial_sp;
   207  	ucontext_t gcregs;
   208  	byte*	entry;		// initial function
   209  	void*	param;		// passed parameter on wakeup
   210  	bool	fromgogo;	// reached from gogo
   211  	int16	status;
   212  	uint32	selgen;		// valid sudog pointer
   213  	int64	goid;
   214  	int64	waitsince;	// approx time when the G become blocked
   215  	const char*	waitreason;	// if status==Gwaiting
   216  	G*	schedlink;
   217  	bool	ispanic;
   218  	bool	issystem;	// do not output in stack dump
   219  	bool	isbackground;	// ignore in deadlock detector
   220  	bool	paniconfault;	// panic (instead of crash) on unexpected fault address
   221  	M*	m;		// for debuggers, but offset not hard-coded
   222  	M*	lockedm;
   223  	int32	sig;
   224  	int32	writenbuf;
   225  	byte*	writebuf;
   226  	uintptr	sigcode0;
   227  	uintptr	sigcode1;
   228  	// uintptr	sigpc;
   229  	uintptr	gopc;	// pc of go statement that created this goroutine
   230  
   231  	int32	ncgo;
   232  	CgoMal*	cgomal;
   233  
   234  	Traceback* traceback;
   235  
   236  	ucontext_t	context;
   237  	void*		stack_context[10];
   238  };
   239  
   240  struct	M
   241  {
   242  	G*	g0;		// goroutine with scheduling stack
   243  	G*	gsignal;	// signal-handling G
   244  	byte*	gsignalstack;
   245  	size_t	gsignalstacksize;
   246  	void	(*mstartfn)(void);
   247  	G*	curg;		// current running goroutine
   248  	G*	caughtsig;	// goroutine running during fatal signal
   249  	P*	p;		// attached P for executing Go code (nil if not executing Go code)
   250  	P*	nextp;
   251  	int32	id;
   252  	int32	mallocing;
   253  	int32	throwing;
   254  	int32	gcing;
   255  	int32	locks;
   256  	int32	softfloat;
   257  	int32	dying;
   258  	int32	profilehz;
   259  	int32	helpgc;
   260  	bool	spinning;	// M is out of work and is actively looking for work
   261  	bool	blocked;	// M is blocked on a Note
   262  	uint32	fastrand;
   263  	uint64	ncgocall;	// number of cgo calls in total
   264  	int32	ncgo;		// number of cgo calls currently in progress
   265  	CgoMal*	cgomal;
   266  	Note	park;
   267  	M*	alllink;	// on allm
   268  	M*	schedlink;
   269  	MCache	*mcache;
   270  	G*	lockedg;
   271  	Location createstack[32];	// Stack that created this thread.
   272  	uint32	locked;	// tracking for LockOSThread
   273  	M*	nextwaitm;	// next M waiting for lock
   274  	uintptr	waitsema;	// semaphore for parking on locks
   275  	uint32	waitsemacount;
   276  	uint32	waitsemalock;
   277  	GCStats	gcstats;
   278  	bool	needextram;
   279  	bool	dropextram;	// for gccgo: drop after call is done.
   280  	uint8	traceback;
   281  	bool	(*waitunlockf)(G*, void*);
   282  	void*	waitlock;
   283  	uintptr	end[];
   284  };
   285  
   286  struct P
   287  {
   288  	Lock	lock;
   289  
   290  	int32	id;
   291  	uint32	status;		// one of Pidle/Prunning/...
   292  	P*	link;
   293  	uint32	schedtick;	// incremented on every scheduler call
   294  	uint32	syscalltick;	// incremented on every system call
   295  	M*	m;		// back-link to associated M (nil if idle)
   296  	MCache*	mcache;
   297  	Defer*	deferpool;	// pool of available Defer structs (see panic.c)
   298  
   299  	// Cache of goroutine ids, amortizes accesses to runtime_sched.goidgen.
   300  	uint64	goidcache;
   301  	uint64	goidcacheend;
   302  
   303  	// Queue of runnable goroutines.
   304  	uint32	runqhead;
   305  	uint32	runqtail;
   306  	G*	runq[256];
   307  
   308  	// Available G's (status == Gdead)
   309  	G*	gfree;
   310  	int32	gfreecnt;
   311  
   312  	byte	pad[64];
   313  };
   314  
   315  // The m->locked word holds two pieces of state counting active calls to LockOSThread/lockOSThread.
   316  // The low bit (LockExternal) is a boolean reporting whether any LockOSThread call is active.
   317  // External locks are not recursive; a second lock is silently ignored.
   318  // The upper bits of m->lockedcount record the nesting depth of calls to lockOSThread
   319  // (counting up by LockInternal), popped by unlockOSThread (counting down by LockInternal).
   320  // Internal locks can be recursive. For instance, a lock for cgo can occur while the main
   321  // goroutine is holding the lock during the initialization phase.
   322  enum
   323  {
   324  	LockExternal = 1,
   325  	LockInternal = 2,
   326  };
   327  
   328  struct	SigTab
   329  {
   330  	int32	sig;
   331  	int32	flags;
   332  };
   333  enum
   334  {
   335  	SigNotify = 1<<0,	// let signal.Notify have signal, even if from kernel
   336  	SigKill = 1<<1,		// if signal.Notify doesn't take it, exit quietly
   337  	SigThrow = 1<<2,	// if signal.Notify doesn't take it, exit loudly
   338  	SigPanic = 1<<3,	// if the signal is from the kernel, panic
   339  	SigDefault = 1<<4,	// if the signal isn't explicitly requested, don't monitor it
   340  	SigHandling = 1<<5,	// our signal handler is registered
   341  	SigIgnored = 1<<6,	// the signal was ignored before we registered for it
   342  	SigGoExit = 1<<7,	// cause all runtime procs to exit (only used on Plan 9).
   343  };
   344  
   345  // Layout of in-memory per-function information prepared by linker
   346  // See http://golang.org/s/go12symtab.
   347  // Keep in sync with linker and with ../../libmach/sym.c
   348  // and with package debug/gosym.
   349  struct	Func
   350  {
   351  	String	name;
   352  	uintptr	entry;	// entry pc
   353  };
   354  
   355  #ifdef GOOS_nacl
   356  enum {
   357     NaCl = 1,
   358  };
   359  #else
   360  enum {
   361     NaCl = 0,
   362  };
   363  #endif
   364  
   365  #ifdef GOOS_windows
   366  enum {
   367     Windows = 1
   368  };
   369  #else
   370  enum {
   371     Windows = 0
   372  };
   373  #endif
   374  #ifdef GOOS_solaris
   375  enum {
   376     Solaris = 1
   377  };
   378  #else
   379  enum {
   380     Solaris = 0
   381  };
   382  #endif
   383  
   384  struct	Timers
   385  {
   386  	Lock	lock;
   387  	G	*timerproc;
   388  	bool		sleeping;
   389  	bool		rescheduling;
   390  	Note	waitnote;
   391  	Timer	**t;
   392  	int32	len;
   393  	int32	cap;
   394  };
   395  
   396  // Package time knows the layout of this structure.
   397  // If this struct changes, adjust ../time/sleep.go:/runtimeTimer.
   398  // For GOOS=nacl, package syscall knows the layout of this structure.
   399  // If this struct changes, adjust ../syscall/net_nacl.go:/runtimeTimer.
   400  struct	Timer
   401  {
   402  	intgo	i;	// heap index
   403  
   404  	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
   405  	// each time calling f(now, arg) in the timer goroutine, so f must be
   406  	// a well-behaved function and not block.
   407  	int64	when;
   408  	int64	period;
   409  	FuncVal	*fv;
   410  	Eface	arg;
   411  	uintptr	seq;
   412  };
   413  
   414  // Lock-free stack node.
   415  struct LFNode
   416  {
   417  	LFNode	*next;
   418  	uintptr	pushcnt;
   419  };
   420  
   421  // Parallel for descriptor.
   422  struct ParFor
   423  {
   424  	void (*body)(ParFor*, uint32);	// executed for each element
   425  	uint32 done;			// number of idle threads
   426  	uint32 nthr;			// total number of threads
   427  	uint32 nthrmax;			// maximum number of threads
   428  	uint32 thrseq;			// thread id sequencer
   429  	uint32 cnt;			// iteration space [0, cnt)
   430  	void *ctx;			// arbitrary user context
   431  	bool wait;			// if true, wait while all threads finish processing,
   432  					// otherwise parfor may return while other threads are still working
   433  	ParForThread *thr;		// array of thread descriptors
   434  	uint32 pad;			// to align ParForThread.pos for 64-bit atomic operations
   435  	// stats
   436  	uint64 nsteal;
   437  	uint64 nstealcnt;
   438  	uint64 nprocyield;
   439  	uint64 nosyield;
   440  	uint64 nsleep;
   441  };
   442  
   443  // Track memory allocated by code not written in Go during a cgo call,
   444  // so that the garbage collector can see them.
   445  struct CgoMal
   446  {
   447  	CgoMal	*next;
   448  	void	*alloc;
   449  };
   450  
   451  // Holds variables parsed from GODEBUG env var.
   452  struct DebugVars
   453  {
   454  	int32	allocfreetrace;
   455  	int32	efence;
   456  	int32	gctrace;
   457  	int32	gcdead;
   458  	int32	scheddetail;
   459  	int32	schedtrace;
   460  };
   461  
   462  extern bool runtime_precisestack;
   463  extern bool runtime_copystack;
   464  
   465  /*
   466   * defined macros
   467   *    you need super-gopher-guru privilege
   468   *    to add this list.
   469   */
   470  #define	nelem(x)	(sizeof(x)/sizeof((x)[0]))
   471  #define	nil		((void*)0)
   472  #define USED(v)		((void) v)
   473  #define	ROUND(x, n)	(((x)+(n)-1)&~(uintptr)((n)-1)) /* all-caps to mark as macro: it evaluates n twice */
   474  
   475  byte*	runtime_startup_random_data;
   476  uint32	runtime_startup_random_data_len;
   477  void	runtime_get_random_data(byte**, int32*);
   478  
   479  enum {
   480  	// hashinit wants this many random bytes
   481  	HashRandomBytes = 32
   482  };
   483  void	runtime_hashinit(void);
   484  
   485  void	runtime_traceback(void);
   486  void	runtime_tracebackothers(G*);
   487  enum
   488  {
   489  	// The maximum number of frames we print for a traceback
   490  	TracebackMaxFrames = 100,
   491  };
   492  
   493  /*
   494   * external data
   495   */
   496  extern	uintptr runtime_zerobase;
   497  extern	G**	runtime_allg;
   498  extern	uintptr runtime_allglen;
   499  extern	G*	runtime_lastg;
   500  extern	M*	runtime_allm;
   501  extern	P**	runtime_allp;
   502  extern	int32	runtime_gomaxprocs;
   503  extern	uint32	runtime_needextram;
   504  extern	uint32	runtime_panicking;
   505  extern	int8*	runtime_goos;
   506  extern	int32	runtime_ncpu;
   507  extern 	void	(*runtime_sysargs)(int32, uint8**);
   508  extern	uint32	runtime_Hchansize;
   509  extern	DebugVars	runtime_debug;
   510  extern	uintptr	runtime_maxstacksize;
   511  
   512  /*
   513   * common functions and data
   514   */
   515  #define runtime_strcmp(s1, s2) __builtin_strcmp((s1), (s2))
   516  #define runtime_strncmp(s1, s2, n) __builtin_strncmp((s1), (s2), (n))
   517  #define runtime_strstr(s1, s2) __builtin_strstr((s1), (s2))
   518  intgo	runtime_findnull(const byte*);
   519  intgo	runtime_findnullw(const uint16*);
   520  void	runtime_dump(byte*, int32);
   521  
   522  void	runtime_gogo(G*);
   523  struct __go_func_type;
   524  void	runtime_args(int32, byte**);
   525  void	runtime_osinit();
   526  void	runtime_goargs(void);
   527  void	runtime_goenvs(void);
   528  void	runtime_goenvs_unix(void);
   529  void	runtime_throw(const char*) __attribute__ ((noreturn));
   530  void	runtime_panicstring(const char*) __attribute__ ((noreturn));
   531  bool	runtime_canpanic(G*);
   532  void	runtime_prints(const char*);
   533  void	runtime_printf(const char*, ...);
   534  int32	runtime_snprintf(byte*, int32, const char*, ...);
   535  #define runtime_mcmp(a, b, s) __builtin_memcmp((a), (b), (s))
   536  #define runtime_memmove(a, b, s) __builtin_memmove((a), (b), (s))
   537  void*	runtime_mal(uintptr);
   538  String	runtime_gostring(const byte*);
   539  String	runtime_gostringnocopy(const byte*);
   540  void	runtime_schedinit(void);
   541  void	runtime_initsig(void);
   542  void	runtime_sigenable(uint32 sig);
   543  void	runtime_sigdisable(uint32 sig);
   544  int32	runtime_gotraceback(bool *crash);
   545  void	runtime_goroutineheader(G*);
   546  void	runtime_printtrace(Location*, int32, bool);
   547  #define runtime_open(p, f, m) open((p), (f), (m))
   548  #define runtime_read(d, v, n) read((d), (v), (n))
   549  #define runtime_write(d, v, n) write((d), (v), (n))
   550  #define runtime_close(d) close(d)
   551  void	runtime_ready(G*);
   552  const byte*	runtime_getenv(const char*);
   553  int32	runtime_atoi(const byte*);
   554  void*	runtime_mstart(void*);
   555  G*	runtime_malg(int32, byte**, size_t*);
   556  void	runtime_mpreinit(M*);
   557  void	runtime_minit(void);
   558  void	runtime_unminit(void);
   559  void	runtime_needm(void);
   560  void	runtime_dropm(void);
   561  void	runtime_signalstack(byte*, int32);
   562  MCache*	runtime_allocmcache(void);
   563  void	runtime_freemcache(MCache*);
   564  void	runtime_mallocinit(void);
   565  void	runtime_mprofinit(void);
   566  #define runtime_malloc(s) __go_alloc(s)
   567  #define runtime_free(p) __go_free(p)
   568  #define runtime_getcallersp(p) __builtin_frame_address(1)
   569  int32	runtime_mcount(void);
   570  int32	runtime_gcount(void);
   571  void	runtime_mcall(void(*)(G*));
   572  uint32	runtime_fastrand1(void);
   573  int32	runtime_timediv(int64, int32, int32*);
   574  int32	runtime_round2(int32 x); // round x up to a power of 2.
   575  
   576  // atomic operations
   577  #define runtime_cas(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
   578  #define runtime_cas64(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
   579  #define runtime_casp(pval, old, new) __sync_bool_compare_and_swap (pval, old, new)
   580  // Don't confuse with XADD x86 instruction,
   581  // this one is actually 'addx', that is, add-and-fetch.
   582  #define runtime_xadd(p, v) __sync_add_and_fetch (p, v)
   583  #define runtime_xadd64(p, v) __sync_add_and_fetch (p, v)
   584  #define runtime_xchg(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
   585  #define runtime_xchg64(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
   586  #define runtime_xchgp(p, v) __atomic_exchange_n (p, v, __ATOMIC_SEQ_CST)
   587  #define runtime_atomicload(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
   588  #define runtime_atomicstore(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
   589  #define runtime_atomicstore64(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
   590  #define runtime_atomicload64(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
   591  #define runtime_atomicloadp(p) __atomic_load_n (p, __ATOMIC_SEQ_CST)
   592  #define runtime_atomicstorep(p, v) __atomic_store_n (p, v, __ATOMIC_SEQ_CST)
   593  
   594  void runtime_setmg(M*, G*);
   595  void runtime_newextram(void);
   596  #define runtime_exit(s) exit(s)
   597  #define runtime_breakpoint() __builtin_trap()
   598  void	runtime_gosched(void);
   599  void	runtime_gosched0(G*);
   600  void	runtime_schedtrace(bool);
   601  void	runtime_park(bool(*)(G*, void*), void*, const char*);
   602  void	runtime_parkunlock(Lock*, const char*);
   603  void	runtime_tsleep(int64, const char*);
   604  M*	runtime_newm(void);
   605  void	runtime_goexit(void);
   606  void	runtime_entersyscall(void) __asm__ (GOSYM_PREFIX "syscall.Entersyscall");
   607  void	runtime_entersyscallblock(void);
   608  void	runtime_exitsyscall(void) __asm__ (GOSYM_PREFIX "syscall.Exitsyscall");
   609  G*	__go_go(void (*pfn)(void*), void*);
   610  void	siginit(void);
   611  bool	__go_sigsend(int32 sig);
   612  int32	runtime_callers(int32, Location*, int32, bool keep_callers);
   613  int64	runtime_nanotime(void);	// monotonic time
   614  int64	runtime_unixnanotime(void); // real time, can skip
   615  void	runtime_dopanic(int32) __attribute__ ((noreturn));
   616  void	runtime_startpanic(void);
   617  void	runtime_freezetheworld(void);
   618  void	runtime_unwindstack(G*, byte*);
   619  void	runtime_sigprof();
   620  void	runtime_resetcpuprofiler(int32);
   621  void	runtime_setcpuprofilerate(void(*)(uintptr*, int32), int32);
   622  void	runtime_usleep(uint32);
   623  int64	runtime_cputicks(void);
   624  int64	runtime_tickspersecond(void);
   625  void	runtime_blockevent(int64, int32);
   626  extern int64 runtime_blockprofilerate;
   627  void	runtime_addtimer(Timer*);
   628  bool	runtime_deltimer(Timer*);
   629  G*	runtime_netpoll(bool);
   630  void	runtime_netpollinit(void);
   631  int32	runtime_netpollopen(uintptr, PollDesc*);
   632  int32   runtime_netpollclose(uintptr);
   633  void	runtime_netpollready(G**, PollDesc*, int32);
   634  uintptr	runtime_netpollfd(PollDesc*);
   635  void	runtime_netpollarm(PollDesc*, int32);
   636  void**	runtime_netpolluser(PollDesc*);
   637  bool	runtime_netpollclosing(PollDesc*);
   638  void	runtime_netpolllock(PollDesc*);
   639  void	runtime_netpollunlock(PollDesc*);
   640  void	runtime_crash(void);
   641  void	runtime_parsedebugvars(void);
   642  void	_rt0_go(void);
   643  void*	runtime_funcdata(Func*, int32);
   644  int32	runtime_setmaxthreads(int32);
   645  G*	runtime_timejump(void);
   646  void	runtime_iterate_finq(void (*callback)(FuncVal*, void*, const FuncType*, const PtrType*));
   647  
   648  void	runtime_stoptheworld(void);
   649  void	runtime_starttheworld(void);
   650  extern uint32 runtime_worldsema;
   651  
   652  /*
   653   * mutual exclusion locks.  in the uncontended case,
   654   * as fast as spin locks (just a few user-level instructions),
   655   * but on the contention path they sleep in the kernel.
   656   * a zeroed Lock is unlocked (no need to initialize each lock).
   657   */
   658  void	runtime_lock(Lock*);
   659  void	runtime_unlock(Lock*);
   660  
   661  /*
   662   * sleep and wakeup on one-time events.
   663   * before any calls to notesleep or notewakeup,
   664   * must call noteclear to initialize the Note.
   665   * then, exactly one thread can call notesleep
   666   * and exactly one thread can call notewakeup (once).
   667   * once notewakeup has been called, the notesleep
   668   * will return.  future notesleep will return immediately.
   669   * subsequent noteclear must be called only after
   670   * previous notesleep has returned, e.g. it's disallowed
   671   * to call noteclear straight after notewakeup.
   672   *
   673   * notetsleep is like notesleep but wakes up after
   674   * a given number of nanoseconds even if the event
   675   * has not yet happened.  if a goroutine uses notetsleep to
   676   * wake up early, it must wait to call noteclear until it
   677   * can be sure that no other goroutine is calling
   678   * notewakeup.
   679   *
   680   * notesleep/notetsleep are generally called on g0,
   681   * notetsleepg is similar to notetsleep but is called on user g.
   682   */
   683  void	runtime_noteclear(Note*);
   684  void	runtime_notesleep(Note*);
   685  void	runtime_notewakeup(Note*);
   686  bool	runtime_notetsleep(Note*, int64);  // false - timeout
   687  bool	runtime_notetsleepg(Note*, int64);  // false - timeout
   688  
   689  /*
   690   * low-level synchronization for implementing the above
   691   */
   692  uintptr	runtime_semacreate(void);
   693  int32	runtime_semasleep(int64);
   694  void	runtime_semawakeup(M*);
   695  // or
   696  void	runtime_futexsleep(uint32*, uint32, int64);
   697  void	runtime_futexwakeup(uint32*, uint32);
   698  
   699  /*
   700   * Lock-free stack.
   701   * Initialize uint64 head to 0, compare with 0 to test for emptiness.
   702   * The stack does not keep pointers to nodes,
   703   * so they can be garbage collected if there are no other pointers to nodes.
   704   */
   705  void	runtime_lfstackpush(uint64 *head, LFNode *node)
   706    __asm__ (GOSYM_PREFIX "runtime.lfstackpush");
   707  LFNode*	runtime_lfstackpop(uint64 *head);
   708  
   709  /*
   710   * Parallel for over [0, n).
   711   * body() is executed for each iteration.
   712   * nthr - total number of worker threads.
   713   * ctx - arbitrary user context.
   714   * if wait=true, threads return from parfor() when all work is done;
   715   * otherwise, threads can return while other threads are still finishing processing.
   716   */
   717  ParFor*	runtime_parforalloc(uint32 nthrmax);
   718  void	runtime_parforsetup(ParFor *desc, uint32 nthr, uint32 n, void *ctx, bool wait, void (*body)(ParFor*, uint32));
   719  void	runtime_parfordo(ParFor *desc);
   720  void	runtime_parforiters(ParFor*, uintptr, uintptr*, uintptr*);
   721  
   722  /*
   723   * low level C-called
   724   */
   725  #define runtime_mmap mmap
   726  #define runtime_munmap munmap
   727  #define runtime_madvise madvise
   728  #define runtime_memclr(buf, size) __builtin_memset((buf), 0, (size))
   729  #define runtime_getcallerpc(p) __builtin_return_address(0)
   730  
   731  #ifdef __rtems__
   732  void __wrap_rtems_task_variable_add(void **);
   733  #endif
   734  
   735  /*
   736   * Names generated by gccgo.
   737   */
   738  #define runtime_printbool	__go_print_bool
   739  #define runtime_printfloat	__go_print_double
   740  #define runtime_printint	__go_print_int64
   741  #define runtime_printiface	__go_print_interface
   742  #define runtime_printeface	__go_print_empty_interface
   743  #define runtime_printstring	__go_print_string
   744  #define runtime_printpointer	__go_print_pointer
   745  #define runtime_printuint	__go_print_uint64
   746  #define runtime_printslice	__go_print_slice
   747  #define runtime_printcomplex	__go_print_complex
   748  
   749  /*
   750   * runtime go-called
   751   */
   752  void	runtime_printbool(_Bool);
   753  void	runtime_printbyte(int8);
   754  void	runtime_printfloat(double);
   755  void	runtime_printint(int64);
   756  void	runtime_printiface(Iface);
   757  void	runtime_printeface(Eface);
   758  void	runtime_printstring(String);
   759  void	runtime_printpc(void*);
   760  void	runtime_printpointer(void*);
   761  void	runtime_printuint(uint64);
   762  void	runtime_printhex(uint64);
   763  void	runtime_printslice(Slice);
   764  void	runtime_printcomplex(complex double);
   765  void reflect_call(const struct __go_func_type *, FuncVal *, _Bool, _Bool,
   766  		  void **, void **)
   767    __asm__ (GOSYM_PREFIX "reflect.call");
   768  #define runtime_panic __go_panic
   769  
   770  /*
   771   * runtime c-called (but written in Go)
   772   */
   773  void	runtime_printany(Eface)
   774       __asm__ (GOSYM_PREFIX "runtime.Printany");
   775  void	runtime_newTypeAssertionError(const String*, const String*, const String*, const String*, Eface*)
   776       __asm__ (GOSYM_PREFIX "runtime.NewTypeAssertionError");
   777  void	runtime_newErrorCString(const char*, Eface*)
   778       __asm__ (GOSYM_PREFIX "runtime.NewErrorCString");
   779  
   780  /*
   781   * wrapped for go users
   782   */
   783  void	runtime_semacquire(uint32 volatile *, bool);
   784  void	runtime_semrelease(uint32 volatile *);
   785  int32	runtime_gomaxprocsfunc(int32 n);
   786  void	runtime_procyield(uint32);
   787  void	runtime_osyield(void);
   788  void	runtime_lockOSThread(void);
   789  void	runtime_unlockOSThread(void);
   790  bool	runtime_lockedOSThread(void);
   791  
   792  bool	runtime_showframe(String, bool);
   793  void	runtime_printcreatedby(G*);
   794  
   795  uintptr	runtime_memlimit(void);
   796  
   797  #define ISNAN(f) __builtin_isnan(f)
   798  
   799  enum
   800  {
   801  	UseSpanType = 1,
   802  };
   803  
   804  #define runtime_setitimer setitimer
   805  
   806  void	runtime_check(void);
   807  
   808  // A list of global variables that the garbage collector must scan.
   809  struct root_list {
   810  	struct root_list *next;
   811  	struct root {
   812  		void *decl;
   813  		size_t size;
   814  	} roots[];
   815  };
   816  
   817  void	__go_register_gc_roots(struct root_list*);
   818  
   819  // Size of stack space allocated using Go's allocator.
   820  // This will be 0 when using split stacks, as in that case
   821  // the stacks are allocated by the splitstack library.
   822  extern uintptr runtime_stacks_sys;
   823  
   824  struct backtrace_state;
   825  extern struct backtrace_state *__go_get_backtrace_state(void);
   826  extern _Bool __go_file_line(uintptr, String*, String*, intgo *);
   827  extern byte* runtime_progname();
   828  extern void runtime_main(void*);
   829  extern uint32 runtime_in_callers;
   830  
   831  int32 getproccount(void);
   832  
   833  #define PREFETCH(p) __builtin_prefetch(p)
   834  
   835  bool	runtime_gcwaiting(void);
   836  void	runtime_badsignal(int);
   837  Defer*	runtime_newdefer(void);
   838  void	runtime_freedefer(Defer*);
   839  
   840  struct time_now_ret
   841  {
   842    int64_t sec;
   843    int32_t nsec;
   844  };
   845  
   846  struct time_now_ret now() __asm__ (GOSYM_PREFIX "time.now")
   847    __attribute__ ((no_split_stack));