runtime: copy internal locking code from Go 1.7 runtime

    
    Remove the old locking code written in C.
    
    Add a shell script mkrsysinfo.sh to generate the runtime_sysinfo.go
    file, so that we can get Go copies of the system time structures and
    other types.
    
    Tweak the compiler so that when compiling the runtime package the
    address operator does not cause local variables to escape.  When the gc
    compiler compiles the runtime, an escaping local variable is treated as
    an error.  We should implement that, instead of this change, when escape
    analysis is turned on.
    
    Tweak the compiler so that the generated C header does not include names
    that start with an underscore followed by a non-upper-case letter,
    except for the special cases of _defer and _panic.  Otherwise we
    translate C types to Go in runtime_sysinfo.go and then generate those Go
    types back as C types in runtime.inc, which is useless and painful for
    the C code.
    
    Change entersyscall and friends to take a dummy argument, as the gc
    versions do, to simplify calls from the shared code.
    
    Reviewed-on: https://go-review.googlesource.com/30079

From-SVN: r240657

1 files changed, 0 insertions, 58 deletions

diff --git a/libgo/runtime/thread-linux.c b/libgo/runtime/thread-linux.c
index ae56261..63a2b75 100644
--- a/libgo/runtime/thread-linux.c
+++ b/libgo/runtime/thread-linux.c
@@ -7,69 +7,11 @@
 #include "signal_unix.h"
 
 // Linux futex.
-//
-//	futexsleep(uint32 *addr, uint32 val)
-//	futexwakeup(uint32 *addr)
-//
-// Futexsleep atomically checks if *addr == val and if so, sleeps on addr.
-// Futexwakeup wakes up threads sleeping on addr.
-// Futexsleep is allowed to wake up spuriously.
 
-#include <errno.h>
-#include <string.h>
-#include <time.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
 #include <unistd.h>
 #include <syscall.h>
 #include <linux/futex.h>
 
-typedef struct timespec Timespec;
-
-// Atomically,
-//	if(*addr == val) sleep
-// Might be woken up spuriously; that's allowed.
-// Don't sleep longer than ns; ns < 0 means forever.
-void
-runtime_futexsleep(uint32 *addr, uint32 val, int64 ns)
-{
-	Timespec ts;
-	int32 nsec;
-
-	// Some Linux kernels have a bug where futex of
-	// FUTEX_WAIT returns an internal error code
-	// as an errno.  Libpthread ignores the return value
-	// here, and so can we: as it says a few lines up,
-	// spurious wakeups are allowed.
-
-	if(ns < 0) {
-		syscall(__NR_futex, addr, FUTEX_WAIT, val, nil, nil, 0);
-		return;
-	}
-	ts.tv_sec = runtime_timediv(ns, 1000000000LL, &nsec);
-	ts.tv_nsec = nsec;
-	syscall(__NR_futex, addr, FUTEX_WAIT, val, &ts, nil, 0);
-}
-
-// If any procs are sleeping on addr, wake up at most cnt.
-void
-runtime_futexwakeup(uint32 *addr, uint32 cnt)
-{
-	int64 ret;
-
-	ret = syscall(__NR_futex, addr, FUTEX_WAKE, cnt, nil, nil, 0);
-
-	if(ret >= 0)
-		return;
-
-	// I don't know that futex wakeup can return
-	// EAGAIN or EINTR, but if it does, it would be
-	// safe to loop and call futex again.
-	runtime_printf("futexwakeup addr=%p returned %D\n", addr, ret);
-	*(int32*)0x1006 = 0x1006;
-}
-
 void
 runtime_osinit(void)
 {