runtime: implement pprof support for windows

Credit to jp for proof of concept.

R=alex.brainman, jp, rsc, dvyukov
CC=golang-dev
https://golang.org/cl/4960057

src/pkg/runtime/runtime.h

@@ -212,6 +212,7 @@ struct	G
 	uintptr	sigcode1;
 	uintptr	sigpc;
 	uintptr	gopc;	// pc of go statement that created this goroutine
+	uintptr	end[];
 };
 struct	M
 {
@@ -253,9 +254,11 @@ struct	M
 	uint32	fflag;		// floating point compare flags
 
 #ifdef __WINDOWS__
+	void*	thread;		// thread handle
 	void*	event;		// event for signalling
 	M*	nextwaitm;	// next M waiting for lock
 #endif
+	uintptr	end[];
 };
 
 struct	Stktop

src/pkg/runtime/windows/386/defs.h

@@ -10,9 +10,13 @@ enum {
 	PROT_EXEC = 0x4,
 	MAP_ANON = 0x1,
 	MAP_PRIVATE = 0x2,
+	DUPLICATE_SAME_ACCESS = 0x2,
+	THREAD_PRIORITY_HIGHEST = 0x2,
 	SIGINT = 0x2,
 	CTRL_C_EVENT = 0,
 	CTRL_BREAK_EVENT = 0x1,
+	CONTEXT_CONTROL = 0x10001,
+	CONTEXT_FULL = 0x10007,
 	EXCEPTION_ACCESS_VIOLATION = 0xc0000005,
 	EXCEPTION_BREAKPOINT = 0x80000003,
 	EXCEPTION_FLT_DENORMAL_OPERAND = 0xc000008d,

src/pkg/runtime/windows/386/signal.c

@@ -90,9 +90,7 @@ runtime·sighandler(ExceptionRecord *info, void *frame, Context *r)
 }
 
 void
-runtime·resetcpuprofiler(int32 hz)
+runtime·dosigprof(Context *r, G *gp)
 {
-	// TODO: Enable profiling interrupts.
-
-	m->profilehz = hz;
+	runtime·sigprof((uint8*)r->Eip, (uint8*)r->Esp, nil, gp);
 }

src/pkg/runtime/windows/386/sys.s

@@ -96,31 +96,52 @@ TEXT runtime·sigtramp1(SB),0,$16-40
 sigdone:
 	RET
 
-// Windows runs the ctrl handler in a new thread.
 TEXT runtime·ctrlhandler(SB),7,$0
+	PUSHL	$runtime·ctrlhandler1(SB)
+	CALL	runtime·externalthreadhandler(SB)
+	MOVL	4(SP), CX
+	ADDL	$12, SP
+	JMP	CX
+
+TEXT runtime·profileloop(SB),7,$0
+	PUSHL	$runtime·profileloop1(SB)
+	CALL	runtime·externalthreadhandler(SB)
+	MOVL	4(SP), CX
+	ADDL	$12, SP
+	JMP	CX
+
+TEXT runtime·externalthreadhandler(SB),7,$0
 	PUSHL	BP
 	MOVL	SP, BP
 	PUSHL	BX
 	PUSHL	SI
 	PUSHL	DI
 	PUSHL	0x2c(FS)
-	MOVL	SP, BX
+	MOVL	SP, DX
 
 	// setup dummy m, g
-	SUBL	$(m_fflag+4), SP	// at least space for m_fflag
+	SUBL	$m_end, SP		// space for M
+	MOVL	SP, 0(SP)
+	MOVL	$m_end, 4(SP)
+	CALL	runtime·memclr(SB)	// smashes AX,BX,CX
+
 	LEAL	m_tls(SP), CX
 	MOVL	CX, 0x2c(FS)
 	MOVL	SP, m(CX)
-	MOVL	SP, DX
-	SUBL	$8, SP			// space for g_stack{guard,base}
+	MOVL	SP, BX
+	SUBL	$g_end, SP		// space for G
 	MOVL	SP, g(CX)
-	MOVL	SP, m_g0(DX)
+	MOVL	SP, m_g0(BX)
+
+	MOVL	SP, 0(SP)
+	MOVL	$g_end, 4(SP)
+	CALL	runtime·memclr(SB)	// smashes AX,BX,CX
 	LEAL	-4096(SP), CX
 	MOVL	CX, g_stackguard(SP)
-	MOVL	BX, g_stackbase(SP)
+	MOVL	DX, g_stackbase(SP)
 
-	PUSHL	8(BP)
-	CALL	runtime·ctrlhandler1(SB)
+	PUSHL	16(BP)			// arg for handler
+	CALL	8(BP)
 	POPL	CX
 
 	get_tls(CX)
@@ -131,9 +152,7 @@ TEXT runtime·ctrlhandler(SB),7,$0
 	POPL	SI
 	POPL	BX
 	POPL	BP
-	MOVL	0(SP), CX
-	ADDL	$8, SP
-	JMP	CX
+	RET
 
 // Called from dynamic function created by ../thread.c compilecallback,
 // running on Windows stack (not Go stack).

src/pkg/runtime/windows/amd64/defs.h

@@ -10,9 +10,13 @@ enum {
 	PROT_EXEC = 0x4,
 	MAP_ANON = 0x1,
 	MAP_PRIVATE = 0x2,
+	DUPLICATE_SAME_ACCESS = 0x2,
+	THREAD_PRIORITY_HIGHEST = 0x2,
 	SIGINT = 0x2,
 	CTRL_C_EVENT = 0,
 	CTRL_BREAK_EVENT = 0x1,
+	CONTEXT_CONTROL = 0x100001,
+	CONTEXT_FULL = 0x10000b,
 	EXCEPTION_ACCESS_VIOLATION = 0xc0000005,
 	EXCEPTION_BREAKPOINT = 0x80000003,
 	EXCEPTION_FLT_DENORMAL_OPERAND = 0xc000008d,

src/pkg/runtime/windows/amd64/signal.c

@@ -100,9 +100,7 @@ runtime·sighandler(ExceptionRecord *info, Context *r, G *gp)
 }
 
 void
-runtime·resetcpuprofiler(int32 hz)
+runtime·dosigprof(Context *r, G *gp)
 {
-	// TODO: Enable profiling interrupts.
-
-	m->profilehz = hz;
+	runtime·sigprof((uint8*)r->Rip, (uint8*)r->Rsp, nil, gp);
 }

src/pkg/runtime/windows/amd64/sys.s

@@ -100,31 +100,51 @@ TEXT runtime·sigtramp(SB),7,$56
 sigdone:
 	RET
 
-// Windows runs the ctrl handler in a new thread.
-TEXT runtime·ctrlhandler(SB),7,$0
+TEXT runtime·ctrlhandler(SB),7,$8
+	MOVQ	CX, 16(SP)		// spill
+	MOVQ	$runtime·ctrlhandler1(SB), CX
+	MOVQ	CX, 0(SP)
+	CALL	runtime·externalthreadhandler(SB)
+	RET
+
+TEXT runtime·profileloop(SB),7,$8
+	MOVQ	$runtime·profileloop1(SB), CX
+	MOVQ	CX, 0(SP)
+	CALL	runtime·externalthreadhandler(SB)
+	RET
+
+TEXT runtime·externalthreadhandler(SB),7,$0
 	PUSHQ	BP
 	MOVQ	SP, BP
 	PUSHQ	BX
 	PUSHQ	SI
 	PUSHQ	DI
 	PUSHQ	0x58(GS)
-	MOVQ	SP, BX
+	MOVQ	SP, DX
 
 	// setup dummy m, g
-	SUBQ	$(m_fflag+4), SP	// at least space for m_fflag
+	SUBQ	$m_end, SP		// space for M
+	MOVQ	SP, 0(SP)
+	MOVQ	$m_end, 8(SP)
+	CALL	runtime·memclr(SB)	// smashes AX,BX,CX
+
 	LEAQ	m_tls(SP), CX
 	MOVQ	CX, 0x58(GS)
 	MOVQ	SP, m(CX)
-	MOVQ	SP, DX
-	SUBQ	$16, SP			// space for g_stack{guard,base}
+	MOVQ	SP, BX
+	SUBQ	$g_end, SP		// space for G
 	MOVQ	SP, g(CX)
-	MOVQ	SP, m_g0(DX)
+	MOVQ	SP, m_g0(BX)
+
+	MOVQ	SP, 0(SP)
+	MOVQ	$g_end, 8(SP)
+	CALL	runtime·memclr(SB)	// smashes AX,BX,CX
 	LEAQ	-8192(SP), CX
 	MOVQ	CX, g_stackguard(SP)
-	MOVQ	BX, g_stackbase(SP)
+	MOVQ	DX, g_stackbase(SP)
 
-	PUSHQ	16(BP)
-	CALL	runtime·ctrlhandler1(SB)
+	PUSHQ	32(BP)			// arg for handler
+	CALL	16(BP)
 	POPQ	CX
 
 	get_tls(CX)

src/pkg/runtime/windows/defs.c

@@ -17,10 +17,16 @@ enum {
 	$MAP_ANON = 1,
 	$MAP_PRIVATE = 2,
 
+	$DUPLICATE_SAME_ACCESS = DUPLICATE_SAME_ACCESS,
+	$THREAD_PRIORITY_HIGHEST = THREAD_PRIORITY_HIGHEST,
+
 	$SIGINT = SIGINT,
 	$CTRL_C_EVENT = CTRL_C_EVENT,
 	$CTRL_BREAK_EVENT = CTRL_BREAK_EVENT,
 
+	$CONTEXT_CONTROL = CONTEXT_CONTROL,
+	$CONTEXT_FULL = CONTEXT_FULL,
+
 	$EXCEPTION_ACCESS_VIOLATION = STATUS_ACCESS_VIOLATION,
 	$EXCEPTION_BREAKPOINT = STATUS_BREAKPOINT,
 	$EXCEPTION_FLT_DENORMAL_OPERAND = STATUS_FLOAT_DENORMAL_OPERAND,

src/pkg/runtime/windows/os.h

@@ -13,8 +13,8 @@ extern void *runtime·GetProcAddress;
 void runtime·asmstdcall(void *c);
 void *runtime·stdcall(void *fn, int32 count, ...);
 
-uintptr runtime·getlasterror(void);
-void runtime·setlasterror(uintptr err);
+uint32 runtime·getlasterror(void);
+void runtime·setlasterror(uint32 err);
 
 // Function to be called by windows CreateThread
 // to start new os thread.