diff options
author | Alex Brainman <alex.brainman@gmail.com> | 2014-11-13 14:53:13 +1100 |
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committer | Alex Brainman <alex.brainman@gmail.com> | 2014-11-13 14:53:13 +1100 |
commit | 6399eb54aaff5cc06643bcbbfa1b3dd24f743681 (patch) | |
tree | 4e0958e7915ea54c59612808d20f47f27f9fc7a5 /src/runtime | |
parent | 02a7c13f8e208ad8aabbed94522f4417e6f036e8 (diff) | |
download | go-6399eb54aaff5cc06643bcbbfa1b3dd24f743681.tar.gz |
[dev.cc] runtime: convert mem_windows.c to Go
LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/175000043
Diffstat (limited to 'src/runtime')
-rw-r--r-- | src/runtime/mem_windows.c | 132 | ||||
-rw-r--r-- | src/runtime/mem_windows.go | 119 |
2 files changed, 119 insertions, 132 deletions
diff --git a/src/runtime/mem_windows.c b/src/runtime/mem_windows.c deleted file mode 100644 index 6ea992020..000000000 --- a/src/runtime/mem_windows.c +++ /dev/null @@ -1,132 +0,0 @@ -// Copyright 2010 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -#include "runtime.h" -#include "arch_GOARCH.h" -#include "os_GOOS.h" -#include "defs_GOOS_GOARCH.h" -#include "malloc.h" -#include "textflag.h" - -enum { - MEM_COMMIT = 0x1000, - MEM_RESERVE = 0x2000, - MEM_DECOMMIT = 0x4000, - MEM_RELEASE = 0x8000, - - PAGE_READWRITE = 0x0004, - PAGE_NOACCESS = 0x0001, -}; - -#pragma dynimport runtime·VirtualAlloc VirtualAlloc "kernel32.dll" -#pragma dynimport runtime·VirtualFree VirtualFree "kernel32.dll" -#pragma dynimport runtime·VirtualProtect VirtualProtect "kernel32.dll" -extern void *runtime·VirtualAlloc; -extern void *runtime·VirtualFree; -extern void *runtime·VirtualProtect; - -#pragma textflag NOSPLIT -void* -runtime·sysAlloc(uintptr n, uint64 *stat) -{ - runtime·xadd64(stat, n); - return runtime·stdcall4(runtime·VirtualAlloc, 0, n, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE); -} - -void -runtime·SysUnused(void *v, uintptr n) -{ - void *r; - uintptr small; - - r = runtime·stdcall3(runtime·VirtualFree, (uintptr)v, n, MEM_DECOMMIT); - if(r != nil) - return; - - // Decommit failed. Usual reason is that we've merged memory from two different - // VirtualAlloc calls, and Windows will only let each VirtualFree handle pages from - // a single VirtualAlloc. It is okay to specify a subset of the pages from a single alloc, - // just not pages from multiple allocs. This is a rare case, arising only when we're - // trying to give memory back to the operating system, which happens on a time - // scale of minutes. It doesn't have to be terribly fast. Instead of extra bookkeeping - // on all our VirtualAlloc calls, try freeing successively smaller pieces until - // we manage to free something, and then repeat. This ends up being O(n log n) - // in the worst case, but that's fast enough. - while(n > 0) { - small = n; - while(small >= 4096 && runtime·stdcall3(runtime·VirtualFree, (uintptr)v, small, MEM_DECOMMIT) == nil) - small = (small / 2) & ~(4096-1); - if(small < 4096) - runtime·throw("runtime: failed to decommit pages"); - v = (byte*)v + small; - n -= small; - } -} - -void -runtime·SysUsed(void *v, uintptr n) -{ - void *r; - uintptr small; - - r = runtime·stdcall4(runtime·VirtualAlloc, (uintptr)v, n, MEM_COMMIT, PAGE_READWRITE); - if(r != v) - runtime·throw("runtime: failed to commit pages"); - - // Commit failed. See SysUnused. - while(n > 0) { - small = n; - while(small >= 4096 && runtime·stdcall4(runtime·VirtualAlloc, (uintptr)v, small, MEM_COMMIT, PAGE_READWRITE) == nil) - small = (small / 2) & ~(4096-1); - if(small < 4096) - runtime·throw("runtime: failed to decommit pages"); - v = (byte*)v + small; - n -= small; - } -} - -void -runtime·SysFree(void *v, uintptr n, uint64 *stat) -{ - uintptr r; - - runtime·xadd64(stat, -(uint64)n); - r = (uintptr)runtime·stdcall3(runtime·VirtualFree, (uintptr)v, 0, MEM_RELEASE); - if(r == 0) - runtime·throw("runtime: failed to release pages"); -} - -void -runtime·SysFault(void *v, uintptr n) -{ - // SysUnused makes the memory inaccessible and prevents its reuse - runtime·SysUnused(v, n); -} - -void* -runtime·SysReserve(void *v, uintptr n, bool *reserved) -{ - *reserved = true; - // v is just a hint. - // First try at v. - v = runtime·stdcall4(runtime·VirtualAlloc, (uintptr)v, n, MEM_RESERVE, PAGE_READWRITE); - if(v != nil) - return v; - - // Next let the kernel choose the address. - return runtime·stdcall4(runtime·VirtualAlloc, 0, n, MEM_RESERVE, PAGE_READWRITE); -} - -void -runtime·SysMap(void *v, uintptr n, bool reserved, uint64 *stat) -{ - void *p; - - USED(reserved); - - runtime·xadd64(stat, n); - p = runtime·stdcall4(runtime·VirtualAlloc, (uintptr)v, n, MEM_COMMIT, PAGE_READWRITE); - if(p != v) - runtime·throw("runtime: cannot map pages in arena address space"); -} diff --git a/src/runtime/mem_windows.go b/src/runtime/mem_windows.go new file mode 100644 index 000000000..a1dcad013 --- /dev/null +++ b/src/runtime/mem_windows.go @@ -0,0 +1,119 @@ +// Copyright 2010 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package runtime + +import ( + "unsafe" +) + +const ( + _MEM_COMMIT = 0x1000 + _MEM_RESERVE = 0x2000 + _MEM_DECOMMIT = 0x4000 + _MEM_RELEASE = 0x8000 + + _PAGE_READWRITE = 0x0004 + _PAGE_NOACCESS = 0x0001 +) + +//go:cgo_import_dynamic runtime._VirtualAlloc VirtualAlloc "kernel32.dll" +//go:cgo_import_dynamic runtime._VirtualFree VirtualFree "kernel32.dll" +//go:cgo_import_dynamic runtime._VirtualProtect VirtualProtect "kernel32.dll" + +var ( + _VirtualAlloc, + _VirtualFree, + _VirtualProtect stdFunction +) + +//go:nosplit +func sysAlloc(n uintptr, stat *uint64) unsafe.Pointer { + xadd64(stat, int64(n)) + return unsafe.Pointer(stdcall4(_VirtualAlloc, 0, n, _MEM_COMMIT|_MEM_RESERVE, _PAGE_READWRITE)) +} + +func sysUnused(v unsafe.Pointer, n uintptr) { + r := stdcall3(_VirtualFree, uintptr(v), n, _MEM_DECOMMIT) + if r != 0 { + return + } + + // Decommit failed. Usual reason is that we've merged memory from two different + // VirtualAlloc calls, and Windows will only let each VirtualFree handle pages from + // a single VirtualAlloc. It is okay to specify a subset of the pages from a single alloc, + // just not pages from multiple allocs. This is a rare case, arising only when we're + // trying to give memory back to the operating system, which happens on a time + // scale of minutes. It doesn't have to be terribly fast. Instead of extra bookkeeping + // on all our VirtualAlloc calls, try freeing successively smaller pieces until + // we manage to free something, and then repeat. This ends up being O(n log n) + // in the worst case, but that's fast enough. + for n > 0 { + small := n + for small >= 4096 && stdcall3(_VirtualFree, uintptr(v), small, _MEM_DECOMMIT) == 0 { + small /= 2 + small &^= 4096 - 1 + } + if small < 4096 { + gothrow("runtime: failed to decommit pages") + } + v = add(v, small) + n -= small + } +} + +func sysUsed(v unsafe.Pointer, n uintptr) { + r := stdcall4(_VirtualAlloc, uintptr(v), n, _MEM_COMMIT, _PAGE_READWRITE) + if r != uintptr(v) { + gothrow("runtime: failed to commit pages") + } + + // Commit failed. See SysUnused. + for n > 0 { + small := n + for small >= 4096 && stdcall4(_VirtualAlloc, uintptr(v), small, _MEM_COMMIT, _PAGE_READWRITE) == 0 { + small /= 2 + small &^= 4096 - 1 + } + if small < 4096 { + gothrow("runtime: failed to decommit pages") + } + v = add(v, small) + n -= small + } +} + +func sysFree(v unsafe.Pointer, n uintptr, stat *uint64) { + xadd64(stat, -int64(n)) + r := stdcall3(_VirtualFree, uintptr(v), 0, _MEM_RELEASE) + if r == 0 { + gothrow("runtime: failed to release pages") + } +} + +func sysFault(v unsafe.Pointer, n uintptr) { + // SysUnused makes the memory inaccessible and prevents its reuse + sysUnused(v, n) +} + +func sysReserve(v unsafe.Pointer, n uintptr, reserved *bool) unsafe.Pointer { + *reserved = true + // v is just a hint. + // First try at v. + v = unsafe.Pointer(stdcall4(_VirtualAlloc, uintptr(v), n, _MEM_RESERVE, _PAGE_READWRITE)) + if v != nil { + return v + } + + // Next let the kernel choose the address. + return unsafe.Pointer(stdcall4(_VirtualAlloc, 0, n, _MEM_RESERVE, _PAGE_READWRITE)) +} + +func sysMap(v unsafe.Pointer, n uintptr, reserved bool, stat *uint64) { + xadd64(stat, int64(n)) + p := stdcall4(_VirtualAlloc, uintptr(v), n, _MEM_COMMIT, _PAGE_READWRITE) + if p != uintptr(v) { + gothrow("runtime: cannot map pages in arena address space") + } +} |