Squash: Fix bugs

trunk/3rdparty/gperftools-2-fit/src/emergency_malloc.cc

@@ -0,0 +1,169 @@
+// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
+// Copyright (c) 2014, gperftools Contributors
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+
+#include "config.h"
+
+#include "emergency_malloc.h"
+
+#include <errno.h>                      // for ENOMEM, errno
+#include <string.h>                     // for memset
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/low_level_alloc.h"
+#include "base/spinlock.h"
+#include "internal_logging.h"
+
+
+namespace tcmalloc {
+  __attribute__ ((visibility("internal"))) char *emergency_arena_start;
+  __attribute__ ((visibility("internal"))) uintptr_t emergency_arena_start_shifted;
+
+  static CACHELINE_ALIGNED SpinLock emergency_malloc_lock(base::LINKER_INITIALIZED);
+  static char *emergency_arena_end;
+  static LowLevelAlloc::Arena *emergency_arena;
+
+  class EmergencyArenaPagesAllocator : public LowLevelAlloc::PagesAllocator {
+    ~EmergencyArenaPagesAllocator() {}
+    void *MapPages(int32 flags, size_t size) {
+      char *new_end = emergency_arena_end + size;
+      if (new_end > emergency_arena_start + kEmergencyArenaSize) {
+        RAW_LOG(FATAL, "Unable to allocate %zu bytes in emergency zone.", size);
+      }
+      char *rv = emergency_arena_end;
+      emergency_arena_end = new_end;
+      return static_cast<void *>(rv);
+    }
+    void UnMapPages(int32 flags, void *addr, size_t size) {
+      RAW_LOG(FATAL, "UnMapPages is not implemented for emergency arena");
+    }
+  };
+
+  static union {
+    char bytes[sizeof(EmergencyArenaPagesAllocator)];
+    void *ptr;
+  } pages_allocator_place;
+
+  static void InitEmergencyMalloc(void) {
+    const int32 flags = LowLevelAlloc::kAsyncSignalSafe;
+
+    void *arena = LowLevelAlloc::GetDefaultPagesAllocator()->MapPages(flags, kEmergencyArenaSize * 2);
+
+    uintptr_t arena_ptr = reinterpret_cast<uintptr_t>(arena);
+    uintptr_t ptr = (arena_ptr + kEmergencyArenaSize - 1) & ~(kEmergencyArenaSize-1);
+
+    emergency_arena_end = emergency_arena_start = reinterpret_cast<char *>(ptr);
+    EmergencyArenaPagesAllocator *allocator = new (pages_allocator_place.bytes) EmergencyArenaPagesAllocator();
+    emergency_arena = LowLevelAlloc::NewArenaWithCustomAlloc(0, LowLevelAlloc::DefaultArena(), allocator);
+
+    emergency_arena_start_shifted = reinterpret_cast<uintptr_t>(emergency_arena_start) >> kEmergencyArenaShift;
+
+    uintptr_t head_unmap_size = ptr - arena_ptr;
+    CHECK_CONDITION(head_unmap_size < kEmergencyArenaSize);
+    if (head_unmap_size != 0) {
+      LowLevelAlloc::GetDefaultPagesAllocator()->UnMapPages(flags, arena, ptr - arena_ptr);
+    }
+
+    uintptr_t tail_unmap_size = kEmergencyArenaSize - head_unmap_size;
+    void *tail_start = reinterpret_cast<void *>(arena_ptr + head_unmap_size + kEmergencyArenaSize);
+    LowLevelAlloc::GetDefaultPagesAllocator()->UnMapPages(flags, tail_start, tail_unmap_size);
+  }
+
+  PERFTOOLS_DLL_DECL void *EmergencyMalloc(size_t size) {
+    SpinLockHolder l(&emergency_malloc_lock);
+
+    if (emergency_arena_start == NULL) {
+      InitEmergencyMalloc();
+      CHECK_CONDITION(emergency_arena_start != NULL);
+    }
+
+    void *rv = LowLevelAlloc::AllocWithArena(size, emergency_arena);
+    if (rv == NULL) {
+      errno = ENOMEM;
+    }
+    return rv;
+  }
+
+  PERFTOOLS_DLL_DECL void EmergencyFree(void *p) {
+    SpinLockHolder l(&emergency_malloc_lock);
+    if (emergency_arena_start == NULL) {
+      InitEmergencyMalloc();
+      CHECK_CONDITION(emergency_arena_start != NULL);
+      free(p);
+      return;
+    }
+    CHECK_CONDITION(emergency_arena_start);
+    LowLevelAlloc::Free(p);
+  }
+
+  PERFTOOLS_DLL_DECL void *EmergencyRealloc(void *_old_ptr, size_t new_size) {
+    if (_old_ptr == NULL) {
+      return EmergencyMalloc(new_size);
+    }
+    if (new_size == 0) {
+      EmergencyFree(_old_ptr);
+      return NULL;
+    }
+    SpinLockHolder l(&emergency_malloc_lock);
+    CHECK_CONDITION(emergency_arena_start);
+
+    char *old_ptr = static_cast<char *>(_old_ptr);
+    CHECK_CONDITION(old_ptr <= emergency_arena_end);
+    CHECK_CONDITION(emergency_arena_start <= old_ptr);
+
+    // NOTE: we don't know previous size of old_ptr chunk. So instead
+    // of trying to figure out right size of copied memory, we just
+    // copy largest possible size. We don't care about being slow.
+    size_t old_ptr_size = emergency_arena_end - old_ptr;
+    size_t copy_size = (new_size < old_ptr_size) ? new_size : old_ptr_size;
+
+    void *new_ptr = LowLevelAlloc::AllocWithArena(new_size, emergency_arena);
+    if (new_ptr == NULL) {
+      errno = ENOMEM;
+      return NULL;
+    }
+    memcpy(new_ptr, old_ptr, copy_size);
+
+    LowLevelAlloc::Free(old_ptr);
+    return new_ptr;
+  }
+
+  PERFTOOLS_DLL_DECL void *EmergencyCalloc(size_t n, size_t elem_size) {
+    // Overflow check
+    const size_t size = n * elem_size;
+    if (elem_size != 0 && size / elem_size != n) return NULL;
+    void *rv = EmergencyMalloc(size);
+    if (rv != NULL) {
+      memset(rv, 0, size);
+    }
+    return rv;
+  }
+};