projects / apple / security.git / blame
| Commit | Line | Data |
|---|---|---|
| bac41a7b A |
1 | /* |
| 2 | * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. | |
| 3 | * | |
| 4 | * The contents of this file constitute Original Code as defined in and are | |
| 5 | * subject to the Apple Public Source License Version 1.2 (the 'License'). | |
| 6 | * You may not use this file except in compliance with the License. Please obtain | |
| 7 | * a copy of the License at http://www.apple.com/publicsource and read it before | |
| 8 | * using this file. | |
| 9 | * | |
| 10 | * This Original Code and all software distributed under the License are | |
| 11 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS | |
| 12 | * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT | |
| 13 | * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR | |
| 14 | * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the | |
| 15 | * specific language governing rights and limitations under the License. | |
| 16 | */ | |
| 17 | ||
| 18 | ||
| 19 | // | |
| 20 | // threading_internal - internal support classes and functions for threading implementation | |
| 21 | // | |
| 22 | #ifndef _H_THREADING_INTERNAL | |
| 23 | #define _H_THREADING_INTERNAL | |
| 24 | ||
| 25 | #include <Security/utilities.h> | |
| 26 | ||
| 27 | ||
| 28 | namespace Security { | |
| 29 | ||
| 30 | ||
| 31 | // | |
| 32 | // Architecture-specific atomic operation primitives. | |
| 33 | // AtomicWord is an integer type that works with these; | |
| 34 | // we'll assume that a pointer fits into it (using reinterpret_cast). | |
| 35 | // | |
| 36 | #if TARGET_CPU_PPC | |
| 37 | ||
| 38 | #define _HAVE_ATOMIC_OPERATIONS | |
| 39 | ||
| 40 | typedef unsigned int AtomicWord; | |
| 41 | ||
| 42 | inline AtomicWord atomicLoad(AtomicWord &atom) | |
| 43 | { | |
| 44 | AtomicWord result; | |
| 45 | asm volatile ( | |
| 46 | "0: lwarx %0,0,%1 \n" | |
| 47 | " stwcx. %0,0,%1 \n" | |
| 48 | " bne- 0b" | |
| 49 | : "=&r"(result) | |
| 50 | : "b"(&atom) | |
| 51 | : "cc" | |
| 52 | ); | |
| 53 | return result; | |
| 54 | } | |
| 55 | ||
| 56 | inline AtomicWord atomicStore(AtomicWord &atom, AtomicWord newValue, AtomicWord oldValue) | |
| 57 | { | |
| 58 | register bool result; | |
| 59 | asm volatile ( | |
| 60 | "0: lwarx %0,0,%1 \n" // load and reserve -> %0 | |
| 61 | " cmpw %0,%3 \n" // compare to old | |
| 62 | " bne 1f \n" // fail if not equal | |
| 63 | " stwcx. %2,0,%1 \n" // store and check | |
| 64 | " bne 0b \n" // retry if contended | |
| 65 | "1: " | |
| 66 | : "=&r"(result) | |
| 67 | : "b"(&atom), "r"(newValue), "r"(oldValue) | |
| 68 | : "cc" | |
| 69 | ); | |
| 70 | return result; | |
| 71 | } | |
| 72 | ||
| 73 | inline AtomicWord atomicOffset(AtomicWord &atom, int offset) | |
| 74 | { | |
| 75 | AtomicWord result; | |
| 76 | asm volatile ( | |
| 77 | "0: lwarx %0,0,%1 \n" | |
| 78 | " add %0,%0,%2 \n" | |
| 79 | " stwcx. %0,0,%1 \n" | |
| 80 | " bne- 0b" | |
| 81 | : "=&r"(result) | |
| 82 | : "b"(&atom), "r"(offset) | |
| 83 | : "cc" | |
| 84 | ); | |
| 85 | return result; | |
| 86 | } | |
| 87 | ||
| 88 | inline AtomicWord atomicIncrement(AtomicWord &atom) | |
| 89 | { return atomicOffset(atom, +1); } | |
| 90 | ||
| 91 | inline AtomicWord atomicDecrement(AtomicWord &atom) | |
| 92 | { return atomicOffset(atom, -1); } | |
| 93 | ||
| 94 | #endif //TARGET_CPU_PPC | |
| 95 | ||
| 96 | } // end namespace Security | |
| 97 | ||
| 98 | #endif //_H_THREADING_INTERNAL |