196 lines
6.6 KiB
Plaintext
196 lines
6.6 KiB
Plaintext
// Filename: atomicAdjustI386Impl.I
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// Created by: drose (01Apr06)
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//
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////////////////////////////////////////////////////////////////////
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//
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// PANDA 3D SOFTWARE
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// Copyright (c) 2001 - 2004, Disney Enterprises, Inc. All rights reserved
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//
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// All use of this software is subject to the terms of the Panda 3d
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// Software license. You should have received a copy of this license
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// along with this source code; you will also find a current copy of
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// the license at http://etc.cmu.edu/panda3d/docs/license/ .
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//
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// To contact the maintainers of this program write to
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// panda3d-general@lists.sourceforge.net .
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//
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////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::inc
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// Access: Public, Static
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// Description: Atomically increments the indicated variable.
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////////////////////////////////////////////////////////////////////
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INLINE void AtomicAdjustI386Impl::
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inc(TVOLATILE PN_int32 &var) {
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#ifdef _M_IX86
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// Windows case
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TVOLATILE PN_int32 *var_ptr = &var;
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__asm {
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mov edx, var_ptr;
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lock inc dword ptr [edx];
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}
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#elif !defined(__EDG__)
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// GCC case
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__asm__ __volatile__("lock; incl %0"
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:"=m" (var)
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:"m" (&var));
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#endif // __EDG__
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::dec
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// Access: Public, Static
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// Description: Atomically decrements the indicated variable and
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// returns true if the new value is nonzero, false if it
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// is zero.
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////////////////////////////////////////////////////////////////////
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INLINE bool AtomicAdjustI386Impl::
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dec(TVOLATILE PN_int32 &var) {
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unsigned char c;
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#ifdef _M_IX86
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// Windows case
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TVOLATILE PN_int32 *var_ptr = &var;
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__asm {
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mov edx, var_ptr;
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lock dec dword ptr [edx];
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sete c;
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}
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#elif !defined(__EDG__)
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// GCC case
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__asm__ __volatile__("lock; decl %0; sete %1"
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:"=m" (var), "=qm" (c)
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:"m" (&var) : "memory");
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#endif // __EDG__
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return (c == 0);
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::set
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// Access: Public, Static
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// Description: Atomically changes the indicated variable and
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// returns the original value.
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////////////////////////////////////////////////////////////////////
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INLINE PN_int32 AtomicAdjustI386Impl::
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set(TVOLATILE PN_int32 &var, PN_int32 new_value) {
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PN_int32 orig_value = var;
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var = new_value;
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return orig_value;
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::get
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// Access: Public, Static
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// Description: Atomically retrieves the snapshot value of the
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// indicated variable. This is the only guaranteed safe
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// way to retrieve the value that other threads might be
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// asynchronously setting, incrementing, or decrementing
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// (via other AtomicAjust methods).
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////////////////////////////////////////////////////////////////////
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INLINE PN_int32 AtomicAdjustI386Impl::
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get(const TVOLATILE PN_int32 &var) {
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return var;
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::set_ptr
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// Access: Public, Static
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// Description: Atomically changes the indicated variable and
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// returns the original value.
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////////////////////////////////////////////////////////////////////
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INLINE void *AtomicAdjustI386Impl::
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set_ptr(void * TVOLATILE &var, void *new_value) {
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void *orig_value = var;
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var = new_value;
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return orig_value;
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::get_ptr
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// Access: Public, Static
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// Description: Atomically retrieves the snapshot value of the
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// indicated variable. This is the only guaranteed safe
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// way to retrieve the value that other threads might be
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// asynchronously setting, incrementing, or decrementing
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// (via other AtomicAjust methods).
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////////////////////////////////////////////////////////////////////
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INLINE void *AtomicAdjustI386Impl::
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get_ptr(void * const TVOLATILE &var) {
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return var;
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::compare_and_exchange
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// Access: Public, Static
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// Description: Atomic compare and exchange.
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//
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// If mem is equal to old_value, store new_value in mem.
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// In either case, return the original value of mem.
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// The caller can test for success by comparing
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// return_value == old_value.
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//
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// The atomic function expressed in pseudo-code:
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//
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// orig_value = mem;
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// if (mem == old_value) {
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// mem = new_value;
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// }
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// return orig_value;
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//
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////////////////////////////////////////////////////////////////////
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INLINE PN_int32 AtomicAdjustI386Impl::
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compare_and_exchange(TVOLATILE PN_int32 &mem, PN_int32 old_value,
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PN_int32 new_value) {
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PN_int32 prev;
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#ifdef _M_IX86
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// Windows case
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TVOLATILE PN_int32 *mem_ptr = &mem;
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__asm {
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mov edx, mem_ptr;
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mov ecx, new_value;
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mov eax, old_value;
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lock cmpxchg dword ptr [edx], ecx;
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mov prev, eax;
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}
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#elif !defined(__EDG__)
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// GCC case
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__asm__ __volatile__("lock; cmpxchgl %1,%2"
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: "=a"(prev)
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: "r"(new_value), "m"(mem), "0"(old_value)
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: "memory");
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#endif // __EDG__
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return prev;
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}
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////////////////////////////////////////////////////////////////////
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// Function: AtomicAdjustI386Impl::compare_and_exchange_ptr
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// Access: Public, Static
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// Description: Atomic compare and exchange.
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//
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// As above, but works on pointers instead of integers.
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////////////////////////////////////////////////////////////////////
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INLINE void *AtomicAdjustI386Impl::
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compare_and_exchange_ptr(void * TVOLATILE &mem, void *old_value,
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void *new_value) {
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void *prev;
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#ifdef _M_IX86
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// Windows case
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void * TVOLATILE *mem_ptr = &mem;
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__asm {
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mov edx, mem_ptr;
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mov ecx, new_value;
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mov eax, old_value;
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lock cmpxchg dword ptr [edx], ecx;
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mov prev, eax;
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}
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#elif !defined(__EDG__)
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// GCC case
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__asm__ __volatile__("lock; cmpxchgl %1,%2"
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: "=a"(prev)
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: "r"(new_value), "m"(mem), "0"(old_value)
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: "memory");
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#endif // __EDG__
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return prev;
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}
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