diff options
Diffstat (limited to 'include/grpc/support/atm.h')
-rw-r--r-- | include/grpc/support/atm.h | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/include/grpc/support/atm.h b/include/grpc/support/atm.h new file mode 100644 index 0000000000..d9fd383209 --- /dev/null +++ b/include/grpc/support/atm.h @@ -0,0 +1,92 @@ +/* + * + * Copyright 2014, Google Inc. + * 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. + * + */ + +#ifndef __GRPC_SUPPORT_ATM_H__ +#define __GRPC_SUPPORT_ATM_H__ + +/* This interface provides atomic operations and barriers. + It is internal to gpr support code and should not be used outside it. + + If an operation with acquire semantics precedes another memory access by the + same thread, the operation will precede that other access as seen by other + threads. + + If an operation with release semantics follows another memory access by the + same thread, the operation will follow that other access as seen by other + threads. + + Routines with "acq" or "full" in the name have acquire semantics. Routines + with "rel" or "full" in the name have release semantics. Routines with + "no_barrier" in the name have neither acquire not release semantics. + + The routines may be implemented as macros. + + // Atomic operations acton an intergral_type gpr_atm that is guaranteed to + // be the same size as a pointer. + typedef gpr_intptr gpr_atm; + + // A memory barrier, providing both acquire and release semantics, but not + // otherwise acting no memory. + void gpr_atm_full_barrier(void); + + // Atomically return *p, with acquire semantics. + gpr_atm gpr_atm_acq_load(gpr_atm *p); + + // Atomically set *p = value, with release semantics. + void gpr_atm_rel_store(gpr_atm *p, gpr_atm value); + + // Atomically add delta to *p, and return the old value of *p, with + // the barriers specified. + gpr_atm gpr_atm_no_barrier_fetch_add(gpr_atm *p, gpr_atm delta); + gpr_atm gpr_atm_full_fetch_add(gpr_atm *p, gpr_atm delta); + + // Atomically, if *p==o, set *p=n and return non-zero otherwise return 0, + // with the barriers specified if the operation succeeds. + int gpr_atm_no_barrier_cas(gpr_atm *p, gpr_atm o, gpr_atm n); + int gpr_atm_acq_cas(gpr_atm *p, gpr_atm o, gpr_atm n); + int gpr_atm_rel_cas(gpr_atm *p, gpr_atm o, gpr_atm n); +*/ + +#include <grpc/support/port_platform.h> + +#if defined(GPR_GCC_ATOMIC) +#include <grpc/support/atm_gcc_atomic.h> +#elif defined(GPR_GCC_SYNC) +#include <grpc/support/atm_gcc_sync.h> +#elif defined(GPR_WIN32) +#include <grpc/support/atm_win32.h> +#else +#error could not determine platform for atm +#endif + +#endif /* __GRPC_SUPPORT_ATM_H__ */ |