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| -rw-r--r-- | src/rocksdb/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h b/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h new file mode 100644 index 000000000..46111e7f0 --- /dev/null +++ b/src/rocksdb/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h @@ -0,0 +1,193 @@ +/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */ +// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4: +#ident "$Id$" +/*====== +This file is part of PerconaFT. + + +Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved. + + PerconaFT is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License, version 2, + as published by the Free Software Foundation. + + PerconaFT is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. + +---------------------------------------- + + PerconaFT is free software: you can redistribute it and/or modify + it under the terms of the GNU Affero General Public License, version 3, + as published by the Free Software Foundation. + + PerconaFT is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with PerconaFT. If not, see <http://www.gnu.org/licenses/>. + +---------------------------------------- + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +======= */ + +#ident \ + "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved." + +#pragma once + +// PORT2: #include "toku_config.h" + +#include <stdint.h> +#include <sys/time.h> +#include <time.h> +#if defined(__powerpc__) +#include <sys/platform/ppc.h> +#endif + +#if 0 +static inline float toku_tdiff (struct timeval *a, struct timeval *b) { + return (float)((a->tv_sec - b->tv_sec) + 1e-6 * (a->tv_usec - b->tv_usec)); +} +// PORT2: temporary: +#define HAVE_CLOCK_REALTIME +#if !defined(HAVE_CLOCK_REALTIME) +// OS X does not have clock_gettime, we fake clockid_t for the interface, and we'll implement it with clock_get_time. +typedef int clockid_t; +// just something bogus, it doesn't matter, we just want to make sure we're +// only supporting this mode because we're not sure we can support other modes +// without a real clock_gettime() +#define CLOCK_REALTIME 0x01867234 +#endif +int toku_clock_gettime(clockid_t clk_id, struct timespec *ts) __attribute__((__visibility__("default"))); +#endif + +// *************** Performance timers ************************ +// What do you really want from a performance timer: +// (1) Can determine actual time of day from the performance time. +// (2) Time goes forward, never backward. +// (3) Same time on different processors (or even different machines). +// (4) Time goes forward at a constant rate (doesn't get faster and slower) +// (5) Portable. +// (6) Getting the time is cheap. +// Unfortuately it seems tough to get Properties 1-5. So we go for Property 6,, +// but we abstract it. We offer a type tokutime_t which can hold the time. This +// type can be subtracted to get a time difference. We can get the present time +// cheaply. We can convert this type to seconds (but that can be expensive). The +// implementation is to use RDTSC (hence we lose property 3: not portable). +// Recent machines have constant_tsc in which case we get property (4). +// Recent OSs on recent machines (that have RDTSCP) fix the per-processor clock +// skew, so we get property (3). We get property 2 with RDTSC (as long as +// there's not any skew). We don't even try to get propety 1, since we don't +// need it. The decision here is that these times are really accurate only on +// modern machines with modern OSs. +typedef uint64_t tokutime_t; // Time type used in by tokutek timers. + +#if 0 +// The value of tokutime_t is not specified here. +// It might be microseconds since 1/1/1970 (if gettimeofday() is +// used), or clock cycles since boot (if rdtsc is used). Or something +// else. +// Two tokutime_t values can be subtracted to get a time difference. +// Use tokutime_to_seconds to that convert difference to seconds. +// We want get_tokutime() to be fast, but don't care so much about tokutime_to_seconds(); +// +// For accurate time calculations do the subtraction in the right order: +// Right: tokutime_to_seconds(t1-t2); +// Wrong tokutime_to_seconds(t1)-toku_time_to_seconds(t2); +// Doing it the wrong way is likely to result in loss of precision. +// A double can hold numbers up to about 53 bits. RDTSC which uses about 33 bits every second, so that leaves +// 2^20 seconds from booting (about 2 weeks) before the RDTSC value cannot be represented accurately as a double. +// +double tokutime_to_seconds(tokutime_t) __attribute__((__visibility__("default"))); // Convert tokutime to seconds. + +#endif + +// Get the value of tokutime for right now. We want this to be fast, so we +// expose the implementation as RDTSC. +static inline tokutime_t toku_time_now(void) { +#if defined(__x86_64__) || defined(__i386__) + uint32_t lo, hi; + __asm__ __volatile__("rdtsc" : "=a"(lo), "=d"(hi)); + return (uint64_t)hi << 32 | lo; +#elif defined(__aarch64__) + uint64_t result; + __asm __volatile__("mrs %[rt], cntvct_el0" : [rt] "=r"(result)); + return result; +#elif defined(__powerpc__) + return __ppc_get_timebase(); +#elif defined(__s390x__) + uint64_t result; + asm volatile("stckf %0" : "=Q"(result) : : "cc"); + return result; +#elif defined(__riscv) && __riscv_xlen == 32 + uint32_t cycles_lo, cycles_hi0, cycles_hi1; + // Implemented in assembly because Clang insisted on branching. + asm volatile( + "rdcycleh %0\n" + "rdcycle %1\n" + "rdcycleh %2\n" + "sub %0, %0, %2\n" + "seqz %0, %0\n" + "sub %0, zero, %0\n" + "and %1, %1, %0\n" + : "=r"(cycles_hi0), "=r"(cycles_lo), "=r"(cycles_hi1)); + return (static_cast<uint64_t>(cycles_hi1) << 32) | cycles_lo; +#elif defined(__riscv) && __riscv_xlen == 64 + uint64_t cycles; + asm volatile("rdcycle %0" : "=r"(cycles)); + return cycles; +#else +#error No timer implementation for this platform +#endif +} + +static inline uint64_t toku_current_time_microsec(void) { + struct timeval t; + gettimeofday(&t, NULL); + return t.tv_sec * (1UL * 1000 * 1000) + t.tv_usec; +} + +#if 0 +// sleep microseconds +static inline void toku_sleep_microsec(uint64_t ms) { + struct timeval t; + + t.tv_sec = ms / 1000000; + t.tv_usec = ms % 1000000; + + select(0, NULL, NULL, NULL, &t); +} +#endif + +/* + PORT: Usage of this file: + + uint64_t toku_current_time_microsec() // uses gettimeoday + is used to track how much time various operations took (for example, lock + escalation). (TODO: it is not clear why these operations are tracked with + microsecond precision while others use nanoseconds) + + tokutime_t toku_time_now() // uses rdtsc + seems to be used for a very similar purpose. This has greater precision + + RocksDB environment provides Env::Default()->NowMicros() and NowNanos() which + should be adequate substitutes. +*/ |