Upintegrate the common_time service from ics-aah.
Move the common_time service developed in the ics-aah branch back into
master.
The common_time service is a small service build to synchronize an
arbitrary timeline amongst peers on a local sub-net. While running
and configured, the service will elect a master from the set of
available devices within the subnet, define a relationship between the
common_time timeline the local time timeline (provided by the local
time HAL), and then attempt to maintain synchronization between common
and local time by controlling the frequency of the local time clock
via the HAL, or by disciplining local time in the digital domain if
the local time HAL implementation does not support HW slewing.
On its own, the native common time service will do nothing until it is
configured. The CommonTimeManagementService (running out of the
system server process) is responsible for implementing policy
regarding configuration and operation of the common_time service and
will be added in a subsequent CL.
Change-Id: I71292f9b9b1797665865689c4572c9d3a0552f64
Signed-off-by: John Grossman <johngro@google.com>
diff --git a/services/common_time/common_clock.cpp b/services/common_time/common_clock.cpp
new file mode 100644
index 0000000..c9eb388
--- /dev/null
+++ b/services/common_time/common_clock.cpp
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#define __STDC_LIMIT_MACROS
+
+#define LOG_TAG "common_time"
+#include <utils/Log.h>
+
+#include <stdint.h>
+
+#include <utils/Errors.h>
+#include <utils/LinearTransform.h>
+
+#include "common_clock.h"
+
+namespace android {
+
+CommonClock::CommonClock() {
+ cur_slew_ = 0;
+ cur_trans_valid_ = false;
+
+ cur_trans_.a_zero = 0;
+ cur_trans_.b_zero = 0;
+ cur_trans_.a_to_b_numer = local_to_common_freq_numer_ = 1;
+ cur_trans_.a_to_b_denom = local_to_common_freq_denom_ = 1;
+ duration_trans_ = cur_trans_;
+}
+
+bool CommonClock::init(uint64_t local_freq) {
+ Mutex::Autolock lock(&lock_);
+
+ if (!local_freq)
+ return false;
+
+ uint64_t numer = kCommonFreq;
+ uint64_t denom = local_freq;
+
+ LinearTransform::reduce(&numer, &denom);
+ if ((numer > UINT32_MAX) || (denom > UINT32_MAX)) {
+ ALOGE("Overflow in CommonClock::init while trying to reduce %lld/%lld",
+ kCommonFreq, local_freq);
+ return false;
+ }
+
+ cur_trans_.a_to_b_numer = local_to_common_freq_numer_ =
+ static_cast<uint32_t>(numer);
+ cur_trans_.a_to_b_denom = local_to_common_freq_denom_ =
+ static_cast<uint32_t>(denom);
+ duration_trans_ = cur_trans_;
+
+ return true;
+}
+
+status_t CommonClock::localToCommon(int64_t local, int64_t *common_out) const {
+ Mutex::Autolock lock(&lock_);
+
+ if (!cur_trans_valid_)
+ return INVALID_OPERATION;
+
+ if (!cur_trans_.doForwardTransform(local, common_out))
+ return INVALID_OPERATION;
+
+ return OK;
+}
+
+status_t CommonClock::commonToLocal(int64_t common, int64_t *local_out) const {
+ Mutex::Autolock lock(&lock_);
+
+ if (!cur_trans_valid_)
+ return INVALID_OPERATION;
+
+ if (!cur_trans_.doReverseTransform(common, local_out))
+ return INVALID_OPERATION;
+
+ return OK;
+}
+
+int64_t CommonClock::localDurationToCommonDuration(int64_t localDur) const {
+ int64_t ret;
+ duration_trans_.doForwardTransform(localDur, &ret);
+ return ret;
+}
+
+void CommonClock::setBasis(int64_t local, int64_t common) {
+ Mutex::Autolock lock(&lock_);
+
+ cur_trans_.a_zero = local;
+ cur_trans_.b_zero = common;
+ cur_trans_valid_ = true;
+}
+
+void CommonClock::resetBasis() {
+ Mutex::Autolock lock(&lock_);
+
+ cur_trans_.a_zero = 0;
+ cur_trans_.b_zero = 0;
+ cur_trans_valid_ = false;
+}
+
+status_t CommonClock::setSlew(int64_t change_time, int32_t ppm) {
+ Mutex::Autolock lock(&lock_);
+
+ int64_t new_local_basis;
+ int64_t new_common_basis;
+
+ if (cur_trans_valid_) {
+ new_local_basis = change_time;
+ if (!cur_trans_.doForwardTransform(change_time, &new_common_basis)) {
+ ALOGE("Overflow when attempting to set slew rate to %d", ppm);
+ return INVALID_OPERATION;
+ }
+ } else {
+ new_local_basis = 0;
+ new_common_basis = 0;
+ }
+
+ cur_slew_ = ppm;
+ uint32_t n1 = local_to_common_freq_numer_;
+ uint32_t n2 = 1000000 + cur_slew_;
+
+ uint32_t d1 = local_to_common_freq_denom_;
+ uint32_t d2 = 1000000;
+
+ // n1/d1 has already been reduced, no need to do so here.
+ LinearTransform::reduce(&n1, &d2);
+ LinearTransform::reduce(&n2, &d1);
+ LinearTransform::reduce(&n2, &d2);
+
+ cur_trans_.a_zero = new_local_basis;
+ cur_trans_.b_zero = new_common_basis;
+ cur_trans_.a_to_b_numer = n1 * n2;
+ cur_trans_.a_to_b_denom = d1 * d2;
+
+ return OK;
+}
+
+} // namespace android