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authorGravatar Yash Tibrewal <yashkt@google.com>2017-10-05 10:13:58 -0700
committerGravatar GitHub <noreply@github.com>2017-10-05 10:13:58 -0700
commitc277fc0818eb2e7408db6758c9690bb4eb2c6ff7 (patch)
tree39d7303f599411ab00e780a26477d34be72b6ace /src/core/lib/support/cpu_posix.cc
parentd6b7a28e36a84e67a64a7ddd6d4ebba0f783f912 (diff)
parent70d3424005f30ff651768b2a86a1fa6f1158eb67 (diff)
Merge pull request #12692 from yashykt/externC
Converting src/core files from C to CC
Diffstat (limited to 'src/core/lib/support/cpu_posix.cc')
-rw-r--r--src/core/lib/support/cpu_posix.cc58
1 files changed, 58 insertions, 0 deletions
diff --git a/src/core/lib/support/cpu_posix.cc b/src/core/lib/support/cpu_posix.cc
new file mode 100644
index 0000000000..503a96b4c8
--- /dev/null
+++ b/src/core/lib/support/cpu_posix.cc
@@ -0,0 +1,58 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * 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.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_CPU_POSIX
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <grpc/support/cpu.h>
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/useful.h>
+
+static __thread char magic_thread_local;
+
+static long ncpus = 0;
+
+static void init_ncpus() {
+ ncpus = sysconf(_SC_NPROCESSORS_ONLN);
+ if (ncpus < 1 || ncpus > INT32_MAX) {
+ gpr_log(GPR_ERROR, "Cannot determine number of CPUs: assuming 1");
+ ncpus = 1;
+ }
+}
+
+unsigned gpr_cpu_num_cores(void) {
+ static gpr_once once = GPR_ONCE_INIT;
+ gpr_once_init(&once, init_ncpus);
+ return (unsigned)ncpus;
+}
+
+unsigned gpr_cpu_current_cpu(void) {
+ /* NOTE: there's no way I know to return the actual cpu index portably...
+ most code that's using this is using it to shard across work queues though,
+ so here we use thread identity instead to achieve a similar though not
+ identical effect */
+ return (unsigned)GPR_HASH_POINTER(&magic_thread_local, gpr_cpu_num_cores());
+}
+
+#endif /* GPR_CPU_POSIX */