add a preliminary implementation of futex in macos

example/echo_c++/CMakeLists.txt

@@ -66,6 +66,16 @@ if ((NOT LEVELDB_INCLUDE_PATH) OR (NOT LEVELDB_LIB))
 endif()
 include_directories(${LEVELDB_INCLUDE_PATH})
 
+find_library(SSL_LIB NAMES ssl)
+if (NOT SSL_LIB)
+    message(FATAL_ERROR "Fail to find ssl")
+endif()
+
+find_library(CRYPTO_LIB NAMES crypto)
+if (NOT CRYPTO_LIB)
+    message(FATAL_ERROR "Fail to find crypto")
+endif()
+
 add_executable(echo_client client.cpp ${PROTO_SRC} ${PROTO_HEADER})
 add_executable(echo_server server.cpp ${PROTO_SRC} ${PROTO_HEADER})
 
@@ -74,10 +84,24 @@ set(DYNAMIC_LIB
     ${GFLAGS_LIBRARY}
     ${PROTOBUF_LIBRARIES}
     ${LEVELDB_LIB}
-    ssl
-    crypto
+    ${SSL_LIB}
+    ${CRYPTO_LIB}
     dl
     )
 
+if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+    set(DYNAMIC_LIB ${DYNAMIC_LIB}
+        pthread
+        "-framework CoreFoundation"
+        "-framework CoreGraphics"
+        "-framework CoreData"
+        "-framework CoreText"
+        "-framework Security"
+        "-framework Foundation"
+        "-Wl,-U,_MallocExtension_ReleaseFreeMemory"
+        "-Wl,-U,_ProfilerStart"
+        "-Wl,-U,_ProfilerStop")
+endif()
+
 target_link_libraries(echo_client ${BRPC_LIB} ${DYNAMIC_LIB})
 target_link_libraries(echo_server ${BRPC_LIB} ${DYNAMIC_LIB})

src/bthread/sys_futex.cpp

+// bthread - A M:N threading library to make applications more concurrent.
+// Copyright (c) 2012 Baidu, Inc.
+//
+// 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.
+
+// Author: Zhu,Jiashun (zhujiahun@baidu.com)
+// Date: Wed Mar 14 17:44:58 CST 2018
+
+#include "bthread/sys_futex.h"
+#include "butil/scoped_lock.h"
+#include <map>
+#include <pthread.h>
+
+#if defined(OS_MACOSX)
+
+namespace bthread {
+
+struct SimuFutex {
+    pthread_mutex_t lock;
+    pthread_cond_t cond;
+
+    SimuFutex() {
+        pthread_mutex_init(&lock, NULL);
+        pthread_cond_init(&cond, NULL);
+    }
+    ~SimuFutex() {
+        pthread_mutex_destroy(&lock);
+        pthread_cond_destroy(&cond);
+    }
+};
+
+// TODO: use a more efficient way. Current impl doesn't delete SimuFutex at all.
+static std::map<void*, SimuFutex> s_futex_map;
+static pthread_mutex_t s_futex_map_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+int futex_wait_private(void* addr1, int expected, const timespec* timeout) {
+    std::unique_lock<pthread_mutex_t> mu(s_futex_map_mutex);
+    SimuFutex& simu_futex = s_futex_map[addr1];
+    mu.unlock();
+    int rc = pthread_mutex_lock(&simu_futex.lock);
+    if (rc < 0) {
+        return rc;
+    }
+    if (static_cast<butil::atomic<int>*>(addr1)->load() == expected) {
+        pthread_cond_wait(&simu_futex.cond, &simu_futex.lock);
+    }
+    rc = pthread_mutex_unlock(&simu_futex.lock);
+    if (rc < 0) {
+        return rc;
+    }
+    return 0;
+}
+
+int futex_wake_private(void* addr1, int nwake) {
+    std::unique_lock<pthread_mutex_t> mu(s_futex_map_mutex);
+    SimuFutex& simu_futex = s_futex_map[addr1];
+    mu.unlock();
+    int rc = pthread_mutex_lock(&simu_futex.lock);
+    if (rc < 0) {
+        return rc;
+    }
+    for (int i = 0; i < nwake; ++i) {
+        rc = pthread_cond_signal(&simu_futex.cond);
+        if (rc < 0) {
+            return rc;
+        }
+    }
+    rc = pthread_mutex_unlock(&simu_futex.lock);
+    if (rc < 0) {
+        return rc;
+    }
+    return 0;
+}
+
+int futex_requeue_private(void* addr1, int nwake, void* addr2) {
+    // TODO
+    return -1;
+}
+
+} // namespace bthread
+
+#endif

src/bthread/sys_futex.h

@@ -53,18 +53,13 @@ inline int futex_requeue_private(void* addr1, int nwake, void* addr2) {
 #elif defined(OS_MACOSX)
 
 namespace bthread {
-inline int futex_wait_private(
-    void* addr1, int expected, const timespec* timeout) {
-    return -1;
-}
 
-inline int futex_wake_private(void* addr1, int nwake) {
-    return -1;
-}
+int futex_wait_private(void* addr1, int expected, const timespec* timeout);
+
+int futex_wake_private(void* addr1, int nwake);
+
+int futex_requeue_private(void* addr1, int nwake, void* addr2);
 
-inline int futex_requeue_private(void* addr1, int nwake, void* addr2) {
-    return -1;
-}
 }  // namespace bthread
 
 #else