upload android base code part4

android/hardware/libhardware_legacy/power.c

@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+#include <hardware_legacy/power.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <pthread.h>
+
+#define LOG_TAG "power"
+#include <log/log.h>
+
+enum {
+    ACQUIRE_PARTIAL_WAKE_LOCK = 0,
+    RELEASE_WAKE_LOCK,
+    OUR_FD_COUNT
+};
+
+const char * const OLD_PATHS[] = {
+    "/sys/android_power/acquire_partial_wake_lock",
+    "/sys/android_power/release_wake_lock",
+};
+
+const char * const NEW_PATHS[] = {
+    "/sys/power/wake_lock",
+    "/sys/power/wake_unlock",
+};
+
+//XXX static pthread_once_t g_initialized = THREAD_ONCE_INIT;
+static int g_initialized = 0;
+static int g_fds[OUR_FD_COUNT];
+static int g_error = -1;
+
+static int
+open_file_descriptors(const char * const paths[])
+{
+    int i;
+    for (i=0; i<OUR_FD_COUNT; i++) {
+        int fd = open(paths[i], O_RDWR | O_CLOEXEC);
+        if (fd < 0) {
+            g_error = -errno;
+            fprintf(stderr, "fatal error opening \"%s\": %s\n", paths[i],
+                strerror(errno));
+            return -1;
+        }
+        g_fds[i] = fd;
+    }
+
+    g_error = 0;
+    return 0;
+}
+
+static inline void
+initialize_fds(void)
+{
+    // XXX: should be this:
+    //pthread_once(&g_initialized, open_file_descriptors);
+    // XXX: not this:
+    if (g_initialized == 0) {
+        if(open_file_descriptors(NEW_PATHS) < 0)
+            open_file_descriptors(OLD_PATHS);
+        g_initialized = 1;
+    }
+}
+
+int
+acquire_wake_lock(int lock, const char* id)
+{
+    initialize_fds();
+
+//    ALOGI("acquire_wake_lock lock=%d id='%s'\n", lock, id);
+
+    if (g_error) return g_error;
+
+    int fd;
+    size_t len;
+    ssize_t ret;
+
+    if (lock != PARTIAL_WAKE_LOCK) {
+        return -EINVAL;
+    }
+
+    fd = g_fds[ACQUIRE_PARTIAL_WAKE_LOCK];
+
+    ret = write(fd, id, strlen(id));
+    if (ret < 0) {
+        return -errno;
+    }
+
+    return ret;
+}
+
+int
+release_wake_lock(const char* id)
+{
+    initialize_fds();
+
+//    ALOGI("release_wake_lock id='%s'\n", id);
+
+    if (g_error) return g_error;
+
+    ssize_t len = write(g_fds[RELEASE_WAKE_LOCK], id, strlen(id));
+    if (len < 0) {
+        return -errno;
+    }
+    return len;
+}