libcutils: Move sched_policy functions into libprocessgroup

Move functions operating on cgroups from sched_policy.h in libcutils
into sched_policy_ctrl.h under libprocessgroup. This consolidates
cgroup-related functionality inside libprocessgroup.

Bug: 111307099
Test: builds, boots

Change-Id: Iba75f33281162b889989214d0325a5973d53ed2d
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

1 files changed, 0 insertions, 476 deletions

diff --git a/libcutils/sched_policy.cpp b/libcutils/sched_policy.cpp
deleted file mode 100644
index 3fa548f78..000000000
--- a/libcutils/sched_policy.cpp
+++ /dev/null
@@ -1,476 +0,0 @@
-/*
-** Copyright 2007, 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 <cutils/sched_policy.h>
-
-#define LOG_TAG "SchedPolicy"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <android-base/macros.h>
-#include <log/log.h>
-
-/* Re-map SP_DEFAULT to the system default policy, and leave other values unchanged.
- * Call this any place a SchedPolicy is used as an input parameter.
- * Returns the possibly re-mapped policy.
- */
-static inline SchedPolicy _policy(SchedPolicy p)
-{
-   return p == SP_DEFAULT ? SP_SYSTEM_DEFAULT : p;
-}
-
-#if defined(__ANDROID__)
-
-#include <pthread.h>
-#include <sched.h>
-#include <sys/prctl.h>
-
-#define POLICY_DEBUG 0
-
-// timer slack value in nS enforced when the thread moves to background
-#define TIMER_SLACK_BG 40000000
-#define TIMER_SLACK_FG 50000
-
-static pthread_once_t the_once = PTHREAD_ONCE_INIT;
-
-static int __sys_supports_timerslack = -1;
-
-// File descriptors open to /dev/cpuset/../tasks, setup by initialize, or -1 on error
-static int system_bg_cpuset_fd = -1;
-static int bg_cpuset_fd = -1;
-static int fg_cpuset_fd = -1;
-static int ta_cpuset_fd = -1; // special cpuset for top app
-static int rs_cpuset_fd = -1;  // special cpuset for screen off restrictions
-
-// File descriptors open to /dev/stune/../tasks, setup by initialize, or -1 on error
-static int bg_schedboost_fd = -1;
-static int fg_schedboost_fd = -1;
-static int ta_schedboost_fd = -1;
-static int rt_schedboost_fd = -1;
-
-/* Add tid to the scheduling group defined by the policy */
-static int add_tid_to_cgroup(int tid, int fd)
-{
-    if (fd < 0) {
-        SLOGE("add_tid_to_cgroup failed; fd=%d\n", fd);
-        errno = EINVAL;
-        return -1;
-    }
-
-    // specialized itoa -- works for tid > 0
-    char text[22];
-    char *end = text + sizeof(text) - 1;
-    char *ptr = end;
-    *ptr = '\0';
-    while (tid > 0) {
-        *--ptr = '0' + (tid % 10);
-        tid = tid / 10;
-    }
-
-    if (write(fd, ptr, end - ptr) < 0) {
-        /*
-         * If the thread is in the process of exiting,
-         * don't flag an error
-         */
-        if (errno == ESRCH)
-                return 0;
-        SLOGW("add_tid_to_cgroup failed to write '%s' (%s); fd=%d\n",
-              ptr, strerror(errno), fd);
-        errno = EINVAL;
-        return -1;
-    }
-
-    return 0;
-}
-
-/*
-    If CONFIG_CPUSETS for Linux kernel is set, "tasks" can be found under
-    /dev/cpuset mounted in init.rc; otherwise, that file does not exist
-    even though the directory, /dev/cpuset, is still created (by init.rc).
-
-    A couple of other candidates (under cpuset mount directory):
-        notify_on_release
-        release_agent
-
-    Yet another way to decide if cpuset is enabled is to parse
-    /proc/self/status and search for lines begin with "Mems_allowed".
-
-    If CONFIG_PROC_PID_CPUSET is set, the existence "/proc/self/cpuset" can
-    be used to decide if CONFIG_CPUSETS is set, so we don't have a dependency
-    on where init.rc mounts cpuset. That's why we'd better require this
-    configuration be set if CONFIG_CPUSETS is set.
-
-    In older releases, this was controlled by build-time configuration.
- */
-bool cpusets_enabled() {
-    static bool enabled = (access("/dev/cpuset/tasks", F_OK) == 0);
-
-    return enabled;
-}
-
-/*
-    Similar to CONFIG_CPUSETS above, but with a different configuration
-    CONFIG_CGROUP_SCHEDTUNE that's in Android common Linux kernel and Linaro
-    Stable Kernel (LSK), but not in mainline Linux as of v4.9.
-
-    In older releases, this was controlled by build-time configuration.
- */
-bool schedboost_enabled() {
-    static bool enabled = (access("/dev/stune/tasks", F_OK) == 0);
-
-    return enabled;
-}
-
-static void __initialize() {
-    const char* filename;
-
-    if (cpusets_enabled()) {
-        if (!access("/dev/cpuset/tasks", W_OK)) {
-
-            filename = "/dev/cpuset/foreground/tasks";
-            fg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-            filename = "/dev/cpuset/background/tasks";
-            bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-            filename = "/dev/cpuset/system-background/tasks";
-            system_bg_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-            filename = "/dev/cpuset/top-app/tasks";
-            ta_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-            filename = "/dev/cpuset/restricted/tasks";
-            rs_cpuset_fd = open(filename, O_WRONLY | O_CLOEXEC);
-
-            if (schedboost_enabled()) {
-                filename = "/dev/stune/top-app/tasks";
-                ta_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-                filename = "/dev/stune/foreground/tasks";
-                fg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-                filename = "/dev/stune/background/tasks";
-                bg_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-                filename = "/dev/stune/rt/tasks";
-                rt_schedboost_fd = open(filename, O_WRONLY | O_CLOEXEC);
-            }
-        }
-    }
-
-    char buf[64];
-    snprintf(buf, sizeof(buf), "/proc/%d/timerslack_ns", getpid());
-    __sys_supports_timerslack = !access(buf, W_OK);
-}
-
-/*
- * Returns the path under the requested cgroup subsystem (if it exists)
- *
- * The data from /proc/<pid>/cgroup looks (something) like:
- *  2:cpu:/bg_non_interactive
- *  1:cpuacct:/
- *
- * We return the part after the "/", which will be an empty string for
- * the default cgroup.  If the string is longer than "bufLen", the string
- * will be truncated.
- */
-static int getCGroupSubsys(int tid, const char* subsys, char* buf, size_t bufLen)
-{
-#if defined(__ANDROID__)
-    char pathBuf[32];
-    char lineBuf[256];
-    FILE *fp;
-
-    snprintf(pathBuf, sizeof(pathBuf), "/proc/%d/cgroup", tid);
-    if (!(fp = fopen(pathBuf, "re"))) {
-        return -1;
-    }
-
-    while(fgets(lineBuf, sizeof(lineBuf) -1, fp)) {
-        char *next = lineBuf;
-        char *found_subsys;
-        char *grp;
-        size_t len;
-
-        /* Junk the first field */
-        if (!strsep(&next, ":")) {
-            goto out_bad_data;
-        }
-
-        if (!(found_subsys = strsep(&next, ":"))) {
-            goto out_bad_data;
-        }
-
-        if (strcmp(found_subsys, subsys)) {
-            /* Not the subsys we're looking for */
-            continue;
-        }
-
-        if (!(grp = strsep(&next, ":"))) {
-            goto out_bad_data;
-        }
-        grp++; /* Drop the leading '/' */
-        len = strlen(grp);
-        grp[len-1] = '\0'; /* Drop the trailing '\n' */
-
-        if (bufLen <= len) {
-            len = bufLen - 1;
-        }
-        strncpy(buf, grp, len);
-        buf[len] = '\0';
-        fclose(fp);
-        return 0;
-    }
-
-    SLOGE("Failed to find subsys %s", subsys);
-    fclose(fp);
-    return -1;
- out_bad_data:
-    SLOGE("Bad cgroup data {%s}", lineBuf);
-    fclose(fp);
-    return -1;
-#else
-    errno = ENOSYS;
-    return -1;
-#endif
-}
-
-int get_sched_policy(int tid, SchedPolicy *policy)
-{
-    if (tid == 0) {
-        tid = gettid();
-    }
-    pthread_once(&the_once, __initialize);
-
-    char grpBuf[32];
-
-    grpBuf[0] = '\0';
-    if (schedboost_enabled()) {
-        if (getCGroupSubsys(tid, "schedtune", grpBuf, sizeof(grpBuf)) < 0) return -1;
-    }
-    if ((grpBuf[0] == '\0') && cpusets_enabled()) {
-        if (getCGroupSubsys(tid, "cpuset", grpBuf, sizeof(grpBuf)) < 0) return -1;
-    }
-    if (grpBuf[0] == '\0') {
-        *policy = SP_FOREGROUND;
-    } else if (!strcmp(grpBuf, "foreground")) {
-        *policy = SP_FOREGROUND;
-    } else if (!strcmp(grpBuf, "system-background")) {
-        *policy = SP_SYSTEM;
-    } else if (!strcmp(grpBuf, "background")) {
-        *policy = SP_BACKGROUND;
-    } else if (!strcmp(grpBuf, "top-app")) {
-        *policy = SP_TOP_APP;
-    } else {
-        errno = ERANGE;
-        return -1;
-    }
-    return 0;
-}
-
-int set_cpuset_policy(int tid, SchedPolicy policy)
-{
-    // in the absence of cpusets, use the old sched policy
-    if (!cpusets_enabled()) {
-        return set_sched_policy(tid, policy);
-    }
-
-    if (tid == 0) {
-        tid = gettid();
-    }
-    policy = _policy(policy);
-    pthread_once(&the_once, __initialize);
-
-    int fd = -1;
-    int boost_fd = -1;
-    switch (policy) {
-    case SP_BACKGROUND:
-        fd = bg_cpuset_fd;
-        boost_fd = bg_schedboost_fd;
-        break;
-    case SP_FOREGROUND:
-    case SP_AUDIO_APP:
-    case SP_AUDIO_SYS:
-        fd = fg_cpuset_fd;
-        boost_fd = fg_schedboost_fd;
-        break;
-    case SP_TOP_APP :
-        fd = ta_cpuset_fd;
-        boost_fd = ta_schedboost_fd;
-        break;
-    case SP_SYSTEM:
-        fd = system_bg_cpuset_fd;
-        break;
-    case SP_RESTRICTED:
-        fd = rs_cpuset_fd;
-        break;
-    default:
-        boost_fd = fd = -1;
-        break;
-    }
-
-    if (add_tid_to_cgroup(tid, fd) != 0) {
-        if (errno != ESRCH && errno != ENOENT)
-            return -errno;
-    }
-
-    if (schedboost_enabled()) {
-        if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
-            if (errno != ESRCH && errno != ENOENT)
-                return -errno;
-        }
-    }
-
-    return 0;
-}
-
-static void set_timerslack_ns(int tid, unsigned long slack) {
-    // v4.6+ kernels support the /proc/<tid>/timerslack_ns interface.
-    // TODO: once we've backported this, log if the open(2) fails.
-    if (__sys_supports_timerslack) {
-        char buf[64];
-        snprintf(buf, sizeof(buf), "/proc/%d/timerslack_ns", tid);
-        int fd = open(buf, O_WRONLY | O_CLOEXEC);
-        if (fd != -1) {
-            int len = snprintf(buf, sizeof(buf), "%lu", slack);
-            if (write(fd, buf, len) != len) {
-                SLOGE("set_timerslack_ns write failed: %s\n", strerror(errno));
-            }
-            close(fd);
-            return;
-        }
-    }
-
-    // TODO: Remove when /proc/<tid>/timerslack_ns interface is backported.
-    if ((tid == 0) || (tid == gettid())) {
-        if (prctl(PR_SET_TIMERSLACK, slack) == -1) {
-            SLOGE("set_timerslack_ns prctl failed: %s\n", strerror(errno));
-        }
-    }
-}
-
-int set_sched_policy(int tid, SchedPolicy policy)
-{
-    if (tid == 0) {
-        tid = gettid();
-    }
-    policy = _policy(policy);
-    pthread_once(&the_once, __initialize);
-
-#if POLICY_DEBUG
-    char statfile[64];
-    char statline[1024];
-    char thread_name[255];
-
-    snprintf(statfile, sizeof(statfile), "/proc/%d/stat", tid);
-    memset(thread_name, 0, sizeof(thread_name));
-
-    int fd = open(statfile, O_RDONLY | O_CLOEXEC);
-    if (fd >= 0) {
-        int rc = read(fd, statline, 1023);
-        close(fd);
-        statline[rc] = 0;
-        char *p = statline;
-        char *q;
-
-        for (p = statline; *p != '('; p++);
-        p++;
-        for (q = p; *q != ')'; q++);
-
-        strncpy(thread_name, p, (q-p));
-    }
-    switch (policy) {
-    case SP_BACKGROUND:
-        SLOGD("vvv tid %d (%s)", tid, thread_name);
-        break;
-    case SP_FOREGROUND:
-    case SP_AUDIO_APP:
-    case SP_AUDIO_SYS:
-    case SP_TOP_APP:
-        SLOGD("^^^ tid %d (%s)", tid, thread_name);
-        break;
-    case SP_SYSTEM:
-        SLOGD("/// tid %d (%s)", tid, thread_name);
-        break;
-    case SP_RT_APP:
-	SLOGD("RT  tid %d (%s)", tid, thread_name);
-	break;
-    default:
-        SLOGD("??? tid %d (%s)", tid, thread_name);
-        break;
-    }
-#endif
-
-    if (schedboost_enabled()) {
-        int boost_fd = -1;
-        switch (policy) {
-        case SP_BACKGROUND:
-            boost_fd = bg_schedboost_fd;
-            break;
-        case SP_FOREGROUND:
-        case SP_AUDIO_APP:
-        case SP_AUDIO_SYS:
-            boost_fd = fg_schedboost_fd;
-            break;
-        case SP_TOP_APP:
-            boost_fd = ta_schedboost_fd;
-            break;
-        case SP_RT_APP:
-	    boost_fd = rt_schedboost_fd;
-	    break;
-        default:
-            boost_fd = -1;
-            break;
-        }
-
-        if (boost_fd > 0 && add_tid_to_cgroup(tid, boost_fd) != 0) {
-            if (errno != ESRCH && errno != ENOENT)
-                return -errno;
-        }
-
-    }
-
-    set_timerslack_ns(tid, policy == SP_BACKGROUND ? TIMER_SLACK_BG : TIMER_SLACK_FG);
-
-    return 0;
-}
-
-#else
-
-/* Stubs for non-Android targets. */
-
-int set_sched_policy(int /*tid*/, SchedPolicy /*policy*/) {
-    return 0;
-}
-
-int get_sched_policy(int /*tid*/, SchedPolicy* policy) {
-    *policy = SP_SYSTEM_DEFAULT;
-    return 0;
-}
-
-#endif
-
-const char* get_sched_policy_name(SchedPolicy policy) {
-    policy = _policy(policy);
-    static const char* const kSchedPolicyNames[] = {
-            [SP_BACKGROUND] = "bg", [SP_FOREGROUND] = "fg", [SP_SYSTEM] = "  ",
-            [SP_AUDIO_APP] = "aa",  [SP_AUDIO_SYS] = "as",  [SP_TOP_APP] = "ta",
-            [SP_RT_APP] = "rt",     [SP_RESTRICTED] = "rs",
-    };
-    static_assert(arraysize(kSchedPolicyNames) == SP_CNT, "missing name");
-    if (policy < SP_BACKGROUND || policy >= SP_CNT) {
-        return "error";
-    }
-    return kSchedPolicyNames[policy];
-}