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Commit 9cb2e2eb authored by Josh Gao's avatar Josh Gao
Browse files

libprocinfo: add support for parsing process state. 

Bug: http://b/63008395
Test: libprocinfo_test32
Change-Id: I20a337bb5075bcdb325d2b48e174b0b5ef896261
parent 3e8d9232

libprocinfo/include/procinfo/process.h

+10 −0
Original line number Diff line number Diff line
@@ -35,8 +35,18 @@ namespace procinfo { 


#if defined(__linux__)



enum ProcessState {

  kProcessStateUnknown,

  kProcessStateRunning,

  kProcessStateSleeping,

  kProcessStateUninterruptibleWait,

  kProcessStateStopped,

  kProcessStateZombie,

};



struct ProcessInfo {

  std::string name;

  ProcessState state;

  pid_t tid;

  pid_t pid;

  pid_t ppid;

libprocinfo/process.cpp

+22 −1
Original line number Diff line number Diff line
@@ -44,6 +44,24 @@ bool GetProcessInfo(pid_t tid, ProcessInfo* process_info) { 
  return GetProcessInfoFromProcPidFd(dirfd.get(), process_info);

}



static ProcessState parse_state(const char* state) {

  switch (*state) {

    case 'R':

      return kProcessStateRunning;

    case 'S':

      return kProcessStateSleeping;

    case 'D':

      return kProcessStateUninterruptibleWait;

    case 'T':

      return kProcessStateStopped;

    case 'Z':

      return kProcessStateZombie;

    default:

      LOG(ERROR) << "unknown process state: " << *state;

      return kProcessStateUnknown;

  }

}



bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info) {

  int status_fd = openat(fd, "status", O_RDONLY | O_CLOEXEC);
@@ -60,7 +78,7 @@ bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info) { 
  }



  int field_bitmap = 0;

  static constexpr int finished_bitmap = 127;

  static constexpr int finished_bitmap = 255;

  char* line = nullptr;

  size_t len = 0;
@@ -98,6 +116,9 @@ bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info) { 
    } else if (header == "Gid:") {

      process_info->gid = atoi(tab + 1);

      field_bitmap |= 64;

    } else if (header == "State:") {

      process_info->state = parse_state(tab + 1);

      field_bitmap |= 128;

    }

  }

libprocinfo/process_test.cpp

+34 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <sys/types.h>

#include <unistd.h>



#include <chrono>

#include <set>

#include <thread>

#include <vector>
@@ -29,6 +30,8 @@ 


#include <android-base/stringprintf.h>



using namespace std::chrono_literals;



#if !defined(__BIONIC__)

#include <syscall.h>

static pid_t gettid() {
@@ -82,3 +85,34 @@ TEST(process_info, process_tids_smoke) { 
    }

  }).join();

}



TEST(process_info, process_state) {

  int pipefd[2];

  ASSERT_EQ(0, pipe2(pipefd, O_CLOEXEC));

  pid_t forkpid = fork();



  ASSERT_NE(-1, forkpid);

  if (forkpid == 0) {

    close(pipefd[1]);

    char buf;

    TEMP_FAILURE_RETRY(read(pipefd[0], &buf, 1));

    _exit(0);

  }



  // Give the child some time to get to the read.

  std::this_thread::sleep_for(100ms);



  android::procinfo::ProcessInfo procinfo;

  ASSERT_TRUE(android::procinfo::GetProcessInfo(forkpid, &procinfo));

  ASSERT_EQ(android::procinfo::kProcessStateSleeping, procinfo.state);



  ASSERT_EQ(0, kill(forkpid, SIGKILL));



  // Give the kernel some time to kill the child.

  std::this_thread::sleep_for(100ms);



  ASSERT_TRUE(android::procinfo::GetProcessInfo(forkpid, &procinfo));

  ASSERT_EQ(android::procinfo::kProcessStateZombie, procinfo.state);



  ASSERT_EQ(forkpid, waitpid(forkpid, nullptr, 0));

}