tequilaOS/platform_system_core
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libprocinfo: return error msg instead of printing it.

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So users can decide whether to print error msg or not.

Bug: none
Test: run libprocinfo_test.
Change-Id: Ie1afcb58cb97493c7ffade6841b6eb7a800a3981
This commit is contained in:
Yabin Cui 2018-07-24 10:52:25 -07:00
parent a54c293822
commit 5f036ab89b
2 changed files with 29 additions and 15 deletions
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26
libprocinfo/include/procinfo/process.h
View file

@ -56,23 +56,25 @@ struct ProcessInfo {
};
// Parse the contents of /proc/<tid>/status into |process_info|.
bool GetProcessInfo(pid_t tid, ProcessInfo* process_info);
bool GetProcessInfo(pid_t tid, ProcessInfo* process_info, std::string* error = nullptr);
// Parse the contents of <fd>/status into |process_info|.
// |fd| should be an fd pointing at a /proc/<pid> directory.
bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info);
bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info, std::string* error = nullptr);
// Fetch the list of threads from a given process's /proc/<pid> directory.
// |fd| should be an fd pointing at a /proc/<pid> directory.
template <typename Collection>
auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
auto GetProcessTidsFromProcPidFd(int fd, Collection* out, std::string* error = nullptr) ->
typename std::enable_if<sizeof(typename Collection::value_type) >= sizeof(pid_t), bool>::type {
out->clear();
int task_fd = openat(fd, "task", O_DIRECTORY | O_RDONLY | O_CLOEXEC);
std::unique_ptr<DIR, int (*)(DIR*)> dir(fdopendir(task_fd), closedir);
if (!dir) {
PLOG(ERROR) << "failed to open task directory";
if (error != nullptr) {
*error = "failed to open task directory";
}
return false;
}
@ -81,7 +83,9 @@ auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
if (strcmp(dent->d_name, ".") != 0 && strcmp(dent->d_name, "..") != 0) {
pid_t tid;
if (!android::base::ParseInt(dent->d_name, &tid, 1, std::numeric_limits<pid_t>::max())) {
LOG(ERROR) << "failed to parse task id: " << dent->d_name;
if (error != nullptr) {
*error = std::string("failed to parse task id: ") + dent->d_name;
}
return false;
}
@ -93,21 +97,25 @@ auto GetProcessTidsFromProcPidFd(int fd, Collection* out) ->
}
template <typename Collection>
auto GetProcessTids(pid_t pid, Collection* out) ->
auto GetProcessTids(pid_t pid, Collection* out, std::string* error = nullptr) ->
typename std::enable_if<sizeof(typename Collection::value_type) >= sizeof(pid_t), bool>::type {
char task_path[PATH_MAX];
if (snprintf(task_path, PATH_MAX, "/proc/%d", pid) >= PATH_MAX) {
LOG(ERROR) << "task path overflow (pid = " << pid << ")";
if (error != nullptr) {
*error = "task path overflow (pid = " + std::to_string(pid) + ")";
}
return false;
}
android::base::unique_fd fd(open(task_path, O_DIRECTORY | O_RDONLY | O_CLOEXEC));
if (fd == -1) {
PLOG(ERROR) << "failed to open " << task_path;
if (error != nullptr) {
*error = std::string("failed to open ") + task_path;
}
return false;
}
return GetProcessTidsFromProcPidFd(fd.get(), out);
return GetProcessTidsFromProcPidFd(fd.get(), out, error);
}
#endif

18
libprocinfo/process.cpp
View file

@ -31,17 +31,19 @@ using android::base::unique_fd;
namespace android {
namespace procinfo {
bool GetProcessInfo(pid_t tid, ProcessInfo* process_info) {
bool GetProcessInfo(pid_t tid, ProcessInfo* process_info, std::string* error) {
char path[PATH_MAX];
snprintf(path, sizeof(path), "/proc/%d", tid);
unique_fd dirfd(open(path, O_DIRECTORY | O_RDONLY));
if (dirfd == -1) {
PLOG(ERROR) << "failed to open " << path;
if (error != nullptr) {
*error = std::string("failed to open ") + path;
}
return false;
}
return GetProcessInfoFromProcPidFd(dirfd.get(), process_info);
return GetProcessInfoFromProcPidFd(dirfd.get(), process_info, error);
}
static ProcessState parse_state(const char* state) {
@ -62,17 +64,21 @@ static ProcessState parse_state(const char* state) {
}
}
bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info) {
bool GetProcessInfoFromProcPidFd(int fd, ProcessInfo* process_info, std::string* error) {
int status_fd = openat(fd, "status", O_RDONLY | O_CLOEXEC);
if (status_fd == -1) {
PLOG(ERROR) << "failed to open status fd in GetProcessInfoFromProcPidFd";
if (error != nullptr) {
*error = "failed to open status fd in GetProcessInfoFromProcPidFd";
}
return false;
}
std::unique_ptr<FILE, decltype(&fclose)> fp(fdopen(status_fd, "r"), fclose);
if (!fp) {
PLOG(ERROR) << "failed to open status file in GetProcessInfoFromProcPidFd";
if (error != nullptr) {
*error = "failed to open status file in GetProcessInfoFromProcPidFd";
}
close(status_fd);
return false;
}