diff options
Diffstat (limited to 'absl/base/internal/sysinfo.cc')
-rw-r--r-- | absl/base/internal/sysinfo.cc | 116 |
1 files changed, 39 insertions, 77 deletions
diff --git a/absl/base/internal/sysinfo.cc b/absl/base/internal/sysinfo.cc index c8366df1..8bcc4faf 100644 --- a/absl/base/internal/sysinfo.cc +++ b/absl/base/internal/sysinfo.cc @@ -41,6 +41,7 @@ #include <string.h> #include <cassert> +#include <cerrno> #include <cstdint> #include <cstdio> #include <cstdlib> @@ -117,7 +118,7 @@ int Win32NumCPUs() { } } free(info); - return logicalProcessorCount; + return static_cast<int>(logicalProcessorCount); } #endif @@ -128,7 +129,7 @@ static int GetNumCPUs() { #if defined(__myriad2__) return 1; #elif defined(_WIN32) - const unsigned hardware_concurrency = Win32NumCPUs(); + const int hardware_concurrency = Win32NumCPUs(); return hardware_concurrency ? hardware_concurrency : 1; #elif defined(_AIX) return sysconf(_SC_NPROCESSORS_ONLN); @@ -136,7 +137,7 @@ static int GetNumCPUs() { // Other possibilities: // - Read /sys/devices/system/cpu/online and use cpumask_parse() // - sysconf(_SC_NPROCESSORS_ONLN) - return std::thread::hardware_concurrency(); + return static_cast<int>(std::thread::hardware_concurrency()); #endif } @@ -159,7 +160,7 @@ static double GetNominalCPUFrequency() { DWORD type = 0; DWORD data = 0; DWORD data_size = sizeof(data); - auto result = RegQueryValueExA(key, "~MHz", 0, &type, + auto result = RegQueryValueExA(key, "~MHz", nullptr, &type, reinterpret_cast<LPBYTE>(&data), &data_size); RegCloseKey(key); if (result == ERROR_SUCCESS && type == REG_DWORD && @@ -189,12 +190,21 @@ static double GetNominalCPUFrequency() { // and the memory location pointed to by value is set to the value read. static bool ReadLongFromFile(const char *file, long *value) { bool ret = false; - int fd = open(file, O_RDONLY); +#if defined(_POSIX_C_SOURCE) + const int file_mode = (O_RDONLY | O_CLOEXEC); +#else + const int file_mode = O_RDONLY; +#endif + + int fd = open(file, file_mode); if (fd != -1) { char line[1024]; char *err; memset(line, '\0', sizeof(line)); - int len = read(fd, line, sizeof(line) - 1); + ssize_t len; + do { + len = read(fd, line, sizeof(line) - 1); + } while (len < 0 && errno == EINTR); if (len <= 0) { ret = false; } else { @@ -222,8 +232,8 @@ static int64_t ReadMonotonicClockNanos() { int rc = clock_gettime(CLOCK_MONOTONIC, &t); #endif if (rc != 0) { - perror("clock_gettime() failed"); - abort(); + ABSL_INTERNAL_LOG( + FATAL, "clock_gettime() failed: (" + std::to_string(errno) + ")"); } return int64_t{t.tv_sec} * 1000000000 + t.tv_nsec; } @@ -376,7 +386,7 @@ pid_t GetTID() { #endif pid_t GetTID() { - return syscall(SYS_gettid); + return static_cast<pid_t>(syscall(SYS_gettid)); } #elif defined(__akaros__) @@ -411,81 +421,33 @@ pid_t GetTID() { return tid; } -#else +#elif defined(__APPLE__) -// Fallback implementation of GetTID using pthread_getspecific. -ABSL_CONST_INIT static once_flag tid_once; -ABSL_CONST_INIT static pthread_key_t tid_key; -ABSL_CONST_INIT static absl::base_internal::SpinLock tid_lock( - absl::kConstInit, base_internal::SCHEDULE_KERNEL_ONLY); - -// We set a bit per thread in this array to indicate that an ID is in -// use. ID 0 is unused because it is the default value returned by -// pthread_getspecific(). -ABSL_CONST_INIT static std::vector<uint32_t> *tid_array - ABSL_GUARDED_BY(tid_lock) = nullptr; -static constexpr int kBitsPerWord = 32; // tid_array is uint32_t. - -// Returns the TID to tid_array. -static void FreeTID(void *v) { - intptr_t tid = reinterpret_cast<intptr_t>(v); - int word = tid / kBitsPerWord; - uint32_t mask = ~(1u << (tid % kBitsPerWord)); - absl::base_internal::SpinLockHolder lock(&tid_lock); - assert(0 <= word && static_cast<size_t>(word) < tid_array->size()); - (*tid_array)[word] &= mask; +pid_t GetTID() { + uint64_t tid; + // `nullptr` here implies this thread. This only fails if the specified + // thread is invalid or the pointer-to-tid is null, so we needn't worry about + // it. + pthread_threadid_np(nullptr, &tid); + return static_cast<pid_t>(tid); } -static void InitGetTID() { - if (pthread_key_create(&tid_key, FreeTID) != 0) { - // The logging system calls GetTID() so it can't be used here. - perror("pthread_key_create failed"); - abort(); - } - - // Initialize tid_array. - absl::base_internal::SpinLockHolder lock(&tid_lock); - tid_array = new std::vector<uint32_t>(1); - (*tid_array)[0] = 1; // ID 0 is never-allocated. -} +#elif defined(__native_client__) -// Return a per-thread small integer ID from pthread's thread-specific data. pid_t GetTID() { - absl::call_once(tid_once, InitGetTID); - - intptr_t tid = reinterpret_cast<intptr_t>(pthread_getspecific(tid_key)); - if (tid != 0) { - return tid; - } - - int bit; // tid_array[word] = 1u << bit; - size_t word; - { - // Search for the first unused ID. - absl::base_internal::SpinLockHolder lock(&tid_lock); - // First search for a word in the array that is not all ones. - word = 0; - while (word < tid_array->size() && ~(*tid_array)[word] == 0) { - ++word; - } - if (word == tid_array->size()) { - tid_array->push_back(0); // No space left, add kBitsPerWord more IDs. - } - // Search for a zero bit in the word. - bit = 0; - while (bit < kBitsPerWord && (((*tid_array)[word] >> bit) & 1) != 0) { - ++bit; - } - tid = (word * kBitsPerWord) + bit; - (*tid_array)[word] |= 1u << bit; // Mark the TID as allocated. - } + auto* thread = pthread_self(); + static_assert(sizeof(pid_t) == sizeof(thread), + "In NaCL int expected to be the same size as a pointer"); + return reinterpret_cast<pid_t>(thread); +} - if (pthread_setspecific(tid_key, reinterpret_cast<void *>(tid)) != 0) { - perror("pthread_setspecific failed"); - abort(); - } +#else - return static_cast<pid_t>(tid); +// Fallback implementation of `GetTID` using `pthread_self`. +pid_t GetTID() { + // `pthread_t` need not be arithmetic per POSIX; platforms where it isn't + // should be handled above. + return static_cast<pid_t>(pthread_self()); } #endif |