| File: | root/firefox-clang/toolkit/crashreporter/breakpad-client/linux/minidump_writer/cpu_set.h |
| Warning: | line 85, column 9 Value stored to 'item_len' is never read |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
| 1 | // Copyright (c) 2013, Google Inc. |
| 2 | // All rights reserved. |
| 3 | // |
| 4 | // Redistribution and use in source and binary forms, with or without |
| 5 | // modification, are permitted provided that the following conditions are |
| 6 | // met: |
| 7 | // |
| 8 | // * Redistributions of source code must retain the above copyright |
| 9 | // notice, this list of conditions and the following disclaimer. |
| 10 | // * Redistributions in binary form must reproduce the above |
| 11 | // copyright notice, this list of conditions and the following disclaimer |
| 12 | // in the documentation and/or other materials provided with the |
| 13 | // distribution. |
| 14 | // * Neither the name of Google Inc. nor the names of its |
| 15 | // contributors may be used to endorse or promote products derived from |
| 16 | // this software without specific prior written permission. |
| 17 | // |
| 18 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 21 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 22 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 23 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 24 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 28 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | |
| 30 | #ifndef CLIENT_LINUX_MINIDUMP_WRITER_CPU_SET_H_ |
| 31 | #define CLIENT_LINUX_MINIDUMP_WRITER_CPU_SET_H_ |
| 32 | |
| 33 | #include <stdint.h> |
| 34 | #include <assert.h> |
| 35 | #include <string.h> |
| 36 | |
| 37 | #include "common/linux/linux_libc_support.h" |
| 38 | #include "third_party/lss/linux_syscall_support.h" |
| 39 | |
| 40 | namespace google_breakpad { |
| 41 | |
| 42 | // Helper class used to model a set of CPUs, as read from sysfs |
| 43 | // files like /sys/devices/system/cpu/present |
| 44 | // See See http://www.kernel.org/doc/Documentation/cputopology.txt |
| 45 | class CpuSet { |
| 46 | public: |
| 47 | // The maximum number of supported CPUs. |
| 48 | static const size_t kMaxCpus = 1024; |
| 49 | |
| 50 | CpuSet() { |
| 51 | my_memset(mask_, 0, sizeof(mask_)); |
| 52 | } |
| 53 | |
| 54 | // Parse a sysfs file to extract the corresponding CPU set. |
| 55 | bool ParseSysFile(int fd) { |
| 56 | char buffer[512]; |
| 57 | int ret = sys_read(fd, buffer, sizeof(buffer)-1); |
| 58 | if (ret < 0) |
| 59 | return false; |
| 60 | |
| 61 | buffer[ret] = '\0'; |
| 62 | |
| 63 | // Expected format: comma-separated list of items, where each |
| 64 | // item can be a decimal integer, or two decimal integers separated |
| 65 | // by a dash. |
| 66 | // E.g.: |
| 67 | // 0 |
| 68 | // 0,1,2,3 |
| 69 | // 0-3 |
| 70 | // 1,10-23 |
| 71 | const char* p = buffer; |
| 72 | const char* p_end = p + ret; |
| 73 | while (p < p_end) { |
| 74 | // Skip leading space, if any |
| 75 | while (p < p_end && my_isspace(*p)) |
| 76 | p++; |
| 77 | |
| 78 | // Find start and size of current item. |
| 79 | const char* item = p; |
| 80 | size_t item_len = static_cast<size_t>(p_end - p); |
| 81 | const char* item_next = |
| 82 | static_cast<const char*>(my_memchr(p, ',', item_len)); |
| 83 | if (item_next != NULL__null) { |
| 84 | p = item_next + 1; |
| 85 | item_len = static_cast<size_t>(item_next - item); |
Value stored to 'item_len' is never read | |
| 86 | } else { |
| 87 | p = p_end; |
| 88 | item_next = p_end; |
| 89 | } |
| 90 | |
| 91 | // Ignore trailing spaces. |
| 92 | while (item_next > item && my_isspace(item_next[-1])) |
| 93 | item_next--; |
| 94 | |
| 95 | // skip empty items. |
| 96 | if (item_next == item) |
| 97 | continue; |
| 98 | |
| 99 | // read first decimal value. |
| 100 | uintptr_t start = 0; |
| 101 | const char* next = my_read_decimal_ptr(&start, item); |
| 102 | uintptr_t end = start; |
| 103 | if (*next == '-') |
| 104 | my_read_decimal_ptr(&end, next+1); |
| 105 | |
| 106 | while (start <= end) |
| 107 | SetBit(start++); |
| 108 | } |
| 109 | return true; |
| 110 | } |
| 111 | |
| 112 | // Intersect this CPU set with another one. |
| 113 | void IntersectWith(const CpuSet& other) { |
| 114 | for (size_t nn = 0; nn < kMaskWordCount; ++nn) |
| 115 | mask_[nn] &= other.mask_[nn]; |
| 116 | } |
| 117 | |
| 118 | // Return the number of CPUs in this set. |
| 119 | int GetCount() { |
| 120 | int result = 0; |
| 121 | for (size_t nn = 0; nn < kMaskWordCount; ++nn) { |
| 122 | result += __builtin_popcount(mask_[nn]); |
| 123 | } |
| 124 | return result; |
| 125 | } |
| 126 | |
| 127 | private: |
| 128 | void SetBit(uintptr_t index) { |
| 129 | size_t nn = static_cast<size_t>(index); |
| 130 | if (nn < kMaxCpus) |
| 131 | mask_[nn / kMaskWordBits] |= (1U << (nn % kMaskWordBits)); |
| 132 | } |
| 133 | |
| 134 | typedef uint32_t MaskWordType; |
| 135 | static const size_t kMaskWordBits = 8*sizeof(MaskWordType); |
| 136 | static const size_t kMaskWordCount = |
| 137 | (kMaxCpus + kMaskWordBits - 1) / kMaskWordBits; |
| 138 | |
| 139 | MaskWordType mask_[kMaskWordCount]; |
| 140 | }; |
| 141 | |
| 142 | } // namespace google_breakpad |
| 143 | |
| 144 | #endif // CLIENT_LINUX_MINIDUMP_WRITER_CPU_SET_H_ |