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Diffstat (limited to 'src/vlog_is_on.cc')
| -rw-r--r-- | src/vlog_is_on.cc | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/vlog_is_on.cc b/src/vlog_is_on.cc new file mode 100644 index 000000000000..e8fdbae7dcba --- /dev/null +++ b/src/vlog_is_on.cc @@ -0,0 +1,257 @@ +// Copyright (c) 1999, 2007, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +// +// Author: Ray Sidney and many others +// +// Broken out from logging.cc by Soren Lassen +// logging_unittest.cc covers the functionality herein + +#include "utilities.h" + +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <cstdio> +#include <string> +#include "base/commandlineflags.h" +#include "glog/logging.h" +#include "glog/raw_logging.h" +#include "base/googleinit.h" + +// glog doesn't have annotation +#define ANNOTATE_BENIGN_RACE(address, description) + +using std::string; + +GLOG_DEFINE_int32(v, 0, "Show all VLOG(m) messages for m <= this." +" Overridable by --vmodule."); + +GLOG_DEFINE_string(vmodule, "", "per-module verbose level." +" Argument is a comma-separated list of <module name>=<log level>." +" <module name> is a glob pattern, matched against the filename base" +" (that is, name ignoring .cc/.h./-inl.h)." +" <log level> overrides any value given by --v."); + +_START_GOOGLE_NAMESPACE_ + +namespace glog_internal_namespace_ { + +// Used by logging_unittests.cc so can't make it static here. +GOOGLE_GLOG_DLL_DECL bool SafeFNMatch_(const char* pattern, + size_t patt_len, + const char* str, + size_t str_len); + +// Implementation of fnmatch that does not need 0-termination +// of arguments and does not allocate any memory, +// but we only support "*" and "?" wildcards, not the "[...]" patterns. +// It's not a static function for the unittest. +GOOGLE_GLOG_DLL_DECL bool SafeFNMatch_(const char* pattern, + size_t patt_len, + const char* str, + size_t str_len) { + size_t p = 0; + size_t s = 0; + while (1) { + if (p == patt_len && s == str_len) return true; + if (p == patt_len) return false; + if (s == str_len) return p+1 == patt_len && pattern[p] == '*'; + if (pattern[p] == str[s] || pattern[p] == '?') { + p += 1; + s += 1; + continue; + } + if (pattern[p] == '*') { + if (p+1 == patt_len) return true; + do { + if (SafeFNMatch_(pattern+(p+1), patt_len-(p+1), str+s, str_len-s)) { + return true; + } + s += 1; + } while (s != str_len); + return false; + } + return false; + } +} + +} // namespace glog_internal_namespace_ + +using glog_internal_namespace_::SafeFNMatch_; + +int32 kLogSiteUninitialized = 1000; + +// List of per-module log levels from FLAGS_vmodule. +// Once created each element is never deleted/modified +// except for the vlog_level: other threads will read VModuleInfo blobs +// w/o locks and we'll store pointers to vlog_level at VLOG locations +// that will never go away. +// We can't use an STL struct here as we wouldn't know +// when it's safe to delete/update it: other threads need to use it w/o locks. +struct VModuleInfo { + string module_pattern; + mutable int32 vlog_level; // Conceptually this is an AtomicWord, but it's + // too much work to use AtomicWord type here + // w/o much actual benefit. + const VModuleInfo* next; +}; + +// This protects the following global variables. +static Mutex vmodule_lock; +// Pointer to head of the VModuleInfo list. +// It's a map from module pattern to logging level for those module(s). +static VModuleInfo* vmodule_list = 0; +// Boolean initialization flag. +static bool inited_vmodule = false; + +// L >= vmodule_lock. +static void VLOG2Initializer() { + vmodule_lock.AssertHeld(); + // Can now parse --vmodule flag and initialize mapping of module-specific + // logging levels. + inited_vmodule = false; + const char* vmodule = FLAGS_vmodule.c_str(); + const char* sep; + VModuleInfo* head = NULL; + VModuleInfo* tail = NULL; + while ((sep = strchr(vmodule, '=')) != NULL) { + string pattern(vmodule, sep - vmodule); + int module_level; + if (sscanf(sep, "=%d", &module_level) == 1) { + VModuleInfo* info = new VModuleInfo; + info->module_pattern = pattern; + info->vlog_level = module_level; + if (head) tail->next = info; + else head = info; + tail = info; + } + // Skip past this entry + vmodule = strchr(sep, ','); + if (vmodule == NULL) break; + vmodule++; // Skip past "," + } + if (head) { // Put them into the list at the head: + tail->next = vmodule_list; + vmodule_list = head; + } + inited_vmodule = true; +} + +// This can be called very early, so we use SpinLock and RAW_VLOG here. +int SetVLOGLevel(const char* module_pattern, int log_level) { + int result = FLAGS_v; + int const pattern_len = strlen(module_pattern); + bool found = false; + { + MutexLock l(&vmodule_lock); // protect whole read-modify-write + for (const VModuleInfo* info = vmodule_list; + info != NULL; info = info->next) { + if (info->module_pattern == module_pattern) { + if (!found) { + result = info->vlog_level; + found = true; + } + info->vlog_level = log_level; + } else if (!found && + SafeFNMatch_(info->module_pattern.c_str(), + info->module_pattern.size(), + module_pattern, pattern_len)) { + result = info->vlog_level; + found = true; + } + } + if (!found) { + VModuleInfo* info = new VModuleInfo; + info->module_pattern = module_pattern; + info->vlog_level = log_level; + info->next = vmodule_list; + vmodule_list = info; + } + } + RAW_VLOG(1, "Set VLOG level for \"%s\" to %d", module_pattern, log_level); + return result; +} + +// NOTE: Individual VLOG statements cache the integer log level pointers. +// NOTE: This function must not allocate memory or require any locks. +bool InitVLOG3__(int32** site_flag, int32* site_default, + const char* fname, int32 verbose_level) { + MutexLock l(&vmodule_lock); + bool read_vmodule_flag = inited_vmodule; + if (!read_vmodule_flag) { + VLOG2Initializer(); + } + + // protect the errno global in case someone writes: + // VLOG(..) << "The last error was " << strerror(errno) + int old_errno = errno; + + // site_default normally points to FLAGS_v + int32* site_flag_value = site_default; + + // Get basename for file + const char* base = strrchr(fname, '/'); + base = base ? (base+1) : fname; + const char* base_end = strchr(base, '.'); + size_t base_length = base_end ? size_t(base_end - base) : strlen(base); + + // Trim out trailing "-inl" if any + if (base_length >= 4 && (memcmp(base+base_length-4, "-inl", 4) == 0)) { + base_length -= 4; + } + + // TODO: Trim out _unittest suffix? Perhaps it is better to have + // the extra control and just leave it there. + + // find target in vector of modules, replace site_flag_value with + // a module-specific verbose level, if any. + for (const VModuleInfo* info = vmodule_list; + info != NULL; info = info->next) { + if (SafeFNMatch_(info->module_pattern.c_str(), info->module_pattern.size(), + base, base_length)) { + site_flag_value = &info->vlog_level; + // value at info->vlog_level is now what controls + // the VLOG at the caller site forever + break; + } + } + + // Cache the vlog value pointer if --vmodule flag has been parsed. + ANNOTATE_BENIGN_RACE(site_flag, + "*site_flag may be written by several threads," + " but the value will be the same"); + if (read_vmodule_flag) *site_flag = site_flag_value; + + // restore the errno in case something recoverable went wrong during + // the initialization of the VLOG mechanism (see above note "protect the..") + errno = old_errno; + return *site_flag_value >= verbose_level; +} + +_END_GOOGLE_NAMESPACE_ |