win+linux平台C语言获取进程的线程数量
进程内线程数量的浮动状态，是衡量软件是否稳定的一个指标。线程数量控制不好，将影响软件中其他功能的正常运行，可能会造成出现“Resource temporarily unavailable”的错误，乃至导致应用退出的可能。
1、linux平台，proc/pid/stat对应的内容结构
typedef struct
{/** 01 */ pid_t pid; /** 进程号，其允许的最大值，请查看/proc/sys/kernel/pid_max *//** 02 */ char comm[FILENAME_MAX]; /** 进程的名字，不包括路径 *//** 03 */ char state; /** 进程的状态 *//** 04 */ pid_t ppid; /** 父进程号 *//** 05 */ pid_t pgrp; /** 进程组号 *//** 06 */ pid_t session; /** 进程会话号 *//** 07 */ int tty_nr; /** The tty the process uses *//** 08 */ pid_t tpgid; /** The tty the process uses *//** 09 */ unsigned int flags; /** The kernel flags word of the process (%lu before Linux 2.6.22) *//** 10 */ unsigned long minflt; /** The number of minor faults the process has made which have not required loading a memory page from disk *//** 11 */ unsigned long cminflt; /** The number of minor faults that the process's waited-for children have made *//** 12 */ unsigned long majflt; /** The number of major faults the process has made which have required loading a memory page from disk *//** 13 */ unsigned long cmajflt; /** The number of major faults that the process's waited-for children have made *//** 14 */ unsigned long utime; /** The number of jiffies that this process has been scheduled in user mode *//** 15 */ unsigned long stime; /** The number of jiffies that this process has been scheduled in kernel mode *//** 16 */ long cutime; /** The number of jiffies that this process's waited-for children have been scheduled in user mode *//** 17 */ long cstime; /** The number of jiffies that this process's waited-for children have been scheduled in kernel mode *//** 18 */ long priority; /** The standard nice value, plus fifteen. The value is never negative in the kernel *//** 19 */ long nice; /** The nice value ranges from 19 (nicest) to -19 (not nice to others) *//** 20 */ long num_threads; /** Number of threads in this process (since Linux 2.6). Before kernel 2.6, this field was hard coded to 0 as a placeholder *//** 21 */ long itrealvalue; /** The time in jiffies before the next SIGALRM is sent to the process due to an interval timer.2.6.17, this field is no longer maintained, and is hard coded as 0 *//** 22 */ long long starttime; /** The time in jiffies the process started after system boot *//** 23 */ unsigned long vsize; /** Virtual memory size in bytes *//** 24 */ long rss; /** Resident Set Size: number of pages the process has in real memory, minus 3 for administrative purposes *//** 25 */ unsigned long rlim; /** Current limit in bytes on the rss of the process (usually 4294967295 on i386) *//** 26 */ unsigned long startcode; /** The address above which program text can run *//** 27 */ unsigned long endcode; /** The address below which program text can run *//** 28 */ unsigned long startstack; /** The address of the start of the stack *//** 29 */ unsigned long kstkesp; /** The current value of esp (stack pointer), as found in the kernel stack page for the process *//** 30 */ unsigned long kstkeip; /** The current EIP (instruction pointer) *//** 31 */ unsigned long signal; /** The bitmap of pending signals *//** 32 */ unsigned long blocked; /** The bitmap of blocked signals *//** 33 */ unsigned long sigignore; /** The bitmap of ignored signals *//** 34 */ unsigned long sigcatch; /** The bitmap of caught signals *//** 35 */ unsigned long nswap; /** Number of pages swapped (not maintained). *//** 36 */ unsigned long cnswap; /** Cumulative nswap for child processes (not maintained) *//** 37 */ int exit_signal; /** Signal to be sent to parent when we die (since Linux 2.1.22) *//** 38 */ int processor; /** CPU number last executed on (since Linux 2.2.8) */
}process_info_t;2、win+linux平台C语言获取进程内线程数量get_thread_count()
/*根据当前进程号，获取进程下线程数目*/
int get_thread_count()
{int threads_in_process = 0;
#if defined (ACE_LINUX)char filename[FILENAME_MAX];ACE_OS::snprintf(filename, sizeof(filename)-1, "/proc/%u/stat", getpid());FILE* fp = fopen(filename, "r");if (NULL == fp) return -1;char line[LINE_MAX];int filed_number = 38;process_info_t process_info;char* linep = fgets(line, sizeof(line)-1, fp);if (NULL == linep) return -1;sscanf(line, "%d%s%s%d%d""%d%d%d%u%lu""%lu%lu%lu%lu%lu""%ld%ld%ld%ld%ld""%ld%lld%lu%ld%lu""%lu%lu%lu%lu%lu""%lu%lu%lu%lu%lu""%lu%d%d"/** 01 */ ,&process_info.pid/** 02 */ , process_info.comm/** 03 */ ,&process_info.state/** 04 */ ,&process_info.ppid/** 05 */ ,&process_info.pgrp/** 06 */ ,&process_info.session/** 07 */ ,&process_info.tty_nr/** 08 */ ,&process_info.tpgid/** 09 */ ,&process_info.flags/** 10 */ ,&process_info.minflt/** 11 */ ,&process_info.cminflt/** 12 */ ,&process_info.majflt/** 13 */ ,&process_info.cmajflt/** 14 */ ,&process_info.utime/** 15 */ ,&process_info.stime/** 16 */ ,&process_info.cutime/** 17 */ ,&process_info.cstime/** 18 */ ,&process_info.priority/** 19 */ ,&process_info.nice/** 20 */ ,&process_info.num_threads/** 21 */ ,&process_info.itrealvalue/** 22 */ ,&process_info.starttime/** 23 */ ,&process_info.vsize/** 24 */ ,&process_info.rss/** 25 */ ,&process_info.rlim/** 26 */ ,&process_info.startcode/** 27 */ ,&process_info.endcode/** 28 */ ,&process_info.startstack/** 29 */ ,&process_info.kstkesp/** 30 */ ,&process_info.kstkeip/** 31 */ ,&process_info.signal/** 32 */ ,&process_info.blocked/** 33 */ ,&process_info.sigignore/** 34 */ ,&process_info.sigcatch/** 35 */ ,&process_info.nswap/** 36 */ ,&process_info.cnswap/** 37 */ ,&process_info.exit_signal/** 38 */ ,&process_info.processor);fclose(fp);threads_in_process = (int)process_info.num_threads;
#elseint i = 0;PROCESSENTRY32 pe32;pe32.dwSize = sizeof(pe32);int processid = GetCurrentProcessId();HANDLE hProcessSnap = ::CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);if (hProcessSnap == INVALID_HANDLE_VALUE){fprintf(stderr, "SkyDDS Warning, CreateToolhelp32Snapshot() failed. error code:%d.\n", GetLastError());return 0;}BOOL bMore = ::Process32First(hProcessSnap, &pe32);while (bMore){if (pe32.th32ProcessID == processid){return pe32.cntThreads;}bMore = Process32Next(hProcessSnap, &pe32);i++;}#endifreturn threads_in_process;
}