gc.tar.gz_garbage_garbage collection_回收站_垃圾回收

/* * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. * * Permission is hereby granted to use or copy this program * for any purpose, provided the above notices are retained on all copies. * Permission to modify the code and to distribute modified code is granted, * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. */ # include "private/gc_priv.h" # if defined(LINUX) && !defined(POWERPC) # include <linux/version.h> # if (LINUX_VERSION_CODE <= 0x10400) /* Ugly hack to get struct sigcontext_struct definition. Required */ /* for some early 1.3.X releases. Will hopefully go away soon. */ /* in some later Linux releases, asm/sigcontext.h may have to */ /* be included instead. */ # define __KERNEL__ # include <asm/signal.h> # undef __KERNEL__ # else /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */ /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */ /* prototypes, so we have to include the top-level sigcontext.h to */ /* make sure the former gets defined to be the latter if appropriate. */ # include <features.h> # if 2 <= __GLIBC__ # if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__ /* glibc 2.1 no longer has sigcontext.h. But signal.h */ /* has the right declaration for glibc 2.1. */ # include <sigcontext.h> # endif /* 0 == __GLIBC_MINOR__ */ # else /* not 2 <= __GLIBC__ */ /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */ /* one. Check LINUX_VERSION_CODE to see which we should reference. */ # include <asm/sigcontext.h> # endif /* 2 <= __GLIBC__ */ # endif # endif # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \ && !defined(MSWINCE) # include <sys/types.h> # if !defined(MSWIN32) && !defined(SUNOS4) # include <unistd.h> # endif # endif # include <stdio.h> # if defined(MSWINCE) # define SIGSEGV 0 /* value is irrelevant */ # else # include <signal.h> # endif /* Blatantly OS dependent routines, except for those that are related */ /* to dynamic loading. */ # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START) # define NEED_FIND_LIMIT # endif # if !defined(STACKBOTTOM) && defined(HEURISTIC2) # define NEED_FIND_LIMIT # endif # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR) # define NEED_FIND_LIMIT # endif # if (defined(SVR4) || defined(AUX) || defined(DGUX) \ || (defined(LINUX) && defined(SPARC))) && !defined(PCR) # define NEED_FIND_LIMIT # endif #if defined(FREEBSD) && defined(I386) # include <machine/trap.h> # if !defined(PCR) # define NEED_FIND_LIMIT # endif #endif #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) \ && !defined(NEED_FIND_LIMIT) /* Used by GC_init_netbsd_elf() below. */ # define NEED_FIND_LIMIT #endif #ifdef NEED_FIND_LIMIT # include <setjmp.h> #endif #ifdef AMIGA # define GC_AMIGA_DEF # include "AmigaOS.c" # undef GC_AMIGA_DEF #endif #if defined(MSWIN32) || defined(MSWINCE) # define WIN32_LEAN_AND_MEAN # define NOSERVICE # include <windows.h> #endif #ifdef MACOS # include <Processes.h> #endif #ifdef IRIX5 # include <sys/uio.h> # include <malloc.h> /* for locking */ #endif #if defined(USE_MMAP) || defined(USE_MUNMAP) # ifndef USE_MMAP --> USE_MUNMAP requires USE_MMAP # endif # include <sys/types.h> # include <sys/mman.h> # include <sys/stat.h> # include <errno.h> #endif #ifdef UNIX_LIKE # include <fcntl.h> # if defined(SUNOS5SIGS) && !defined(FREEBSD) # include <sys/siginfo.h> # endif /* Define SETJMP and friends to be the version that restores */ /* the signal mask. */ # define SETJMP(env) sigsetjmp(env, 1) # define LONGJMP(env, val) siglongjmp(env, val) # define JMP_BUF sigjmp_buf #else # define SETJMP(env) setjmp(env) # define LONGJMP(env, val) longjmp(env, val) # define JMP_BUF jmp_buf #endif #ifdef DARWIN /* for get_etext and friends */ #include <mach-o/getsect.h> #endif #ifdef DJGPP /* Apparently necessary for djgpp 2.01. May cause problems with */ /* other versions. */ typedef long unsigned int caddr_t; #endif #ifdef PCR # include "il/PCR_IL.h" # include "th/PCR_ThCtl.h" # include "mm/PCR_MM.h" #endif #if !defined(NO_EXECUTE_PERMISSION) # define OPT_PROT_EXEC PROT_EXEC #else # define OPT_PROT_EXEC 0 #endif #if defined(LINUX) && \ (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG)) /* We need to parse /proc/self/maps, either to find dynamic libraries, */ /* and/or to find the register backing store base (IA64). Do it once */ /* here. */ #define READ read /* Repeatedly perform a read call until the buffer is filled or */ /* we encounter EOF. */ ssize_t GC_repeat_read(int fd, char *buf, size_t count) { ssize_t num_read = 0; ssize_t result; while (num_read < count) { result = READ(fd, buf + num_read, count - num_read); if (result < 0) return result; if (result == 0) break; num_read += result; } return num_read; } /* * Apply fn to a buffer containing the contents of /proc/self/maps. * Return the result of fn or, if we failed, 0. * We currently do nothing to /proc/self/maps other than simply read * it. This code could be simplified if we could determine its size * ahead of time. */ word GC_apply_to_maps(word (*fn)(char *)) { int f; int result; size_t maps_size = 4000; /* Initial guess. */ static char init_buf[1]; static char *maps_buf = init_buf; static size_t maps_buf_sz = 1; /* Read /proc/self/maps, growing maps_buf as necessary. */ /* Note that we may not allocate conventionally, and */ /* thus can't use stdio. */ do { if (maps_size >= maps_buf_sz) { /* Grow only by powers of 2, since we leak "too small" buffers. */ while (maps_size >= maps_buf_sz) maps_buf_sz *= 2; maps_buf = GC_scratch_alloc(maps_buf_sz); if (maps_buf == 0) return 0; } f = open("/proc/self/maps", O_RDONLY); if (-1 == f) return 0; maps_size = 0; do { result = GC_repeat_read(f, maps_buf, maps_buf_sz-1); if (result <= 0) return 0; maps_size += result; } while (result == maps_buf_sz-1); close(f); } while (maps_size >= maps_buf_sz); maps_buf[maps_size] = '\0'; /* Apply fn to result. */ return fn(maps_buf); } #endif /* Need GC_apply_to_maps */ #if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64)) // // GC_parse_map_entry parses an entry from /proc/self/maps so we can // locate all writable data segments that belong to shared libraries. // The format of one of these entries and the fields we care about // is as follows: // XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n // ^^^^^^^^ ^^^^^^^^ ^^^^ ^^ // start end prot maj_dev // 0 9 18 32 // // For 64 bit ABIs: // 0 17 34 56 // // The parser is called with a pointer to the entry and the return value // is either NULL or is advanced to the next entry(the byte after the // trailing '\n'.) // #if CPP_WORDSZ == 32 # define OFFSET_MAP_START 0 # define OFFSET_MAP_END 9 # define OFFSET_MAP_PROT 18 # define OFFSET_MAP_MAJDEV 32 # define ADDR_WIDTH 8 #endif #if CPP_WORDSZ == 64 # define OFFSET_MAP_START 0 # define OFFSET_MAP_END 17 # define OFFSET_MAP_PROT 34 # define OFFSET_MAP_MAJDEV 56 # define ADDR_WIDTH 16 #endif /* * Assig