小编Eri*_*ric的帖子

我显然导致设备(iPad)耗尽内存,所以它放弃了我的应用程序.我正在试图理解正在发生的事情,因为Instruments正在告诉我,我使用的是大约80Mb,并且设备上没有运行其他应用程序.

我发现这段代码片段要求iOS下的Mach系统获取内存统计信息:

#import <mach/mach.h>
#import <mach/mach_host.h>

static void print_free_memory () {
mach_port_t host_port;
mach_msg_type_number_t host_size;
vm_size_t pagesize;

host_port = mach_host_self();
host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
host_page_size(host_port, &pagesize);       

vm_statistics_data_t vm_stat;

if (host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size) != KERN_SUCCESS)
    NSLog(@"Failed to fetch vm statistics");

/* Stats in bytes */
natural_t mem_used = (vm_stat.active_count +
                      vm_stat.inactive_count +
                      vm_stat.wire_count) * pagesize;
natural_t mem_free = vm_stat.free_count * pagesize;
natural_t mem_total = mem_used + mem_free;
NSLog(@"used: %u free: %u total: %u", mem_used, mem_free, mem_total);
}

当我使用此函数获取三个内存值时,我发现即使mem_used总数没有发生太大变化,mem_total值也会下降.这是两个连续的输出行:

<Warning>: …

更新:

我刚刚意识到您可以通过设置LD_TRACE_ARCHIVES和LD_TRACE_DYLIBS环境变量然后直接在命令行上运行链接器命令来获取更多信息.这是我正在执行的,然后是它的输出(虽然我用<short-text>字符串替换了一些非常长的路径和名称):

/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2
-arch i386
-isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk
-L<path_to_project>/build/Debug-iphonesimulator
-L<path_to_static_libs>
-F<path_to_project>/build/Debug-iphonesimulator
-filelist <path_to_project>/build/<project_name>.build/Debug-iphonesimulator/<project_name>.build/Objects-normal/i386/<project_name>.LinkFileList
-mmacosx-version-min=10.6
--verbose
-lproject_lib
-Xlinker -objc_abi_version
-Xlinker 2
-framework Foundation -framework UIKit -framework OpenGLES -framework QuartzCore
-o <path_to_project>/build/Debug-iphonesimulator/<project_name>.app/<project_name>

Using built-in specs.
Target: i686-apple-darwin10
Thread model: posix
gcc version 4.2.1 (Apple Inc. build 5664)
/Developer/usr/bin/../libexec/gcc/i686-apple-darwin10/4.2.1/collect2
-dynamic -arch i386 -macosx_version_min 10.6
-syslibroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk
-weak_reference_mismatches non-weak
-o <path_to_project>/build/Debug-iphonesimulator/<project_name>.app/<project_name>
-lcrt1.10.6.o
-L<path_to_project>/build/Debug-iphonesimulator
-L<path_to_static_libs>
-L/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1
-L/Developer/usr/bin/../lib/gcc
-L/usr/lib/gcc/i686-apple-darwin10/4.2.1
-L/usr/lib/gcc/i686-apple-darwin10/4.2.1
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1/../../../i686-apple-darwin10/4.2.1
-L/Developer/usr/bin/../lib/gcc/i686-apple-darwin10/4.2.1/../../..
-L/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk/usr/lib/gcc/i686-apple-darwin10/4.2.1/../../..
-filelist <path_to_project>/build/<project_name>.build/Debug-iphonesimulator/<project_name>.build/Objects-normal/i386/<project_name>.LinkFileList
-lproject_lib
-objc_abi_version 2
-framework Foundation -framework UIKit -framework OpenGLES …