在使用 XCode 测试和调试您的应用程序时,您可以使用它logMemUsage()
函数 NSLog 已用/可用空间并在测试应用程序时观察情况如何。此函数记录使用情况> 100kb 的任何变化。它像这样输出到调试日志(在模拟器上,可用空间很大):
2011-11-02 21:55:58.928 hello[971:207] Memory used 21884.9 (+21885), free 1838366.8 kb
2011-11-02 21:55:59.936 hello[971:207] Memory used 28512.3 (+6627), free 1830809.6 kb
2011-11-02 21:56:01.936 hello[971:207] Memory used 28803.1 ( +291), free 1830129.6 kb
2011-11-02 21:56:02.936 hello[971:207] Memory used 29712.4 ( +909), free 1830142.0 kb
您决定打电话到哪里logMemUsage
在你的应用程序中。我碰巧有一个函数每秒被计时器调用一次,所以我把它放在那里。我建议使用#ifdef
围绕这些,因此此代码仅包含在调试版本中。
#import "mach/mach.h"
vm_size_t usedMemory(void) {
struct task_basic_info info;
mach_msg_type_number_t size = sizeof(info);
kern_return_t kerr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &size);
return (kerr == KERN_SUCCESS) ? info.resident_size : 0; // size in bytes
}
vm_size_t freeMemory(void) {
mach_port_t host_port = mach_host_self();
mach_msg_type_number_t host_size = sizeof(vm_statistics_data_t) / sizeof(integer_t);
vm_size_t pagesize;
vm_statistics_data_t vm_stat;
host_page_size(host_port, &pagesize);
(void) host_statistics(host_port, HOST_VM_INFO, (host_info_t)&vm_stat, &host_size);
return vm_stat.free_count * pagesize;
}
void logMemUsage(void) {
// compute memory usage and log if different by >= 100k
static long prevMemUsage = 0;
long curMemUsage = usedMemory();
long memUsageDiff = curMemUsage - prevMemUsage;
if (memUsageDiff > 100000 || memUsageDiff < -100000) {
prevMemUsage = curMemUsage;
NSLog(@"Memory used %7.1f (%+5.0f), free %7.1f kb", curMemUsage/1000.0f, memUsageDiff/1000.0f, freeMemory()/1000.0f);
}
}